Final answer:
Anhedonia is not part of the DSM-IV criteria for diagnosing atypical depression which includes increased appetite/weight gain, hypersomnia, and leaden paralysis. Anhedonia is instead a core symptom of major depression.
Step-by-step explanation:
In the context of the DSM-IV criteria for diagnosing atypical depression, the correct option that is NOT part of the criteria is D. Anhedonia.
To diagnose atypical depression, several symptoms including increased appetite or weight gain, hypersomnia (excessive sleeping), and leaden paralysis (a heavy feeling in the arms or legs) should be present. Anhedonia, which is a lack of interest or pleasure in all or most activities, is not a defining symptom of atypical depression, but rather a core symptom of major depression.
Atypical depression has specific features that differentiate it from major depression. These features can affect treatment choices, as certain antidepressants may be more effective for atypical depression. Consequently, accurate diagnosis is crucial for effective treatment.