A Low-Risk Treatment for Associated Symptoms
REVIEW OF: Rolland B et al, J Neural Transm 2026
STUDY TYPE: Review
Background
Circadian disruption, poor sleep, and mood instability are central features of addiction — and light therapy directly targets all three. Yet it’s almost never used in addiction treatment. This review from France makes a case for more research in this area where controlled trials are lacking.
Outside of addiction, the evidence for light therapy is solid. It first-line for seasonal affective disorder and a recommended adjunct for non-seasonal and bipolar depression, where it works as fast as antidepressants and enhances their effect. It treated depression in trials of adolescents, older adults, anorexia, and pregnancy/peripartum.
Light therapy is also recognized in the 2023 European Insomnia Guidelines and is the cornerstone treatment for delayed sleep-wake phase disorder — a pattern extremely common in substance users who have fragmented their social rhythms. Smaller randomized trials suggest benefits in:
- PTSD (regardless of season)
- Schizophrenia (negative and depressive symptoms)
- Bulimia (eating and mood symptoms in winter)
- Low sexual desire (in men and women in winter)
- Dementia (agitation, mood, sleep, and symptoms of confusion and cognition, regardless of season)
- Traumatic brain injury (mood, energy, and sleep, regardless of season)
The review states that there are no controlled trials of light therapy in addictions, but they missed a very small controlled trial of dawn simulation for winter depression in people who had recovered from alcohol use disorder, where dawn simulation was twice as effective as a placebo light.
You have to take care to select an effective box, but the standard protocol is simple: 10,000 lux for 30 minutes each morning, lightbox placed 40–80 cm away, no direct staring required.
Proposed Benefits in Addiction
- Light therapy could treat mood and anxiety symptoms that drive continued use in both substance and behavioral addictions.
- Sleep restoration reduces relapse vulnerability across virtually every substance class — tobacco, alcohol, cannabis, cocaine, opioids — and light therapy is one of the few safe tools that can improve sleep without adding another drug.
- Night owls are at greater risk for addiction and often use substances in the evening hours. Morning light and evening darkness help correct this circadian rhythm.
- More speculatively, light therapy may directly modulate reward circuitry through circadian-dopaminergic interactions, potentially reducing craving and loss of control.
Practice Implications
- Light therapy is a low-risk intervention
- While we can’t say that it treats addictions, it may help associated symptoms of sleep, depression, and anxiety that go along with addictions
- Consider starting as dawn simulation, which is easy to implement (works while asleep) and has some support in this population
- “Night owl” types are at risk for addictions, and evening dark therapy and morning light therapy help night owls function better.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
What’s Your Take? Share in Comments
- Have you tried light or dark therapy in people with addictions? What have you seen?
