Socioeconomic status, psychotherapy duration, and return to work from disability due to common mental disorders

How does working time impact perceived mental disorders? New insights into the U-shaped relationship

Based on a large-scale nationally representative survey in China, this paper uses the exogenous impact of automation on working hours as the instrumental variable to examine working time's impact on perceived mental disorders, on the basis of dealing with endogeneity. Different from existing literature, it is found that the impact of working time on perceived mental disorders is U-shaped, rather than linear. Mental disorders firstly decrease with working hours. After working more than 48.688 h per week, further increases in working time carry notable mental health costs, leading to a positive relationship between working hours and depression. The turning point of this U-shaped relationship is almost in line with the International Labor Organization's 48 working hours/week standard, justifying it from a mental health perspective. In addition, we further exclude the possibility of more complex nonlinear relationships between working time and perceived mental disorders. Furthermore, heterogeneities are found in the effects of working hours on mental disorders across different subgroups. Males are more depressed when working overtime. Older workers have a lower tolerance for overwork stress. The turning point is smaller for the highly educated group and they are more sensitive to working longer. Those with higher socioeconomic status are less depressed after exceeding the optimal hours of work. The increase in depression among rural workers faced with overwork is not prominent. Perceived mental disorders are lower among immigrants and those with higher health status. In addition, labor protection and social security help to weaken mental disorders caused by overtime work. In conclusion, this paper demonstrates that working time has a U-shaped impact on perceived mental disorders and highlights the vulnerability of certain groups, providing a reference for setting optimal working hours from a mental health perspective.

Psychotherapy duration and work disability: A prospective Finnish register study

INTRODUCTION

The influence of psychotherapy duration on common mental disorder (CMD) outcomes remains a topic of ongoing debate. Whereas most research has focused on CMD symptom change, the evidence on the psychotherapy duration of subsequent CMD-related work disability and the change in psychotropic drug purchases is scarce.

METHODS

We used a register-based cohort representing 33% of the Finnish population. The participants included working-age individuals (N = 12,047, 76% women, mean age = 36) who initiated long-term psychotherapy, between 2014 and 2017. They were followed from 2011 to 2021 and psychotherapy duration ranged from less than a year to over 3 years. We used an interrupted time series design to analyze the psychotherapy duration-dependent changes in CMD-related work disability (primary outcome, operationalized as depression or anxiety-related sickness absence, SA, days) and the annual number of psychotropic drug purchases or distinct drugs purchased (secondary outcomes).

RESULTS

There were no differences in the levels of work disability or drug purchases before the psychotherapy. We observed a decreasing level and trend in all outcomes across all psychotherapy duration groups. The largest decline in level was observed in the <1-year duration group (88% decline for SA and 43%-44% for drug purchases) while the smallest decline was in the 3+ years duration group (73% for SA and 27% for drug purchases).

CONCLUSION

Work disability outcomes and duration varied among individuals, even with similar initial mental health-related work disability or use of auxiliary psychotropic treatments. Compared to longer psychotherapy, shorter psychotherapy was associated with sharper improvements.