Income gradient in psychotherapy use and psychotropic drug purchases: A longitudinal register study in Finnish employed population

Abstract

Objective: We examined the income gradient changes in the use of long-term rehabilitative psychotherapy and psychotropic drug purchases in men and women during a 9-year follow-up.

Methods: We used register data from a random sample of the working-age population (18-64 years) with information on annual income, psychotherapy use and psychotropic drug purchases from 2011 to 2019 (N = 736 613, 49.7% women). Sex-stratified generalized estimating equations logistic regression models with predicted marginal probabilities were used to examine change in the treatment use rates over time for income quartiles.

Results: Treatment rates increased during the follow-up, with men having lower rates than women. There were no significant differences in psychotherapy use rates between the income quartiles during the follow-up in men. A small income gradient in women (the wealthiest group with the highest use rate) remained stable throughout the follow-up. As for psychotropic drug purchases, the rates increased more among the poorest income quartile compared to the wealthiest quartile in both men and women. In the last year of the follow-up, the initial income gradient (wealthiest group having the highest psychotropic drug purchase rate) had become reversed, and the poorest group had the highest psychotropic drug purchase rate.

Conclusion: In psychotherapy use, no income gradient was found in men, while a stable income gradient was found in women. Psychotropic drug purchases have previously been more common in the wealthiest groups, but more recently among the poorest. The findings indicate that gender and income have distinct relationships with the treatment modality over time.

Keywords: Gender; Income; Mental health; Psychotherapy; Psychotropic drug; Socioeconomic.