Shafaqna English- A study in the Journal of Psychiatric Research found that healthy adults exposed to dim morning light developed biological changes associated with depression, including altered cortisol rhythms and disrupted sleep patterns, according to PsyPost.
Twenty healthy adults spent five mornings under either dim 55-lux light or brighter 800-lux light. The dim-light group showed higher cortisol levels later in the day, about 25 minutes less sleep, delayed deep sleep and increased feelings of sleepiness and sadness.
The brighter-light group maintained more typical cortisol and sleep patterns, although researchers observed increased late-night REM sleep.
The researchers said the findings suggest insufficient morning light may weaken circadian rhythms and increase vulnerability to mood disorders. However, the study was small and short-term, and it did not show that dim light causes clinical depression.
The authors said longer studies are needed to determine whether sustained exposure to low morning light produces lasting mental-health effects.
Source: PsyPost