[Light therapy for depression].

Artificial light has been used as a treatment for depression since the 1980s. The indications have since broadened from seasonal depression to non-seasonal depression including bipolar, geriatric, and chronic depression. Light acts through retinohypothalamic connections from specialised retinal neurons to central nuclei involved in circadian and emotional regulation. This review illuminates the current strategies directed towards utilising natural daylight or electric lighting mimicking the dynamic spectrum and intensity of daylight to improve treatment in modern hospital settings.

Light therapy for seasonal affective disorder in visual impairment and blindness - a pilot study.

OBJECTIVE: Seasonal and non-seasonal depression are prevalent conditions in visual impairment (VI). We assessed the effects and side effects of light therapy in persons with severe VI/blindness who experienced recurrent depressive symptoms in winter corresponding to seasonal affective disorder (SAD) or subsyndromal SAD (sSAD). RESULTS: We included 18 persons (11 with severe VI, 3 with light perception and 4 with no light perception) who met screening criteria for sSAD/SAD in a single-arm, assessor-blinded trial of 6 weeks light therapy. In the 12 persons who completed the 6 weeks of treatment, the post-treatment depression score was reduced (p < 0.001), and subjective wellbeing (p = 0.01) and sleep quality were improved (p = 0.03). In 6/12 participants (50%), the post-treatment depression score was below the cut-off set for remission. In four participants with VI, side effects (glare or transiently altered visual function) led to dropout or exclusion. CONCLUSION: Light therapy was associated with a reduction in depressive symptoms in persons with severe VI/blindness. Eye safety remains a concern in persons with residual sight.

Dynamic LED-light versus static LED-light for depressed inpatients: study protocol for a randomised clinical study.

INTRODUCTION: Retrospective studies conducted in psychiatric inpatient wards have shown a relation between the intensity of daylight in patient rooms and the length of stay, pointing to an antidepressant effect of ambient lighting conditions. Light therapy has shown a promising antidepressant effect when administered from a light box. The emergence of light-emitting diode (LED) technology has made it possible to build luminaires into rooms and to dynamically mimic the spectral and temporal distribution of daylight. The objective of this study is to investigate the antidepressant efficacy of a newly developed dynamic LED-lighting system installed in an inpatient ward. METHODS AND ANALYSIS: In all, 150 inpatients with a major depressive episode, as part of either a major depressive disorder or as part of a bipolar disorder, will be included. The design is a two-arm 1:1 randomised study with a dynamic LED-lighting arm and a static LED-lighting arm, both as add-on to usual treatment in an inpatient psychiatric ward. The primary outcome is the baseline adjusted score on the 6-item Hamilton Depression Rating Scale at week 3. The secondary outcomes are the mean score on the Suicidal Ideation Attributes Scale at week 3, the mean score on the 17-item Hamilton Depression Rating Scale at week 3 and the mean score on the World Health Organisation Quality of Life-BREF (WHOQOL-BREF) at week 3. The spectral distribution of daylight and LED-light, with a specific focus on light mediated through the intrinsically photosensitive retinal ganglion cells, will be measured. Use of light luminaires will be logged. Assessors of Hamilton Depression Rating Scale scores and data analysts will be blinded for treatment allocation. The study was initiated in May 2019 and will end in December 2021. ETHICS AND DISSEMINATION: No ethical issues are expected. Results will be published in peer-reviewed journals, disseminated electronically and in print and presented at symposia. TRIAL REGISTRATION NUMBER: NCT03821506; Pre-results.

[Psychiatry and circadian rhythms].

Circadian and seasonal rhythm disturbances are prominent in patients with psychiatric disorders. Properly timed and dosed light of specific spectral composition stabilises mood and sleep through serotonergic mechanisms and through input to the master circadian clock in the hypothalamus. Correctly administered, light can be used as an effective treatment for seasonal and non-seasonal depression and for stabilising the sleep-wake cycle. Blocking blue light in the evening may provide a non-pharmacological anti-manic tool. Current developments use dynamic lighting built into somatic and psychiatric hospitals to maximise the beneficial effects of light.

[More than every tenth person have symptoms of seasonal affective disorder]. / Mere end hver tiende har symptomer på vinterdepression.

Seasonal affective disorder is a syndrome of classical depressive symptoms such as reduced energy, initiative and mood combined with atypical symptoms of increased appetite, weight and sleep duration. The symptoms recur each winter and disappear again in spring or early summer. The prevalence ranges from 1% to 10% in Scandinavian populations. Reduced light exposure, melatonergic and serotonergic disturbances are suggested pathogenetic factors. Light therapy offers convincing effect with minimal adverse effects and remains first-line treatment along with selective serotonin reuptake inhibitors.