American Board of Psychiatry and Neurology (ABPN) Practice Exam 2025 - Free ABPN Practice Questions and Study Guide

Decreased REM latency is recognized as a primary symptom of depression due to its association with the alterations in sleep architecture typically observed in individuals with depression. REM latency refers to the duration of time it takes to reach the first episode of rapid eye movement (REM) sleep after falling asleep. In depressed individuals, this latency is often shortened, meaning they enter REM sleep more quickly than those who are not experiencing depression.

Research indicates that changes in sleep patterns, including shortened REM latency, often accompany depressive disorders. This sleep disturbance can be attributed to neurobiological factors associated with depression, such as alterations in serotonin and norepinephrine levels, which impact the sleep-wake cycle and the regulation of REM sleep. Monitoring REM sleep patterns can therefore provide insights into the severity and presence of depressive symptoms in patients, making it a crucial aspect of understanding the interplay between mood disorders and sleep abnormalities.

In contrast, while increased total sleep time, night terrors, and excessive daytime sleepiness can be related to mood disturbances or other sleep disorders, they do not specifically point to a primary symptom of depression like decreased REM latency does. These other symptoms may occur in different contexts or diagnoses, but they are less specific to depression itself.