Morning bright light improved anhedonia scores in a depression trial
Patients receiving morning bright light improved on a physical anhedonia scale compared with morning placebo; the abstract does not establish that morning treatment outperforms evening treatment.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Morning bright light improved scores measuring reduced ability to experience physical pleasure, compared with morning placebo. Changes in those scores were associated with a later melatonin peak. This association does not show that the hormone timing caused the improvement, and the abstract supplies no direct evidence that morning light was better than evening light.
The abstract gives no size or confidence interval for the anhedonia benefit and no direct morning-versus-evening estimate. This abstract-based account cannot assess whether the change was meaningful to patients or persisted.
What researchers found
Revised Physical Anhedonia Scale score
Morning bright light versus morning placebo after 2 weeks; the abstract does not report the size of the score difference.
A symptom-specific primary outcome
The main question concerned anhedonia rather than recovery from depression overall. The trial also measured depression ratings and salivary hormones, allowing researchers to explore whether changes in pleasure-related symptoms tracked changes in hormone timing.
Timing remains an open question
Depressive symptoms improved after both morning and evening bright light. However, the abstract does not specify the placebo comparison for that statement or provide an evening anhedonia estimate, leaving the relative merits of the schedules uncertain.
The original publication
The impact of timing on bright light therapy: Alleviating anhedonia and circadian rhythm disturbances in depression patients: a randomized controlled trial.
Li X, Qin X, Fang J et al.
J Affect Disord · 2026
- PubMed ID
- 41785919
- Record checked
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