Several studies (eg, Okui 2020, Le Bon 2014, Blanchflower, and Oswald 2009) have claimed that mental health exhibits a U-shape in which mental health decreases with nadir in middle age and then increases as people grow into old age. However, a recent study by Dijk and Mierau (2022) found that mental health may improve considerably throughout a person’s life until possibly the end of life.
This finding is based on data from the US Panel Study of Income Dynamics (PSID), German Socioeconomic Commission (SOEP), and Dutch Longitudinal Internet Studies of Social Sciences (LISS) datasets. PSID data uses the Kessler Psychological Stress Scale (K-6) to measure mental health; German data use the Mental Components Summary Scale (MCS) computed from responses to the SF-12v2 Questionnaire Measurement of Mental Health, and Dutch data use the 5-question version of the Mental Health Inventory (MHI-5).
The graphs below show trends in mental health scores by age for different groups of individuals. In the graphs, higher scores indicate better mental health.
The authors summarize their findings as follows:
While a large body of literature suggests that the age profile of mental health may be U-shaped, we find no evidence for a U-shape. On the contrary, our results suggest that the relationship between mental health and age can follow an inverted U-shape, Where individuals experience an uptick in mental health at some point during their lives. This finding is highly relevant to society because it suggests that young people and the elderly may be at particular risk of developing mental health problems.
In the statistical analysis, the study found that the second derivative of mental health with respect to age is negative (i.e. an inverted U-shape). However, from the preliminary data, it appears that mental health generally improves over time and only truly declines towards the end of life. In short, for our young people with mental health issues, the data shows that for many of them, mental health issues may improve over time.