2. Schizophrenia Spectrum and Other Psychotic Disorders
2.1. Schizotypal (Personality) Disorder
2.2. Delusional Disorder
2.3. Brief Psychotic Disorder
2.4. Schizophreniform Disorder
2.5. Schizophrenia
2.6. Schizoaffective Disorder
2.7. Substance/Medication-Induced Psychotic Disorder
2.8. Psychotic Disorder Due to Another Medical Condition
2.9. Catatonia Associated With Another Mental Disorder (Catatonia Specifier)
2.10. Catatonic Disorder Due to Another Medical Condition
SchiZOphrenia spectrum and other psychotic disorders include schizophrenia,
other psychotic disorders, and schizotypal (personality) disorder. They are defined by abnormalities
in one or more of the following five domains: delusions, hallucinations, disorganized
thinking (speech), grossly disorganized or abnormal motor behavior (including
catatonia), and negative symptoms.
Delusions are fixed beliefs that are not amenable to change in light of conflicting evidence. Their content may include a variety of themes (e.g., persecutory, referential, somatic, religious, grandiose). Persecutory delusions (i.e., belief that one is going to be harmed, harassed, and so forth by an individual, organization, or other group) are most common. Referential delusions (i.e., belief that certain gestures, comments, environmental cues, and so forth are directed at oneself) are also common. Grandiose delusions (i.e., when an individual believes that he or she has exceptional abilities, wealth, or fame) and erotomanie delusions (i.e., when an individual believes falsely that another person is in love with him or her) are also seen. Nihilistic delusions involve the conviction that a major catastrophe will occur, and somatic delusions focus on preoccupations regarding health and organ function.
Delusions are deemed bizarre if they are clearly implausible and not understandable to same-culture peers and do not derive from ordinary life experiences. An example of a bizarre delusion is the belief that an outside force has removed his or her internal organs and replaced them with someone else's organs without leaving any wounds or scars. An example of a nonbizarre delusion is the belief that one is under surveillance by the police, despite a lack of convincing evidence. Delusions that express a loss of control over mind or body are generally considered to be bizarre; these include the belief that one's thoughts have been "removed" by some outside force {thought withdrawal), that alien thoughts have been put into one's mind (thought insertion), or that one's body or actions are being acted on or manipulated by some outside force (delusions of control). The distinction between a delusion and a strongly held idea is sometimes difficult to make and depends in part on the degree of conviction with which the belief is held despite clear or reasonable contradictory evidence regarding its veracity.
Hallucinations are perception-like experiences that occur without an external stimulus. They are vivid and clear, with the full force and impact of normal perceptions, and not under voluntary control. They may occur in any sensory modality, but auditory hallucinations are the most common in schizophrenia and related disorders. Auditory hallucinations are usually experienced as voices, whether familiar or unfamiliar, that are perceived as distinct from the individual's own thoughts. The hallucinations must occur in the context of a clear sensorium; those that occur while falling asleep (hypnagogic) or waking up (hypnopompic) are considered to be within the range of normal experience. Hallucinations may be a normal part of religious experience in certain cultural contexts.
Disorganized thinking (formal thought disorder) is typically inferred from the individual's speech. The individual may switch from one topic to another {derailment or loose associations). Answers to questions may be obliquely related or completely unrelated (tangentiality). Rarely, speech may be so severely disorganized that it is nearly incomprehensible and resembles receptive aphasia in its linguistic disorganization {incoherence or "word salad"). Because mildly disorganized speech is common and nonspecific, the symptom must be severe enough to substantially impair effective communication. The severity of the impairment may be difficult to evaluate if the person making the diagnosis comes from a different linguistic background than that of the person being examined. Less severe disorganized thinking or speech may occur during the prodromal and residual periods of schizophrenia.
Grossly disorganized or abnormal motor behavior may manifest itself in a variety of ways,
ranging from childlike "silliness" to unpredictable agitation. Problems may be noted in
any form of goal-directed behavior, leading to difficulties in performing activities of daily
living.
Catatonic behavior is a marked decrease in reactivity to the environment. This ranges
from resistance to instructions {negativism); to maintaining a rigid, inappropriate or bizarre
posture; to a complete lack of verbal and motor responses {mutism and stupor). It can
also include purposeless and excessive motor activity without obvious cause {catatonic
excitement). Other features are repeated stereotyped movements, staring, grimacing,
mutism, and the echoing of speech. Although catatonia has historically been associated
with schizophrenia, catatonic symptoms are nonspecific and may occur in other mental
disorders (e.g., bipolar or depressive disorders with catatonia) and in medical conditions
(catatonic disorder due to another medical condition).
