Schizophrenia and Related Disorders: ICD-10 Specifications
Schizophrenia
Diagnostic Criteria
Criterion A: Two or more of the following symptoms for at least one month:
- Delusions (erroneous beliefs, sometimes misinterpretations of experiences, expressing loss of control over mind/body)
- Hallucinations (auditory, visual, olfactory, gustatory, tactile)
- Disorganized speech (losing train of thought, jumping between topics)
- Grossly disorganized or catatonic behavior
- Negative symptoms:
- Affective flattening (lack of expression, poor eye contact, reduced body language)
- Alogia (poverty of speech)
- Abulia (inability to initiate/continue activities)
Criterion B: Dysfunction in one or more major areas (interpersonal relationships, work, study, personal care).
Criterion C: Continuous signs of disturbance for at least six months, with one month meeting Criterion A.
Criterion D: No major depressive, manic, or mixed episodes during the residual period.
Criterion E: Not due to substance use or medical condition.
Criterion F: Only if prominent delusions or hallucinations are present for one month.
Symptoms
Positive Symptoms: Excess or distortion of normal functions (delusions, hallucinations, disorganized speech, disorganized/catatonic behavior).
Negative Symptoms: Decrease or loss of normal functions (affective flattening, apathy, alogia).
Other Symptoms: Inappropriate affect, anhedonia, dysphoric mood, difficulty concentrating, confusion, disorganization, memory impairment.
Associated Disorders and Risk Factors
Suicide risk (10%), male gender, under 30, depressive symptoms, unemployment, recent hospital discharge.
Course and Specifiers
- Episodic with residual symptoms
- With prominent negative symptoms
- Episodic with no residual symptoms
- Continuous
- Episodic in partial remission
- Episodic in complete remission
- Other pattern not specified
- Less than one year since first active phase symptoms
Structural brain abnormalities, poor coordination, slowed reaction times, nicotine dependence.
Subtypes
Paranoid Type
Criterion: Preoccupation with delusions or frequent auditory hallucinations.
Criterion B: No disorganized speech, behavior, or flat/inappropriate affect.
Associated Symptoms: Anxiety, anger, withdrawal, argumentativeness.
Disorganized Type
Criterion: Disorganized speech, behavior, and flat/inappropriate affect.
Criterion B: Does not meet criteria for Catatonic Type.
Catatonic Type
Two or more of the following:
- Motor immobility (catalepsy, stupor)
- Excessive motor activity
- Extreme negativism or mutism
- Peculiarities of voluntary movement (bizarre posturing)
- Echolalia or echopraxia
Undifferentiated Type
Meets criteria for schizophrenia but not for Paranoid, Disorganized, or Catatonic types.
Residual Type
Past episode of schizophrenia but no current active symptoms.
Criterion: Absence of positive symptoms.
Criterion B: Continuing evidence of disturbance (negative symptoms or attenuated positive symptoms).
Schizophreniform Disorder
Similar to schizophrenia but shorter duration (1-6 months).
Schizoaffective Disorder
Mood episode concurrent with Criterion A of schizophrenia.
Delusions or hallucinations for at least two weeks without mood symptoms.
Delusional Disorder
Non-bizarre delusions for at least one month.
Brief Psychotic Disorder
Psychotic symptoms lasting 1 day to 1 month.
Shared Psychotic Disorder
Delusion develops in context of close relationship with someone who has an established delusion.
Psychotic Disorder Due to a General Medical Condition
Psychosis directly caused by a medical condition.
Substance-Induced Psychotic Disorder
Psychosis caused by substance use.
Psychotic Disorder NOS
Used when there is insufficient information for a specific diagnosis.