Study: Light therapy is effective in treating seasonal affective disorder

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An analysis published in Psychotherapy and Psychosomatics documents the value of light therapy in treating seasonal affective disorder.Seasonal affective disorder (SAD) is a subtype of recurrent major depressive or bipolar disorder defined by a regular temporal relationship (over at least two years) between the onset and remission of affective episodes and a particular time of the year.The most frequent pattern is fall-winter depression with onset of depression during fall or winter with spontaneous remission or, optionally, hypomania/mania during the subsequent spring/summer period. Bright light therapy has been used as a treatment for seasonal affective disorder for over 30 years.

This meta-, including randomized, single- or double-blind clinical trials investigating Bright light therapy(≥1,000 lx, light box or light visor) against dim light (≤400 lx) or sham/low-density negative ion generators as placeb, assesses the efficacy of bright light therapy in the treatment of seasonal affective disorder in adults.Treatment effectiveness was evaluated as the post-treatment depression score measured by validated scales, and as the rate of response to treatment.

A total of 19 studies met inclusion criteria. Results showed that bright light therapy was superior over placebo with a standardized mean difference of –0.37 (95% CI: –0.63 to –0.12) for depression ratings (18 studies, 610 patients) and a risk ratio of 1.42 (95% CI: 1.08–1.85) for response to active treatment (16 studies, 559 patients).

Authors concluded that bright light therapy can be regarded as an for , but the available evidence stems from methodologically heterogeneous studies with small-to-medium sample sizes, necessitating larger high-quality clinical trials.

More information: Edda Pjrek et al. The Efficacy of Light Therapy in the Treatment of Seasonal Affective Disorder: A Meta-Analysis of Randomized Controlled Trials, Psychotherapy and Psychosomatics (2019). DOI: 10.1159/000502891

Journal information: Psychotherapy and Psychosomatics

Provided by Journal of Psychotherapy and Psychosomatics
Citation: Study: Light therapy is effective in treating seasonal affective disorder (2020, April 10) retrieved 29 November 2023 from
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