Negative symptoms account for a substantial portion of the morbidity associated with
schizophrenia but are less prominent in other psychotic disorders. Two negative symptoms
are particularly prominent in schizophrenia: diminished emotional expression and
avolition. Diminished emotional expression includes reductions in the expression of emotions
in the face, eye contact, intonation of speech (prosody), and movements of the hand,
head, and face that normally give an emotional emphasis to speech. Avolition is a decrease
in motivated self-initiated purposeful activities. The individual may sit for long periods of
time and show little interest in participating in work or social activities. Other negative
symptoms include alogia, anhedonia, and asociality. Alogia is manifested by diminished
speech output. Anhedonia is the decreased ability to experience pleasure from positive
stimuli or a degradation in the recollection of pleasure previously experienced. Asociality
refers to the apparent lack of interest in social interactions and may be associated with avolition,
but it can also be a manifestation of limited opportunities for social interactions.
Criteria and text for schizotypal personality disorder can be found in the chapter "Personality
Disorders." Because this disorder is considered part of the schizophrenia spectrum of
disorders, and is labeled in this section of ICD-9 and ICD-10 as schizotypal disorder, it is
listed in this chapter and discussed in detail in the DSM-5 chapter "Personality Disorders."
Specify whether:
Erotomanie type: This subtype applies when the central theme of the delusion is that
another person is in love with the individual.
Grandiose type: This subtype applies when the central theme of the delusion is the
conviction of having some great (but unrecognized) talent or insight or having made
some important discovery.
Jeaious type: This subtype applies when the central theme of the individual’s delusion
is that his or her spouse or lover is unfaithful.
Persecutory type: This subtype applies when the central theme of the delusion involves
the individual’s belief that he or she is being conspired against, cheated, spied
on, followed, poisoned or drugged, maliciously maligned, harassed, or obstructed in
the pursuit of long-term goals.
Somatic type: This subtype applies when the central theme of the delusion involves
bodily functions or sensations.
Mixed type: This subtype applies when no one delusional theme predominates.
Unspecified type: This subtype applies when the dominant delusional belief cannot
be clearly determined or is not described in the specific types (e.g., referential delusions
without a prominent persecutory or grandiose component).
In erotomanie type, the central theme of the delusion is that another person is in love with the individual. The person about whom this conviction is held is usually of higher status (e.g., a famous individual or a superior at work) but can be a complete stranger. Efforts to contact the object of the delusion are common. In grandiose type, the central theme of the delusion is the conviction of having some great talent or insight or of having made some important discovery. Less commonly, the individual may have the delusion of having a special relationship with a prominent individual or of being a prominent person (in which case the actual individual may be regarded as an impostor). Grandiose delusions may have a religious content. In jealous type, the central theme of the delusion is that of an unfaithful partner. This belief is arrived at without due cause and is based on incorrect inferences supported by small bits of "evidence" (e.g., disarrayed clothing). The individual with the delusion usually confronts the spouse or lover and attempts to intervene in the imagined infidelity. In persecutory type, the central theme of the delusion involves the individual's belief of being conspired against, cheated, spied on, followed, poisoned, maliciously maligned, harassed, or obstructed in the pursuit of long-term goals. Small slights may be exaggerated and become the focus of a delusional system. The affected individual may engage in repeated attempts to obtain satisfaction by legal or legislative action. Individuals with persecutory delusions are often resentful and angry and may resort to violence against those they believe are hurting them. In somatic type, the central theme of the delusion involves bodily functions or sensations. Somatic delusions can occur in several forms. Most common is the belief that the individual emits a foul odor; that there is an infestation of insects on or in the skin; that there is an internal parasite; that certain parts of the body are misshapen or ugly; or that parts of the body are not functioning.
The essential feature of delusional disorder is the presence of one or more delusions that
persist for at least 1 month (Criterion A). A diagnosis of delusional disorder is not given if
the individual has ever had a symptom presentation that met Criterion A for schizophrenia
(Criterion B). Apart from the direct impact of the delusions, impairments in psychosocial
functioning may be more circumscribed than those seen in other psychotic disorders
such as schizophrenia, and behavior is not obviously bizarre or odd (Criterion C). If mood
episodes occur concurrently with the delusions, the total duration of these mood episodes
is brief relative to the total duration of the delusional periods (Criterion D). The delusions
are not attributable to the physiological effects of a substance (e.g., cocaine) or another
medical condition (e.g., Alzheimer's disease) and are not better explained by another mental
disorder, such as body dysmorphic disorder or obsessive-compulsive disorder (Criterion
E).
