This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mood Disorders, Subject name: Psychiatry
[{'content': 'A 40 year old woman is being evaluated. She is noted to have a decreased latency of REM. Which disorder is this woman most likely to be suffering from? \nSelect and explain. \nA. Schizophrenia, B. Major depression, C. PTSD, D. Obsessive-compulsive disorder', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Major depressionA decreased latency of REM sleep is seen in major depression. Depression is the psychiatric disorder that has been most associated with disruptions in biological rhythms. Besides the decreased latency of REM sleep, one can find early morning awakening and other neuroendocrine perturbations.', 'role': 'assistant'}]