Understanding the impact of psychological problems on life expectancy in Japan

The Japanese population is known for having the longest life expectancy (LE) at birth. Extensive studies have been conducted on the physical health of the Japanese population, mainly on mortality rates. However, mental health research is limited due to the social stigma against mental illness. This is alarming because mental health issues such as anxiety, substance use disorders, and suicide rates have largely increased over the years.

Furthermore, previous studies have examined the physical and mental health of the Japanese population separately, making it more difficult to understand the relationship between them.

Against this background, Associate Professor Yuka Minagawa from Sophia University’s Faculty of Liberal Arts assessed trends in the relationship between physical and mental health in terms of health expectancy: the average number of years a person is likely to live in a given area. health status among the Japanese population between 2010 and 2022. Notably, this study is the first to use data on psychological problems to calculate health expectancy in Japan. The findings have been published in the Asian social work and policy overview on September 3, 2024.

Dr. Minagawa emphasizes the rationale behind the study, saying: “Although the concept of health expectancy is receiving increasing attention as a comprehensive measurement of population health status, most studies in Japan have focused solely on physical health indicators and overlooked the role of mental health . This study addresses this gap by estimating lifespan. free from psychological problems.”

To this end, mortality data were taken from life tables published by the Ministry of Health, Labor and Welfare (MHLW), and data on psychological problems were taken from the Comprehensive Survey of Living Condition (CSLC), also conducted by the MHLW. The prevalence of psychological problems was measured using the Japanese version of the Kessler Psychological Distress Scale 6. Sullivan’s method was then used to combine these data and calculate health expectancy among men and women aged 20 years or older.

The findings showed that both men and women experienced substantial improvements in problem-free LE, with younger individuals benefiting most. However, older adults, Men in particular were more likely to have problems for a variety of reasons, including widowhood. Dr. Minagawa says: “Widowhood negatively impacts men’s mental health, leading to psychological distress and depression, as they have to adapt to lifestyle changes without support from their partner.”

Initially, distress-free LE for men and women of all ages declined between 2010 and 2013, likely due to psychosocial stressors such as the 2011 Great East Japan Earthquake and Tsunami. However, it improved over the course of 2022. This increase in emergency-free LE between 2019 and 2022, despite the COVID-19 pandemic, does not mean that the mental health of the Japanese population remained unaffected.

Differences in emergency-free LE between 2010 and 2022 were also analyzed to understand the extent to which these were driven by changes in age-specific mortality rates and the prevalence of psychological problems. Among men of all ages, changes in mortality had a more positive impact on stress-free LE than changes in psychological distress. However, in women, both changes in mortality and psychological distress contributed to improvements in distress-free LE.

These findings highlight the need for targeted interventions to support mental health in Japan. Dr. Minagawa says: “The study advances our understanding of public health by highlighting the critical role of mental health in the overall well-being of the population. As the prevalence of mental health problems increases, policymakers must focus on the complex relationship between physical and mental health in today’s society. Japan.”