In addition to the five symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Social, marital, or work problems can result from the delusional beliefs of delusional disorder. Individuals with delusional disorder may be able to factually describe that others view their beliefs as irrational but are unable to accept this themselves (i.e., there may be "factual insight" but no true insight). Many individuals develop irritable or dysphoric mood, which can usually be understood as a reaction to their delusional beliefs. Anger and violent behavior can occur with persecutory, jealous, and erotomanie types. The individual may engage in htigious or antagonistic behavior (e.g., sending hundreds of letters of protest to the government). Legal difficulties can occur, particularly in jealous and erotomanie types.
The lifetime prevalence of delusional disorder has been estimated at around 0.2%, and the most frequent subtype is persecutory. Delusional disorder, jealous type, is probably more common in males than in females, but there are no major gender differences in the overall frequency of delusional disorder.
On average, global function is generally better than that observed in schizophrenia. Although the diagnosis is generally stable, a proportion of individuals go on to develop schizophrenia. Delusional disorder has a significant familial relationship with both schizophrenia and schizotypal personality disorder. Although it can occur in younger age groups, the condition may be more prevalent in older individuals.
An individual's cultural and religious background must be taken into account in evaluating the possible presence of delusional disorder. The content of delusions also varies across cultural contexts.
The functional impairment is usually more circumscribed than that seen with other psychotic
disorders, although in some cases, the impairment may be substantial and include
poor occupational functioning and social isolation. When poor psychosocial functioning is
present, delusional beliefs themselves often play a significant role. A common characteristic
of individuals with delusional disorder is the apparent normality of their behavior
and appearance when their delusional ideas are not being discussed or acted on.
The essential feature of brief psychotic disorder is a disturbance that involves the sudden
onset of at least one of the following positive psychotic symptoms: delusions, hallucinations,
disorganized speech (e.g., frequent derailment or incoherence), or grossly abnormal
psychomotor behavior, including catatonia (Criterion A). Sudden onset is defined as
change from a nonpsychotic state to a clearly psychotic state within 2 weeks, usually without
a prodrome. An episode of the disturbance lasts at least 1 day but less than 1 month,
and the individual eventually has a full return to the premorbid level of functioning (Criterion
B). The disturbance is not better explained by a depressive or bipolar disorder with
psychotic features, by schizoaffective disorder, or by schizophrenia and is not attributable
to the physiological effects of a substance (e.g., a hallucinogen) or another medical condition
(e.g., subdural hematoma) (Criterion C).
In addition to the five symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Individuals with brief psychotic disorder typically experience emotional turmoil or overwhelming confusion. They may have rapid shifts from one intense affect to another. Although the disturbance is brief, the level of impairment may be severe, and supervision may be required to ensure that nutritional and hygienic needs are met and that the individual is protected from the consequences of poor judgment, cognitive impairment, or acting on the basis of delusions. There appears to be an increased risk of suicidal behavior, particularly during the acute episode.
In the United States, brief psychotic disorder may account for 9% of cases of first-onset psychosis. Psychotic disturbances that meet Criteria A and C, but not Criterion B, for brief psychotic disorder (i.e., duration of active symptoms is 1-6 months as opposed to remission within 1 month) are more common in developing countries than in developed countries. Brief psychotic disorder is twofold more common in females than in males.
Brief psychotic disorder may appear in adolescence or early adulthood, and onset can occur across the lifespan, with the average age at onset being the mid 30s. By definition, a diagnosis of brief psychotic disorder requires a full remission of all symptoms and an eventual full return to the premorbid level of functioning within 1 month of the onset of the disturbance. In some individuals, the duration of psychotic symptoms may be quite brief (e.g., a few days).
It is important to distinguish symptoms of brief psychotic disorder from culturally sanctioned response patterns. For example, in some religious ceremonies, an individual may report hearing voices, but these do not generally persist and are not perceived as abnormal by most members of the individual's community. In addition, cultural and religious background must be taken into account when considering whether beliefs are delusional.
Despite high rates of relapse, for most individuals, outcome is excellent in terms of social
functioning and symptomatology.
The characteristic symptoms of schizophreniform disorder are identical to those of schizophrenia
(Criterion A). Schizophreniform disorder is distinguished by its difference in duration:
the total duration of the illness, including prodromal, active, and residual phases, is
at least 1 month but less than 6 months (Criterion B). The duration requirement for schizophreniform
disorder is intermediate between that for brief psychotic disorder, which lasts
more than 1 day and remits by 1 month, and schizophrenia, which lasts for at least 6 months.
The diagnosis of schizophreniform disorder is made under two conditions. 1) when an episode
of illness lasts between 1 and 6 months and the individual has already recovered,
and 2) when an individual is symptomatic for less than the 6 months' duration required for
the diagnosis of schizophrenia but has not yet recovered. In this case, the diagnosis should
be noted as "schizophreniform disorder (provisional)" because it is uncertain if the individual
will recover from the disturbance within the 6-month period. If the disturbance persists
beyond 6 months, the diagnosis should be changed to schizophrenia.
