Acute and transient psychotic disorder

Essential (Required) Features:

• Acute onset of psychotic symptoms, which can include delusions, hallucinations, disorganized thinking, or experiences of influence, passivity or control, that emerge without a prodrome, progressing from a non-psychotic state to a clearly psychotic state within 2 weeks. Psychomotor disturbances may also be present, including catatonia.
• Symptoms change rapidly, both in nature and intensity. Such changes may occur from day to day, or even within a single day.
• Absence of negative symptoms (i.e., affective flattening, alogia or paucity of speech, avolition, asociality, anhedonia) during the psychotic episode.
• The duration of the symptoms does not exceed 3 months, and most commonly lasts from a few days to 1 month.
• The symptoms or behaviours are not a manifestation of another medical condition (e.g., a brain tumour), are not due to the effects of a substance or medication on the central nervous system (e.g., corticosteroids), including withdrawal effects (e.g., from alcohol), and are not better accounted for by Schizophrenia or Other Primary Psychotic Disorder.

Course specifiers for Acute and Transient Psychotic Disorder:

The following specifiers should be applied to identify the course of Acute and Transient Psychotic Disorder, including whether the individual currently meets the diagnostic requirements for the disorder or is in partial or full remission. If there have been no previous episodes of Acute and Transient Psychotic Disorder, the corresponding single episode specifier should be applied. If there have been multiple such episodes, the corresponding multiple episodes specifiers should be applied.

6A23.0 Acute and Transient Psychotic Disorder, first episode

• The first episode specifier should be applied when the current or most recent episode is the first manifestation of Acute and Transient Psychotic Disorder meeting all diagnostic requirements of the disorder.

#### 6A23.00 Acute and Transient Psychotic Disorder, first episode, currently symptomatic

• All diagnostic requirements for Acute and Transient Psychotic Disorder in terms of symptoms and duration are currently met, or have been met within the past 1 month.
• There have been no previous episodes of Acute and Transient Psychotic Disorder.

#### 6A23.01 Acute and Transient Psychotic Disorder, first episode, in partial remission

• The full diagnostic requirements for Acute and Transient Psychotic Disorder have not been met within the past month, but some clinically significant symptoms remain, which may or may not be associated with functional impairment.
• There have been no previous episodes of Acute and Transient Psychotic Disorder.

Note: This category may also be used to designate the re-emergence of subthreshold symptoms of Acute and Transient Psychotic Disorder following an asymptomatic period in a person who has previously met the diagnostic requirements for Acute and Transient Psychotic Disorder.

#### 6A23.02 Acute and Transient Psychotic Disorder, first episode, in full remission

• The full diagnostic requirements for Acute and Transient Psychotic Disorder have not been met within the past month, and no clinically significant symptoms remain.
• There have been no previous episodes of Acute and Transient Psychotic Disorder.

#### 6A23.0Z Acute and Transient Psychotic Disorder, first episode, unspecified

6A23.1 Acute and Transient Psychotic Disorder, multiple episodes

• The multiple episodes specifier should be applied when there has been a minimum of two episodes meeting all diagnostic requirements of Acute and Transient Psychotic Disorder in terms of symptoms and duration, with a period of full remission between episodes lasting at least 3 months.

#### 6A23.10 Acute and Transient Psychotic Disorder, multiple episodes, currently symptomatic

• All diagnostic requirements for Acute and Transient Psychotic Disorder in terms of symptoms and duration are currently met, or have been met within the past 1 month.
• There has been a minimum of two episodes, with a period of full remission between episodes lasting at least 3 months.

#### 6A23.11 Acute and Transient Psychotic Disorder, multiple episodes, in partial remission

• The full diagnostic requirements for Acute and Transient Psychotic Disorder have not been met within the past month, but some clinically significant symptoms remain, which may or may not be associated with functional impairment.
• There has been a minimum of two episodes, with a period full remission between episodes lasting at least 3 months.

Note: This category may also be used to designate the re-emergence of subthreshold symptoms of Acute and Transient Psychotic Disorder following an asymptomatic period.

#### 6A23.12 Acute and Transient Psychotic Disorder, multiple episodes, in full remission

• The full diagnostic requirements for Acute and Transient Psychotic Disorder have not been met within the past month, and no clinically significant symptoms remain.
• There has been a minimum of two episodes, with a period of full remission between episodes lasting at least 3 months.

