Antidepressant effect of bright light therapy on patients with Alzheimer's disease and their caregivers

Xi Mei; Chenjun Zou; Zizhen Si; Ting Xu; Jun Hu; Xiangping Wu; Chengying Zheng

doi:10.3389/fphar.2023.1235406

Antidepressant effect of bright light therapy on patients with Alzheimer's disease and their caregivers

Front Pharmacol. 2023 Nov 15:14:1235406. doi: 10.3389/fphar.2023.1235406. eCollection 2023.

Authors

Xi Mei¹, Chenjun Zou², Zizhen Si³, Ting Xu², Jun Hu², Xiangping Wu¹, Chengying Zheng²

Affiliations

¹ Key Lab, Ningbo Kangning Hospital, Ningbo, Zhejiang, China.
² Department of Geriatric, Ningbo Kangning Hospital, Ningbo, Zhejiang, China.
³ Medical College, Ningbo University, Ningbo, Zhejiang, China.

Abstract

Background: As a non-pharmacologic treatment, bright light therapy (BLT) is often used to improve affective disorders and memory function. In this study, we aimed to determine the effect of BLT on depression and electrophysiological features of the brain in patients with Alzheimer's disease (AD) and their caregivers using a light-emitting diode device of 14000 lux. Methods: A 4-week case-control trial was conducted. Neuropsychiatric and electroencephalogram (EEG) examination were evaluated at baseline and after 4 weeks. EEG power in delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), and beta (12-30 Hz) bands was calculated for our main analysis. Demographic and clinical variables were analyzed using Student's t test and the chi-square test. Pearson's correlation was used to determine the correlation between electrophysiological features, blood biochemical indicators, and cognitive assessment scale scores. Results: In this study, 22 in-patients with AD and 23 caregivers were recruited. After BLT, the Hamilton depression scale score decreased in the fourth week. Compared with the age-matched controls of their caregivers, a higher spectral power at the lower delta and theta frequencies was observed in the AD group. After BLT, the EEG power of the delta and theta frequencies in the AD group decreased. No change was observed in blood amyloid concentrations before and after BLT. Conclusion: In conclusion, a 4-week course of BLT significantly suppressed depression in patients with AD and their caregivers. Moreover, changes in EEG power were also significant in both groups.

Keywords: Alzheimer’s disease; EEG; biomarkers; bright light therapy; depression.

Grants and funding

The study was funded by Ningbo City Key R&D plan “Jie Bang Gua Shuai” (2023Z170), Ningbo City Public welfare Science and technology Plan project (2022S025), Zhejiang Medical and Health Science and Technology Project (2022KY1174), Ningbo Medical and Health Leading Academic Discipline Project (2022-F28), and the Major Fund Project of Ningbo Science and Technology Bureau (2019B10034). The sponsor had no role in the design or conduct of this research.