Another distinguishing feature of schizophreniform disorder is the lack of a criterion
requiring impaired social and occupational functioning. While such impairments may potentially
be present, they are not necessary for a diagnosis of schizophreniform disorder.
In addition to the five symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
As with schizophrenia, currently there are no laboratory or psychometric tests for schizophreniform disorder. There are multiple brain regions where neuroimaging, neuropathological, and neurophysiological research has indicated abnormalities, but none are diagnostic.
Incidence of schizophreniform disorder across sociocultural settings is likely similar to that observed in schizophrenia. In the United States and other developed countries, the incidence is low, possibly fivefold less than that of schizophrenia. In developing countries, the incidence may be higher, especially for the specifier ''with good prognostic features"; in some of these settings schizophreniform disorder may be as common as schizophrenia.
The development of schizophreniform disorder is similar to that of schizophrenia. About one-third of individuals with an initial diagnosis of schizophreniform disorder (provisional) recover within the 6-month period and schizophreniform disorder is their final diagnosis. The majority of the remaining two-thirds of individuals will eventually receive a diagnosis of schizophrenia or schizoaffective disorder.
For the majority of individuals with schizophreniform disorder who eventually receive a
diagnosis of schizophrenia or schizoaffective disorder, the functional consequences are
similar to the consequences of those disorders. Most individuals experience dysfunction in
several areas of daily functioning, such as school or work, interpersonal relationships, and
self-care. Individuals who recover from schizophreniform disorder have better functional
outcomes.
The characteristic symptoms of schizophrenia involve a range of cognitive, behavioral, and
emotional dysfunctions, but no single symptom is pathognomonic of the disorder. The diagnosis
involves the recognition of a constellation of signs and symptoms associated with
impaired occupational or social functioning. Individuals with the disorder will vary substantially
on most features, as schizophrenia is a heterogeneous clinical syndrome.
At least two Criterion A symptoms must be present for a significant portion of time
during a 1-month period or longer. At least one of these symptoms must be the clear presence
of delusions (Criterion Al), hallucinations (Criterion A2), or disorganized speech
(Criterion A3). Grossly disorganized or catatonic behavior (Criterion A4) and negative
symptoms (Criterion A5) may also be present. In those situations in which the activephase
symptoms remit within a month in response to treatment. Criterion A is still met if the
clinician estimates that they would have persisted in the absence of treatment.
Schizophrenia involves impairment in one or more major areas of functioning (Criterion
B). If the disturbance begins in childhood or adolescence, the expected level of function
is not attained. Comparing the individual with unaffected siblings may be helpful. The
dysfunction persists for a substantial period during the course of the disorder and does not
appear to be a direct result of any single feature. Avolition (i.e., reduced drive to pursue
goal-directed behavior; Criterion A5) is linked to the social dysfunction described under
Criterion B. There is also strong evidence for a relationship between cognitive impairment
(see the section "Associated Features Supporting Diagnosis" for this disorder) and functional
impairment in individuals with schizophrenia.
Some signs of the disturbance must persist for a continuous period of at least 6 months
(Criterion C). Pi;odromal symptoms often precede the active phase, and residual symptoms
may follow it, characterized by mild or subthreshold forms of hallucinations or
delusions. Individuals may express a variety of unusual or odd beliefs that are not of delusional
proportions (e.g., ideas of reference or magical thinking); they may have unusual
perceptual experiences (e.g., sensing the presence of an unseen person); their speech may
be generally understandable but vague; and their behavior may be unusual but not grossly
disorganized (e.g., mumbling in public). Negative symptoms are common in the prodromal
and residual phases and can be severe. Individuals who had been socially active
may become withdrawn from previous routines. Such behaviors are often the first sign of
a disorder.
Mood symptoms and full mood episodes are common in schizophrenia and may be concurrent
with active-phase symptomatology. However, as distinct from a psychotic mood disorder,
a schizophrenia diagnosis requires the presence of delusions or hallucinations in the
absence of mood episodes. In addition, mood episodes, taken in total, should be present for
only a minority of the total duration of the active and residual periods of the illness.
In addition to the five symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Individuals with schizophrenia may display inappropriate affect (e.g., laughing in the absence
of an appropriate stimulus); a dysphoric mood that can take the form of depression,
anxiety, or anger; a disturbed sleep pattern (e.g., daytime sleeping and nighttime activity);
and a lack of interest in eating or food refusal. Depersonalization, derealization, and somatic
concerns may occur and sometimes reach delusional proportions. Anxiety and phobias
are common. Cognitive deficits in schizophrenia are conrmion and are strongly linked
to vocational and functional impairments. These deficits can include decrements in declarative
memory, working memory, language function, and other executive functions, as well
as slower processing speed. Abnormalities in sensory processing and inhibitory capacity,
as well as reductions in attention, are also found. Some individuals with schizophrenia
show social cognition deficits, including deficits in the ability to infer the intentions of
other people (theory of mind), and may attend to and then inteφret irrelevant events or
stimuli as meaningful, perhaps leading to the generation of explanatory delusions. These
impairments frequently persist during symptomatic remission.
