Examkin

Question

Difficulty: Very hardSchizophrenia and Psychotic Disorders

A 32-year-old man is brought to the outpatient psychiatry clinic by his parents due to chronic behavioral changes. They report that their son has been behaving abnormally for the past 3 years. It began when he started claiming that national television news anchors were communicating with him through coded hand gestures. He also frequently converses with voices that no one else can hear. According to the parents, these beliefs and hallucinations have been continuously present since their onset. During this 3-year period, the patient experienced three distinct episodes of profound sadness, anhedonia, hypersomnia, and feelings of worthlessness. Each of these episodes lasted approximately 2 months and resolved spontaneously, with him returning to a normal mood. He is currently displaying a flat affect and reports that the news anchors are still sending him messages, but he denies any current sadness or changes in sleep, appetite, or energy. His medical history is unremarkable, and a urine toxicology screen is negative. Which of the following is the most likely diagnosis?

  1. SchizophreniaAnswer
  2. B
    Schizoaffective disorder
  3. C
    Major depressive disorder with psychotic features
  4. D
    Schizophreniform disorder
  5. E
    Brief psychotic disorder

Answer

Schizophrenia
The diagnosis is schizophrenia because the patient has had active psychotic symptoms (delusions, hallucinations) for greater than 6 months. While he has experienced major depressive episodes, they have not been present for the majority of the total duration of the active and residual portions of the illness (occurring for only 6 months out of a 36-month period). Furthermore, he demonstrates prominent psychotic symptoms in the absence of a mood episode, distinguishing it from a mood disorder with psychotic features.

Step-by-Step Solution

1
Determine the total duration of the primary psychotic symptoms.
The patient has experienced continuous delusions and hallucinations for 36 months (3 years).
Establishing the total timeline of psychosis is the first step in differentiating schizophrenia-spectrum disorders.
2
Assess the longitudinal relationship between mood episodes and psychotic symptoms.
Psychotic symptoms are present continuously, including times when the patient is completely euthymic.
This confirms that the psychosis is independent, ruling out a mood disorder with psychotic features (where psychosis occurs only during the mood episode).
3
Calculate the proportion of the illness course affected by mood episodes.
Mood episodes account for 6 months (three 2-month episodes) out of a 36-month total illness duration, which is approximately 17%.
To differentiate schizophrenia from schizoaffective disorder, the mood episodes must be present for the majority (greater than 50%) of the total illness duration. Since 17% is not the majority, the correct diagnosis is schizophrenia.

Key Concept

To diagnose schizoaffective disorder, symptoms of a major mood episode must be present for the majority of the total duration of the active and residual portions of the illness; otherwise, a diagnosis of schizophrenia with concurrent mood episodes is more appropriate.
Rate this question

Topics

Schizophrenia and Psychotic Disorders

More questions from this topic