Associations between mental health and lifestyle changes during the COVID-19 pandemic in a general Japanese population: NIPPON DATA2010.

Background: Deterioration in lifestyle associated with poor mental health could be an important concern during the coronavirus disease 2019 (COVID-19) pandemic. However, few studies have investigated the association between mental health status and lifestyle changes during the pandemic in nationwide Japanese general population.

Methods: This cross-sectional study was conducted using the data among 1,546 participants of the follow-up study of NIPPON DATA2010 in 2021. Recent mental status, as assessed using the Kessler 6 (K6) scale, and lifestyle changes compared to before the pandemic were determined using self-reported questionnaires. Some lifestyle changes such as decreased physical activity were defined as undesirable, whereas others such as decreased alcohol drinking were defined as desirable. The participants were divided into three groups based on the K6 scores: the K6<5, 5≤K6<9, and K6≥9 groups. The odds ratios (ORs) and 95% confidence intervals (CIs) of the K6 groups for each lifestyle change compared with that in the K6<5 group were estimated after adjusting for possible confounders.

Results: The ORs of the K6≥9 group for all undesirable lifestyle changes were significantly high, especially increased alcohol drinking (OR 4.64; 95% CI, 2.71-7.93), and decreased physical activity (OR 4.63; 95% CI, 3.29-6.52). Among the desirable changes, the OR of the 5≤K6<9 group was significantly high for increased eating home cooking.

Conclusions: Poor mental health showed a significant association with undesirable lifestyle changes, especially increased alcohol drinking and decreased physical activity, in a nationwide general Japanese population during the COVID-19 pandemic.