Some individuals with psychosis may lack insight or awareness of their disorder (i.e.,
anosognosia). This lack of "'insight" includes unawareness of symptoms of schizophrenia
and may be present throughout the entire course of the illness. Unawareness of illness is
typically a symptom of schizophrenia itself rather than a coping strategy. It is comparable
to the lack of awareness of neurological deficits following brain damage, termed anosognosia.
This symptom is the most common predictor of non-adherence to treatment, and it
predicts higher relapse rates, increased number of involuntary treatments, poorer psychosocial
functioning, aggression, and a poorer course of illness.
Hostility and aggression can be associated with schizophrenia, although spontaneous
or random assault is uncommon. Aggression is more frequent for younger males and for
individuals with a past history of violence, non-adherence with treatment, substance
abuse, and impulsivity. It should be noted that the vast majority of persons with schizophrenia
are not aggressive and are more frequently victimized than are individuals in the
general population.
Currently, there are no radiological, laboratory, or psychometric tests for the disorder.
Differences are evident in multiple brain regions between groups of healthy individuals
and persons with schizophrenia, including evidence from neuroimaging, neuropathological,
and neurophysiological studies. Differences are also evident in cellular architecture,
white matter connectivity, and gray matter volume in a variety of regions such as the prefrontal
and temporal cortices. Reduced overall brain volume has been observed, as well as
increased brain volume reduction with age. Brain volume reductions with age are more
pronounced in individuals with schizophrenia than in healthy individuals. Finally, individuals
with schizophrenia appear to differ from individuals without the disorder in eyetracking
and electrophysiological indices.
Neurological soft signs common in individuals with schizophrenia include impairments
in motor coordination, sensory integration, and motor sequencing of complex movements;
left-right confusion; and disinhibition of associated movements. In addition, minor physical
anomalies of the face and limbs may occur.
The lifetime prevalence of schizophrenia appears to be approximately 0.3%-0.7%, although there is reported variation by race/ethnicity, across countries, and by geographic origin for immigrants and children of immigrants. The sex ratio differs across samples and populations: for example, an emphasis on negative symptoms and longer duration of disorder (associated with poorer outcome) shows higher incidence rates for males, whereas definitions allowing for the inclusion of more mood symptoms and brief presentations (associated with better outcome) show equivalent risks for both sexes.
Cultural and socioeconomic factors must be considered, particularly when the individual and the clinician do not share the same cultural and socioeconomic background. Ideas that appear to be delusional in one culture (e.g., witchcraft) may be commonly held in another. In some cultures, visual or auditory hallucinations with a religious content (e.g., hearing God's voice) are a normal part of religious experience. In addition, the assessment of disorganized speech may be made difficult by linguistic variation in narrative styles across cultures. The assessment of affect requires sensitivity to differences in styles of emotional expression, eye contact, and body language, which vary across cultures. If the assessment is conducted in a language that is different from the individual's primary language, care must be taken to ensure that alogia is not related to linguistic barriers. In certain cultures, distress may take the form of hallucinations or pseudo-hallucinations and overvalued ideas that may present clinically similar to true psychosis but are normative to the patient's subgroup.
A number of features distinguish the clinical expression of schizophrenia in females and males. The general incidence of schizophrenia tends to be slightly lower in females, particularly among treated cases. The age at onset is later in females, with a second mid-life peak as described earlier (see the section "Development and Course" for this disorder). Symptoms tend to be more affect-laden among females, and there are more psychotic symptoms, as well as a greater propensity for psychotic symptoms to worsen in later life. Other symptom differences include less frequent negative symptoms and disorganization. Finally, social functioning tends to remain better preserved in females. There are, however, frequent exceptions to these general caveats.
Approximately 5%-6% of individuals with schizophrenia die by suicide, about 20% attempt suicide on one or more occasions, and many more have significant suicidal ideation. Suicidal behavior is sometimes in response to command hallucinations to harm oneself or others. Suicide risk remains high over the whole lifespan for males and females, although it may be especially high for younger males with comorbid substance use. Other risk factors include having depressive symptoms or feelings of hopelessness and being unemployed, and the risk is higher, also, in the period after a psychotic episode or hospital discharge.
