Typical major depressive disorder with insomnia, appetite loss, and psychomotor retardation as the expected presenting features.

Typical MDD features insomnia (not hypersomnia), appetite decrease (not increase), and psychomotor agitation or retardation — the opposite pattern. While MDD is a broad diagnosis, this specific symptom cluster warrants the atypical specifier.

Hypothyroidism presenting with fatigue, weight gain, and cognitive slowing that would require a TSH to confirm the diagnosis.

Hypothyroidism should be screened for (TSH), but the rejection sensitivity, mood reactivity, and carbohydrate craving pattern is more specific to atypical depression than to thyroid disease.

Chronic fatigue syndrome, as the excessive sleep and sensation of heaviness in the extremities are the most prominent findings.

Chronic fatigue syndrome does not typically present with mood reactivity, rejection sensitivity, and carbohydrate craving. The full symptom pattern is more consistent with atypical depression.

MDD with atypical features, given the combination of hypersomnia, increased appetite, leaden paralysis, and rejection sensitivity.

The DSM-5 "with atypical features" specifier requires mood reactivity plus two or more of: hypersomnia, increased appetite or weight gain, leaden paralysis, and long-standing interpersonal rejection sensitivity. This pattern is important to recognize because it influences medication selection and because atypical features are disproportionately associated with bipolar II depression — requiring bipolar screening before initiating antidepressant monotherapy.