#### 6A23.1Z Acute and Transient Psychotic Disorder, multiple episodes, unspecified

6A23.Y Other Specified Acute and Transient Psychotic Disorder

6A23.Z Acute and Transient Psychotic Disorder, Unspecified

Additional Clinical Features:

• The onset of the disorder is usually associated with a rapid deterioration in social and occupational functioning. Following remission, the person is generally able to regain the premorbid level of functioning.
• There are often other symptoms such as fluctuating disturbances of mood and affect, transient states of perplexity or confusion, or impairment of attention and concentration.
• An episode of acute stress preceding the onset of Acute and Transient Psychotic Disorder is commonly reported, but this is not a diagnostic requirement.
• If the symptoms last for more than 3 months, a different diagnosis should be considered, depending on the specific symptoms (e.g., Schizophrenia, Schizoaffective Disorder, Delusional Disorder, Other Primary Psychotic Disorder).

Boundary with Normality (Threshold):

• Isolated unusual subjective experiences, such as experiences resembling hallucinations and delusions, are reported in the general population. However, in Acute and Transient Psychotic Disorder, the symptoms rapidly progress to full psychosis, they are usually polymorphic, fluctuating in quality and intensity (e.g., having features come and go in relatively rapid succession, or having the nature of a feature change over time, such as the focus or nature of a delusional belief), and usually fully remit within several weeks.

Course Features:

• Symptoms are brief in nature lasting anywhere from a few days but not exceeding 3 months.
• Some individuals diagnosed with Acute and Transient Psychotic Disorder will go on to meet diagnostic requirements for another mental disorder, such as Schizophrenia, another Primary Psychotic Disorder, or a Mood Disorder.
• In general, favourable outcomes are associated with acute onset, short duration, good premorbid functioning, and female gender.

Developmental Presentations:

• Onset of Acute and Transient Psychotic Disorders typically occurs between early and middle adulthood. However, the disorder may occur during adolescence or later in the lifespan often following an episode of acute stress.

Culture-Related Features:

• Migrant populations may be more likely to report these experiences. This may be due to higher prevalence as a result of migration-related stress, misattribution of psychosis by clinicians unfamiliar with cultural expressions of distress, or a combination of the two.
• In some cultures, distress due to social and other environmental circumstances may be expressed in ways that can be misinterpreted as psychotic symptoms (e.g., overvalued ideas and pseudo-hallucinations) but that instead are normative to the person’s subgroup.

Sex- and/or Gender-Related Features:

• Acute and Transient Psychotic Disorder is more common in females.
• Male gender and younger age of Acute and Transient Psychotic Disorder onset appear to be associated with greater risk of subsequent development of Schizophrenia.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Schizophrenia and Schizoaffective Disorder: The psychotic symptoms in Schizophrenia and in Schizoaffective Disorder last for at least 1 month in their full, florid form and tend to be more stable or fixed (e.g., having the same delusion for a period of months). In contrast, the symptoms in Acute and Transient Psychotic Disorder tend to fluctuate rapidly in intensity and type across time, such that the content and focus of delusions or hallucinations often shift, even on a daily basis. Negative symptoms may be present in Schizophrenia and Schizoaffective Disorder, but do not occur in Acute and Transient Psychotic Disorder. The duration of Acute and Transient Psychotic Disorder does not exceed 3 months, and most often lasts from a few days to 1 month, as compared to a much longer typical course for Schizophrenia or Schizoaffective Disorder. Finally, in contrast to Schizophrenia where the onset is often preceded by a history of poor premorbid adjustment, in Acute and Transient Psychotic Disorder the person’s symptoms progress rapidly without a prodromal period. In cases that meet both the diagnostic requirements for Acute and Transient Psychotic Disorder (i.e., fluctuating symptoms, acute onset, duration less than 3 months) and Schizophrenia (e.g., delusions and hallucinations for more than 1 month) in the absence of a previous history of Schizophrenia, a diagnosis of Acute and Transient Psychotic Disorder and not Schizophrenia should be assigned.
• Boundary with Mood Disorders with psychotic symptoms: Depressive and Bipolar Disorders are characterized by a predominant disturbance in mood that persists for at least several days and often much longer. Although mood symptoms may occur in Acute and Transient Psychotic Disorder, they are transient and do not meet the required duration or associated symptoms to qualify for a Depressive, Manic, or Mixed Episode.
• Boundary with Acute Stress Reaction and Dissociative Disorders: Like Acute and Transient Psychotic Disorder, Acute Stress Reaction and some Dissociative Disorders have an acute onset, often in response to a stressful life experience, and resolve in days to weeks. In contrast, by definition, Acute and Transient Psychotic Disorder includes psychotic symptoms like hallucinations or delusions that do not occur in Disorders Specifically Associated with Stress or in Dissociative Disorders.
• Boundary with Delirium: In Delirium, the individual has a fluctuating clouding of consciousness (i.e., reduced ability to direct, focus, sustain, and shift attention) and awareness (i.e., reduced orientation to the environment). In contrast, in Acute and Transient Psychotic Disorder, the person maintains a regular level of alertness and relatively clear sense of consciousness, despite transient states of perplexity, confusion, and impairment of attention or concentration.