Schizophrenia is associated with significant social and occupational dysfunction. Making educational progress and maintaining employment are frequently impaired by avolition or other disorder manifestations, even when the cognitive skills are sufficient for the tasks at hand. Most individuals are employed at a lower level than their parents, and most, particularly men, do not marry or have limited social contacts outside of their family.
The diagnosis of schizoaffective disorder is based on the assessment of an uninterrupted
period of illness during which the individual continues to display active or residual symptoms
of psychotic illness. The diagnosis is usually, but not necessarily, made during the
period of psychotic illness. At some time during the period. Criterion A for schizophrenia
has to be met. Criteria B (social dysfunction) and F (exclusion of autism spectrum disorder
or other commimication disorder of childhood onset) for schizophrenia do not have to be
met. In addition to meeting Criterion A for schizophrenia, there is a major mood episode
(major depressive or manic) (Criterion A for schizoaffective disorder). Because loss of interest
or pleasure is common in schizophrenia, to meet Criterion A for schizoaffective disorder,
the major depressive episode must include pervasive depressed mood (i.e., the
presence of markedly diminished interest or pleasure is not sufficient). Episodes of depression
or mania are present for the majority of the total duration of the illness (i.e., after
Criterion A has been met) (Criterion C for schizoaffective disorder). To separate schizoaffective
disorder from a depressive or bipolar disorder with psychotic features, delusions
or hallucinations must be present for at least 2 w^eeks in the absence of a major mood episode
(depressive or manic) at some point during the lifetime duration of the illness (Criterion
B for schizoaffective disorder). The symptoms must not be attributable to the effects
of a substance or another medical condition (Criterion D for schizoaffective disorder).
Criterion C for schizoaffective disorder specifies that mood symptoms meeting criteria
for a major mood episode must be present for the majority of the total duration of the active
and residual portion of the illness. Criterion C requires the assessment of mood symptoms
for the entire course of a psychotic illness, which differs from the criterion in DSM-IV,
which required only an assessment of the current period of illness. If the mood symptoms
are present for only a relatively brief period, the diagnosis is schizophrenia, not schizoaffective
disorder. When deciding whether an individual's presentation meets Criterion C,
the clinician should review the total duration of psychotic illness (i.e., both active and residual
symptoms) and determine when significant mood symptoms (untreated or in need
of treatment with antidepressant and/or mood-stabilizing medication) accompanied the
psychotic symptoms. This determination requires sufficient historical information and
clinical judgment. For example, an individual with a 4-year history of active and residual
symptoms of schizophrenia develops depressive and manic episodes that, taken together,
do not occupy more than 1 year during the 4-year history of psychotic illness. This presentation
would not meet Criterion C.
In addition to the five symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Occupational functioning is frequently impaired, but this is not a defining criterion (in contrast to schizophrenia). Restricted social contact and difficulties with self-care are associated with schizoaffective disorder, but negative symptoms may be less severe and less persistent than those seen in schizophrenia. Anosognosia (i.e., poor insight) is also common in schizoaffective disorder, but the deficits in insight may be less severe and pervasive than those in schizophrenia. Individuals with schizoaffective disorder may be at increased risk for later developing episodes of major depressive disorder or bipolar disorder if mood symptoms continue following the remission of symptoms meeting Criterion A for schizophrenia. There may be associated alcohol and other substance-related disorders. There are no tests or biological measures that can assist in making the diagnosis of schizoaffective disorder. Whether schizoaffective disorder differs from schizophrenia with regard to associated features such as structural or functional brain abnormalities, cognitive deficits, or genetic risk factors is not clear.
Schizoaffective disorder appears to be about one-third as common as schizophrenia. Lifetime prevalence of schizoaffective disorder is estimated to be 0.3%. The incidence of schizoaffective disorder is higher in females than in males, mainly due to an increased incidence of the depressive type among females.
Cultural and socioeconomic factors must be considered, particularly when the individual and the clinician do not share the same cultural and economic background. Ideas that appear to be delusional in one culture (e.g., witchcraft) may be commonly held in another. There is also some evidence in the literature for the overdiagnosis of schizophrenia compared with schizoaffective disorder in African American and Hispanic populations, so care must be tal^en to ensure a culturally appropriate evaluation that includes both psychotic and affective symptoms.
The lifetime risk of suicide for schizophrenia and schizoaffective disorder is 5%, and the presence of depressive symptoms is correlated w^ith a higher risk for suicide. There is evidence that suicide rates are higher in North American populations than in European, Eastern European, South American, and Indian populations of individuals with schizophrenia or schizoaffective disorder.
Schizoaffective disorder is associated with social and occupational dysfunction, but dysfunction is not a diagnostic criterion (as it is for schizophrenia), and there is substantial variability between individuals diagnosed with schizoaffective disorder.
