Psych · Psychopharmacology — phototherapy and chronotherapy
Phototherapy and chronotherapy
Also known as Bright light therapy · Light therapy · BLT · Wake therapy · Sleep deprivation antidepressant · Triple chronotherapy · Dark therapy
Exam-exhaustive fellowship reference on phototherapy (bright light therapy) and chronotherapy — 10,000 lux protocols, SAD and nonseasonal depression evidence (Golden, Can-SAD, Lam 2016, Pjrek), circadian phase-response logic, bipolar midday light (Sit), wake therapy and triple chronotherapy, safety and regional deltas. FRANZCP-primary, globally tagged.
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Red flags
- Emergent hypomania or mania after bright light or wake therapy — stop or reduce light, reassess bipolar spectrum, stabilise mood
- Severe depression with active suicidality, psychosis, catatonia, or poor intake — do not rely on a light box alone; escalate intensity of care
- Ocular disease, recent eye surgery, or photosensitising medication without review before high-intensity BLT
- Late-evening therapeutic bright light for depression — risks phase delay and insomnia
- Aggressive early-morning high-dose light in bipolar depression without mood-stabiliser cover and switch monitoring
- Unsupervised overnight wake therapy in medically unstable or high-fall-risk patients
Meet the patient
A 34-year-old nurse presents every November like clockwork. She sleeps eleven hours a night, eats toast until the loaf is gone, and has stopped seeing her friends by midwinter. She is not suicidal, but she is "gone" — heavy, slow, and convinced she is lazy. She read about a light box online and asks if it is "real medicine."[1][6]
Every examiner's question: "Is light therapy evidence-based for this patient, and how do you prescribe it?" The answer is yes, with named parameters — and the wrong clock time can make her worse.[5][8][18]
References18ShowHide
- [1]Rosenthal NE, Sack DA, Gillin JC, et al. Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy. Arch Gen Psychiatry, 1984.PMID 6581756
- [2]Eastman CI, Young MA, Fogg LF, et al. Bright light treatment of winter depression: a placebo-controlled trial. Arch Gen Psychiatry, 1998.PMID 9783558
- [3]Terman M, Terman JS, Ross DC. A controlled trial of timed bright light and negative air ionization for treatment of winter depression. Arch Gen Psychiatry, 1998.PMID 9783557
- [4]Lewy AJ, Bauer VK, Cutler NL, et al. Morning vs evening light treatment of patients with winter depression. Arch Gen Psychiatry, 1998.PMID 9783559
- [5]Golden RN, Gaynes BN, Ekstrom RD, et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psychiatry, 2005.PMID 15800134
- [6]Terman M, Terman JS. Light therapy for seasonal and nonseasonal depression: efficacy, protocol, safety, and side effects. CNS Spectr, 2005.PMID 16041296
- [7]Wirz-Justice A, Benedetti F, Berger M, et al. Chronotherapeutics (light and wake therapy) in affective disorders. Psychol Med, 2005.PMID 16045060
- [8]Lam RW, Levitt AJ, Levitan RD, et al. The Can-SAD study: a randomized controlled trial of the effectiveness of light therapy and fluoxetine in patients with winter seasonal affective disorder. Am J Psychiatry, 2006.PMID 16648320
- [9]Lewy AJ, Lefler BJ, Emens JS, et al. The circadian basis of winter depression. Proc Natl Acad Sci U S A, 2006.PMID 16648247
- [10]Terman JS, Terman M, Lo ES, et al. Circadian time of morning light administration and therapeutic response in winter depression. Arch Gen Psychiatry, 2001.PMID 11146760
- [11]Sit D, Wisner KL, Hanusa BH, et al. Light therapy for bipolar disorder: a case series in women. Bipolar Disord, 2007.PMID 18076544
- [12]Colombo C, Lucca A, Benedetti F, et al. Total sleep deprivation combined with lithium and light therapy in the treatment of bipolar depression: replication of main effects and interaction. Psychiatry Res, 2000.PMID 10904122
- [13]Benedetti F, Riccaboni R, Locatelli C, et al. Rapid treatment response of suicidal symptoms to lithium, sleep deprivation and light therapy (chronotherapeutics) in drug-resistant bipolar depression. J Clin Psychiatry, 2014.PMID 24345382
- [14]Rohan KJ, Mahon JN, Evans M, et al. Randomized Trial of Cognitive-Behavioral Therapy Versus Light Therapy for Seasonal Affective Disorder: Acute Outcomes. Am J Psychiatry, 2015.PMID 25859764
- [15]Lam RW, Levitt AJ, Levitan RD, et al. Efficacy of Bright Light Treatment, Fluoxetine, and the Combination in Patients With Nonseasonal Major Depressive Disorder: A Randomized Clinical Trial. JAMA Psychiatry, 2016.PMID 26580307
- [16]Al-Karawi D, Jubair L. Bright light therapy for nonseasonal depression: Meta-analysis of clinical trials. J Affect Disord, 2016.PMID 27011361
- [17]Sit DK, McGowan J, Wiltrout C, et al. Adjunctive Bright Light Therapy for Bipolar Depression: A Randomized Double-Blind Placebo-Controlled Trial. Am J Psychiatry, 2018.PMID 28969438
- [18]Pjrek E, Friedrich ME, Cambioli L, et al. The Efficacy of Light Therapy in the Treatment of Seasonal Affective Disorder: A Meta-Analysis of Randomized Controlled Trials. Psychother Psychosom, 2020.PMID 31574513