Mental Illness

It gets better

Many studies (e.g., Okui 2020, Le Bon 2014, Blanchflower and Oswald 2009) have claimed that mental health exhibits a U shape where mental health decrease with a nadir at middle age and then increases as people grow into their elderly years. However, a recent study by Dijk and Mierau (2022) finds that mental health may be largely improving throughout a person’s life up until perhaps the end of life.

This finding is based on data from the US Panel Study of Income Dynamics (PSID), German Socio-Economic Panel (SOEP) and the Dutch Longitudinal Internet Studies for the Social sciences (LISS) panel data sets. The PSID data uses the Kessler psychological distress scale (K-6) to measure mental health; the German data uses Mental Component Summary scale (MCS) computed from answers to the SF-12v2 questionnaire to measure mental health, and the Dutch data uses the 5-question version of the Mental Health Inventory (MHI-5).

The graphs below show trends in mental health scores by age for multiple different cohorts of individuals. In the graphs, higher scores imply better mental health.

The authors summarize their findings as follows:

While a significant body of literature suggests that the age-profile of mental health might be U-shaped, we find no evidence for a U-shape. On the contrary, our results indicate that the relationship between mental health and age could potentially follow an inverse U-shape, where individuals experience a mental health high at some point during their lives. This finding is highly societally relevant as it suggests that the young and older adults might be particularly at risk for mental health problems. 

In the statistical analysis, the study does find that the second derivative of mental health with respect to age is negative (i.e., an inverted U-shape). From the raw data, however, it appears that generally mental health improves over time and only really declines towards the very end of life. In short, for our young adults experiencing mental health issues, the data show that for many of them, mental health issues may improve over time.