Many individuals diagnosed with schizoaffective disorder are also diagnosed with other
mental disorders, especially substance use disorders and anxiety disorders. Similarly, the
incidence of medical conditions is increased above base rate for the general population
and leads to decreased life expectancy.
The essential features of substance/medication-induced psychotic disorder are prominent
delusions and/or hallucinations (Criterion A) that are judged to be due to the physiological
effects of a substance/medication (i.e., a drug of abuse, a medication, or a toxin exposure)
(Criterion B). Hallucinations that the individual realizes are substance/medicationinduced
are not included here and instead would be diagnosed as substance intoxication
or substance withdrawal with the accompanying specifier "with perceptual disturbances"
(applies to alcohpl withdrawal; cannabis intoxication; sedative, hypnotic, or anxiolytic
withdrawal; and stimulant intoxication).
A substance/medication-induced psychotic disorder is distinguished from a primary
psychotic disorder by considering the onset, course, and other factors. For drugs of abuse,
there must be evidence from the history, physical examination, or laboratory findings of
substance use, intoxication, or withdrawal. Substance/medication-induced psychotic
disorders arise during or soon after exposure to a medication or after substance intoxication
or withdrawal but can persist for weeks, whereas primary psychotic disorders may
precede the onset of substance/medication use or may occur during times of sustained abstinence.
Once initiated, the psychotic symptoms may continue as long as the substance/
medication use continues. Another consideration is the presence of features that are atypical
of a primary psychotic disorder (e.g., atypical age at onset or course). For example, the
appearance of delusions de novo in a person older than 35 years without a known history
of a primary psychotic disorder should suggest the possibility of a substance/medicationinduced
psychotic disorder. Even a prior history of a primary psychotic disorder does not
rule out the possibility of a substance/medication-induced psychotic disorder. In contrast,
factors that suggest that the psychotic symptoms are better accounted for by a primary
psychotic disorder include persistence of psychotic symptoms for a substantial period of
time (i.e., a month or more) after the end of substance intoxication or acute substance withdrawal
or after cessation of medication use; or a history of prior recurrent primary psychotic
disorders. Other causes of psychotic symptoms must be considered even in an
individual with substance intoxication or withdrawal, because substance use problems are
not uncommon among individuals with non-substance/medication-induced psychotic
disorders.
In addition to the four symptom domain areas identified in the diagnostic criteria, the
assessment of cognition, depression, and mania symptom domains is vital for making critically
important distinctions between the various schizophrenia spectrum and other psychotic
disorders.
Psychotic disorders can occur in association with intoxication with the following classes of
substances: alcohol; cannabis; hallucinogens, including phencyclidine and related substances;
inhalants; sedatives, hypnotics, and anxiolytics; stimulants (including cocaine);
and other (or unknown) substances. Psychotic disorders can occur in association with withdrawal
from the following classes of substances: alcohol; sedatives, hypnotics, and anxiolytics;
and other (or unknown) substances.
Some of the medications reported to evoke psychotic symptoms include anesthetics
and analgesics, anticholinergic agents, anticonvulsants, antihistamines, antihypertensive
and cardiovascular medications, antimicrobial medications, antiparkinsonian medications,
chemotherapeutic agents (e.g., cyclosporine, procarbazine), corticosteroids, gastrointestinal
medications, muscle relaxants, nonsteroidal anti-inflammatory medications,
other over-the-counter medications (e.g., phenylephrine, pseudoephedrine), antidepressant
medication, and disulfiram. Toxins reported to induce psychotic symptoms include
anticholinesterase, organophosphate insecticides, sarin and other nerve gases, carbon
monoxide, carbon dioxide, and volatile substances such as fuel or paint.
Prevalence of substance/medication-induced psychotic disorder in the general population is unknown. Between 7% and 25% of individuals presenting with a first episode of psychosis in different settings are reported to have substance/medication-induced psychotic disorder.
Substance/medication-induced psychotic disorder is typically severely disabling and
consequently is observed most frequently in emergency rooms, as individuals are often
brought to the acute-care setting when it occurs. However, the disability is typically selflimited
and resolves upon removal of the offending agent.
The essential features of psychotic disorder due to another medical condition are prominent
delusions or hallucinations that are judged to be attributable to the physiological effects
of another medical condition and are not better explained by another mental disorder
(e.g., the symptoms are not a psychologically mediated response to a severe medical condition,
in which case a diagnosis of brief psychotic disorder, with marked stressor, would
be appropriate).
Hallucinations can occur in any sensory modality (i.e., visual, olfactory, gustatory, tactile,
or auditory), but certain etiological factors are likely to evoke specific hallucinatory
phenomena. Olfactory hallucinations are suggestive of temporal lobe epilepsy. Hallucinations
may vary from simple and unformed to highly complex and organized, depending
on etiological and environmental factors. Psychotic disorder due to another medical condition
is generally not diagnosed if the individual maintains reality testing for the hallucinations
and appreciates that they result from the medical condition. Delusions may have
a variety of themes, including somatic, grandiose, religious, and, most commonly, persecutory.
