The effect of bright light therapy in patients with mood disorders: Brain imaging study

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K16651
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52030:Psychiatry-related
• Research Institution: Oita University
• Principal Investigator: Hirakawa Hirofumi 大分大学, 医学部, 講師 (60793768)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 気分障害 / 高照度光療法 / 脳画像研究 / 神経新生 / 海馬歯状回 / MRI

Outline of Final Research Achievements

A 4-week RCT was conducted in which patients with mood disorders were randomly assigned to either a BL group (10,000 lx) or dim light exposure group (DL group; 50 lx). All patients underwent clinical assessment and magnetic resonance imaging at baseline and after the intervention. Our final sample included 24 patients (BL group, n = 12; DL group, n = 12). A significant effect of time and group was detected in the volumes of the left DG-head (F (1, 62.9) = 11.6, partial η2 = 0.35, p = 0.003). Additionally, the BL group demonstrated a significant increase in the volume of the left DG-head (95% CI: -5.4 to -1.6, d = 1.2, p = 0.002). In conclusion, our study results suggest that compared to DL, BL leads to a significantly greater increase in the left DG volume in patients with mood disorders. This increase in the left DG volume may be associated with mood improvement in the patients.

Free Research Field

気分障害

Academic Significance and Societal Importance of the Research Achievements

気分障害患者に対する高照度光療法が左海馬歯状回頭部の体積を増加させ、同部位での神経新生が生じた可能性が示唆されたとの結果を得ることが出来た。気分障害患者における精神症状と脳画像変化の関連をみていくなかで、光療法の新たな作用機序を提唱することが出来た点で、学術的・社会的意義がある。