Bright light treatment, sleep, and major depressive disorder in Parkinson’s disease


  • For those with Parkinson’s disease (PD), bright light therapy (BLT) improved subjective sleep quality but was not more effective than a control at alleviating depressive symptoms.

Why this matters

  • This first-ever randomized, controlled trial provides Class I evidence that BLT is not an appropriate treatment for moderately-severe major depressive disorder (MDD) in PD.