On the whole, however, associations between delusions and particular medical
conditions appear to be less specific than is the case for hallucinations.
In determining whether the psychotic disturbance is attributable to another medical
condition, the presence of a medical condition must be identified and considered to be the
etiology of the psychosis through a physiological mechanism. Although there are no
infallible guidelines for determining whether the relationship between the psychotic disturbance
and the medical condition is etiological, several considerations provide some guidance.
One consideration is the presence of a temporal association between the onset, exacerbation,
or remission of the medical condition and that of the psychotic disturbance. A second
consideration is the presence of features that are atypical for a psychotic disorder (e.g.,
atypical age at onset or presence of visual or olfactory hallucinations). The disturbance must
also be distinguished from a substance/medication-induced psychotic disorder or another
mental disorder (e.g., an adjustment disorder).
The temporal association of the onset or exacerbation of the medical condition offers the greatest diagnostic certainty that the delusions or hallucinations are attributable to a medical condition. Additional factors may include concomitant treatments for the underlying medical condition that confer a risk for psychosis independently, such as steroid treatment for autoimmune disorders.
Prevalence rates for psychotic disorder due to another medical condition are difficult to estimate given the wide variety of underlying medical etiologies. Lifetime prevalence has been estimated to range from 0.21% to 0.54%. When the prevalence findings are stratified by age group, individuals older than 65 years have a significantly greater prevalence of 0.74% compared with those in younger age groups. Rates of psychosis also vary according to the underlying medical condition; conditions most commonly associated with psychosis include untreated endocrine and metabolic disorders, autoimmune disorders (e.g., systemic lupus erythematosus, N-methyl-D-aspartate (NMDA) receptor autoimmune encephalitis), or temporal lobe epilepsy. Psychosis due to epilepsy has been further differentiated into ictal, postictal, and interictal psychosis. The most common of these is postictal psychosis, observed in 2%-7.8% of epilepsy patients. Among older individuals, there may be a higher prevalence of the disorder in females, although additional gender-related features are not clear and vary considerably with the gender distributions of the underlying medical conditions.
Suicide risk in the context of psychotic disorder due to another medical condition is not clearly delineated, although certain conditions such as epilepsy and multiple sclerosis are associated with increased rates of suicide, which may be further increased in the presence of psychosis.
Functional disability is typically severe in the context of psychotic disorder due to another
medical condition but will vary considerably by the type of condition and likely improve
with successful resolution of the condition.
Catatonia associated with another mental disorder (catatonia specifier) may be used when
criteria are met for catatonia during the course of a neurodevelopmental, psychotic, bipolar,
depressive, or other mental disorder. The catatonia specifier is appropriate when the
clinical picture is characterized by marked psychomotor disturbance and involves at least
three of the 12 diagnostic features listed in Criterion A. Catatonia is typically diagnosed in
an inpatient setting and occurs in up to 35% of individuals with schizophrenia, but the majority
of catatonia cases involve individuals with depressive or bipolar disorders. Before
the catatonia specifier is used in neurodevelopmental, psychotic, bipolar, depressive, or
other mental disorders, a wide variety of other medical conditions need to be ruled out;
these conditions include, but are not limited to, medical conditions due to infectious, metabolic,
or neurological conditions (see '"Catatonic Disorder Due to Another Medical Condition").
Catatonia can also be a side effect of a medication (see the chapter "Medication-
Induced Movement Disorders and Other Adverse Effects of Medication"). Because of the
seriousness of the complications, particular attention should be paid to the possibility that
the catatonia is attributable to 333.92 (G21.0) neuroleptic malignant syndrome.
The essential feature of catatonic disorder due to another medical condition is the presence of catatonia that is judged to be attributed to the physiological effects of another medical condition. Catatonia can be diagnosed by the presence of at least three of the 12 clinical features in Criterion A. There must be evidence from the history, physical examination, or laboratory findings that the catatonia is attributable to another medical condition (Criterion B). The diagnosis is not given if the catatonia is better explained by another mental disorder (e.g., manic episode) (Criterion C) or if it occurs exclusively during the course of a delirium (Criterion D).
A variety of medical conditions may cause catatonia, especially neurological conditions (e.g., neoplasms, head trauma, cerebrovascular disease, encephalitis) and metabolic conditions (e.g., hypercalcemia, hepatic encephalopathy, homocystinuria, diabetic ketoacidosis). The associated physical examination findings, laboratory findings, and patterns of prevalence and onset reflect those of the etiological medical condition.