Schizophrenia: DSM-5 Definition
Schizophrenia is a severe and chronic mental disorder characterized by disturbances in thought, perception and behavior
By Katie Hurley, LCSW
Schizophrenia involves a range of cognitive, behavioral, and emotional symptoms, and it can be difficult to diagnose. There’s no simple physical or lab test for schizophrenia, and diagnosis involves the recognition of a constellation of symptoms negatively impacting social or occupational functioning.
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5), the lifetime prevalence of schizophrenia is approximately 0.3%-0.7%. The psychotic features of the disorder typically emerge between the mid-teens and mid-thirties, with the peak age of onset of the first psychotic episode in the early to mid-twenties for males and late twenties for females.
Diagnosis
The DSM 5 outlines the following criterion to make a diagnosis of schizophrenia:
Two or more of the following for at least a one-month (or longer) period of time, and at least one of them must be 1, 2, or 3:
Delusions
Hallucinations
Disorganized speech
Grossly disorganized or catatonic behavior
Negative symptoms, such as diminished emotional expression
Impairment in one of the major areas of functioning for a significant period of time since the onset of the disturbance: Work, interpersonal relations, or self-care.
Some signs of the disorder must last for a continuous period of at least 6 months. This six-month period must include at least one month of symptoms (or less if treated) that meet criterion A (active phase symptoms) and may include periods of residual symptoms. During residual periods, only negative symptoms may be present.
Schizoaffective disorder and bipolar or depressive disorder with psychotic features have been ruled out:
No major depressive or manic episodes occurred concurrently with active phase symptoms
If mood episodes (depressive or manic) have occurred during active phase symptoms, they have been present for a minority of the total duration of the active and residual phases of the illness.
The disturbance is not caused by the effects of a substance or another medical condition
If there is a history of autism spectrum disorder or a communication disorder (childhood onset), the diagnosis of schizophrenia is only made if prominent delusions or hallucinations, along with other symptoms, are present for at least one month
Associated Features
There are a number of symptoms that contribute to a diagnosis of schizophrenia.
Inappropriate affect (laughing in the absence of a stimulus)
Disturbed sleep pattern
Dysphoric mood (can be depression, anxiety, or anger)
Anxiety and phobias
Depersonalization (detachment or feeling of disconnect from self)
Derealization (a feeling that surrounding aren’t real)
Cognitive deficits impacting language, processing, executive function, and/or memory
Lack of insight into disorder
Social cognition deficits
Hostility and aggression
Cognitive impairments caused by the disorder may persist when other symptoms are in remission. This contributes to impairments in functioning in employment, interpersonal relationships, and the ability to engage in proper self-care.
Suicide risk
5%-6% of people with schizophrenia die by suicide, about 20% make suicide attempts on more than one occasion, and many more have significant suicidal thoughts. Suicidal behavior can be in response to hallucinations and suicide risk remains high over the lifespan of individuals with schizophrenia.
Functional consequences
Schizophrenia is associated with social and occupational dysfunction. Completing education and maintaining employment are negatively impacted by symptoms of the illness, and most individuals diagnosed with schizophrenia are employed at a lower level than their parents. Many have few or limited social relationships outside of their immediate family.