A 23-year-old man is brought to the clinic by his parents due to concerning behavior over the past 8 months. They report that he has become increasingly withdrawn and often mutters to himself. He frequently avoids social interaction and spends most of his time in his room. He states that he believes that the government has installed cameras in his home to monitor his activities. He reports hearing voices that tell him he is being watched. He has no prior psychiatric history and does not take any medications. He does not use alcohol or illicit drugs. Family history is notable for an uncle with schizophrenia. Vital signs are within normal limits. On physical examination, he is disheveled, exhibits a flat affect, and appears internally preoccupied. Neurologic examination is unremarkable.
D) Schizophrenia
According to the DSM-5, schizophrenia is diagnosed when the following criteria are met:
- Two or more of the following symptoms, each present for a significant portion of time during a 1-month period (or less if successfully treated). At least one symptom must be from the first three:
- Delusions
- Hallucinations
- Disorganized speech
- Grossly disorganized or catatonic behavior
- Negative symptoms (e.g., diminished emotional expression, avolition)
- Functional decline in one or more major areas (e.g., work, interpersonal relationships, self-care).
- Continuous signs of disturbance for at least 6 months, which must include at least 1 month of active-phase symptoms (criterion A), with periods of prodromal or residual symptoms (e.g., social withdrawal, flat affect).
This patient has positive symptoms (delusions of surveillance, auditory hallucinations); negative symptoms (flat affect, social withdrawal); functional decline (isolation, disheveled appearance), and a symptom duration of 8 months, meeting the time criterion.
Answer choice A: Brief psychotic disorder, is incorrect. Brief psychotic disorder is characterized by the sudden onset of psychotic symptoms (e.g., delusions, hallucinations, or disorganized speech/behavior) that last at least 1 day but less than 1 month, with eventual full return to premorbid functioning. It is often triggered by a stressor (e.g., trauma or loss). This patient's symptoms have persisted for 8 months, far exceeding the brief duration required for this diagnosis.
Answer choice B: Delusional disorder, is incorrect. Delusional disorder involves one or more delusions lasting ≥1 month, without other psychotic symptoms (such as hallucinations, disorganized speech, or negative symptoms). The delusions are often non-bizarre (i.e., plausible but untrue), and overall functioning is relatively preserved. This patient has bizarre delusions (government surveillance), auditory hallucinations, and functional decline, which are not consistent with delusional disorder.
Answer choice C: Schizoaffective disorder, is incorrect. Schizoaffective disorder is characterized by an uninterrupted period of illness during which there is a major mood episode (depressive or manic) concurrent with active-phase schizophrenia symptoms. Delusions or hallucinations must also be present for ≥2 weeks in the absence of mood symptoms. This patient shows no evidence of mood symptoms such as depression or mania. Therefore, schizoaffective disorder is ruled out.
Answer choice E: Schizophreniform disorder, is incorrect. Schizophreniform disorder meets the same symptom criteria as schizophrenia (i.e., ≥2 of the 5 characteristic symptoms, including at least one of delusions, hallucinations, or disorganized speech), but differs in duration, lasting more than 1 month but less than 6 months. This patient has had symptoms for 8 months, which is too long for this diagnosis.
Key Learning Point
Schizophrenia is diagnosed when a patient exhibits at least two characteristic psychotic symptoms, with at least one being a core symptom (delusions, hallucinations, or disorganized speech), for a minimum duration of 6 months, and with clear functional impairment. It is distinguished from related disorders primarily by duration and the presence or absence of mood symptoms or other psychotic features.
