Sleep patterns and melatonin rhythms in teens and young adults with depression or bipolar disorder

Patients with bipolar disorders had significantly lower levels and later onset of melatonin secretion than those with unipolar depression.

• Circadian measures may serve as early indicators for different mood disorder subtypes.
• Bipolar disorder patients exhibited later melatonin secretion compared to unipolar depression patients.
• Several patients showed abnormal timing relationships between sleep, melatonin, and body temperature.

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