Light therapy, a non-intrusive approach, is now considered as a promising new treatment method for a variety of mood disorders such as depression, bipolar disorder, postpartum depression and so on. However, the neural mechanism of light therapy to regulate emotions is still unclear, and the clinical application of light therapy and its side effects are still controversial. Light therapy regulates mood may be related to the changes of neural circuit mediated by intrinsically photosensitive retinal ganglion cells(ipRGCs), clock gene expression, circadian rhythm and sleep structure. In this paper, the treatment of mood disorders by light has been discussed, and a variety of neural circuits and molecular biological mechanisms of light therapy are introduced, meanwhile, the current situation and side effects of light therapy have been analyzed, in order to provide evidence for the application and promotion of light therapy in the treatment of mood disorders.

Objective To explore the correlation between childhood trauma and plasma adiponectin levels in patients with depression.Methods A total of 121 patients with depression and 39 healthy controls(control group)were enrolled.Childhood trauma questionnaire(CTQ-SF)was used to assess the experience of childhood abuse and neglect,and the patients with depression were divided into trauma group(n=53)and non-trauma group(n=68)according to the CTQ-SF score.The 17-item Hamilton depression scale-17(HAMD17)and the Hamilton anxiety scale(HAMA)were used to evaluate the severity of depression and anxiety symptoms,respectively.Plasma adiponectin levels of subjects were measured by enzyme-linked immunosorbent assay.Results The plasma adiponectin level of trauma group[3.82(2.44,4.92)μg/mL]was significantly lower than that of non-trauma group[4.64(2.98,6.43)μg/mL,P=0.01]and the control group[6.29(4.54,7.51)μg/mL,P＜0.01].The plasma adiponectin level of non-trauma group was lower than that of the control group(P＜0.01).Correlation analysis showed that plasma adiponectin level in patients with depression was negatively correlated with childhood trauma(r=-0.34,P＜0.01).Multivariate linear regression analysis showed that plasma adiponectin level was negatively correlated with childhood trauma scores in patients with depression(β=-0.05,P＜0.01).Conclusions Patients with depression who have experienced childhood trauma have lower plasma levels of adiponectin,and childhood trauma may be associated with decreased plasma adiponectin levels in patients with depression.

Objective To explore whether indoor light-assisted therapy can rapidly improve depression and anxiety symptoms in patients with depression,as well as the safety of indoor-light-assisted therapy.Methods From September 2021 to December 2022,patients with depression were recruited from the Mental Health Center of the First Hospital of Hebei Medical University.According to the random number table method,patients were divided into test group and control group.The test group was treated with light therapy 30 minutes from 7:30 am to 8:00 am daily for 2 weeks in addition to antidepressant therapy.Antidepressant therapy was continued after completion of light therapy and patients were followed up for 2 weeks.The control group was treated with regular antidepressants throughout the four-week trial.Hamilton depression scale(HAMD17)and the Hamilton anxiety scale(HAMA)were used to assess the clinical symptoms at the baseline and the end of every week of treatment.Safety was evaluated using patient adverse events,anterior segment photography and visual testing.Results A total of 80 patients were enrolled,including 40 in the test group and 40 in the control group.The data of dropped were processed for missing values and then included in the statistical analysis.At the 1st(20.0％vs.0.0％)and 2nd(45.0％vs.17.5％)weekend of treatment,the response rate in the test group was significantly higher than that in the control group.There was an interaction between the time point and the group in HAMD17 total score(F=9.66,P<0.01).The scores of HAMD17 at the end of every week in the test group were significantly lower than that in the control group(P<0.05).There were significant differences in the reduction rate of total score in HAMD17[33.3％(25.0％,43.3％)vs.13.9％(9.9％,19.8％)]and HAMA[22.4％(16.5％,35.3％)vs.14.2％(4.4％,26.9％)]between the two groups(P<0.05).Incidences of adverse effect were not significantly different between the two groups(12.5％vs.10.0％,P=1.00).There were no severe adverse events or mania was reported in the test group and the eye examination showed no abnormality.Conclusion Compared with antidepressant therapy alone,indoor light therapy combined with antidepressant can quickly improve depression and anxiety symptoms in patients with depression,shorten the duration of depression treatment,and has good safety.