The prevalence, incidence, and risk factors of mental health problems and mental health service use before and 9 months after the COVID-19 outbreak among the general Dutch population. A 3-wave prospective study
Authors: van der Velden Peter G. , Marchand Miquelle , Das Marcel , Muffels Ruud , Bosmans Mark 
Published: November 2022

Objectives
Gain insight into the effects of the COVID-19 pandemic on the prevalence, incidence, and risk factors of mental health problems among the Dutch general population and different age groups in November-December 2020, compared with the prevalence, incidence, and risk factors in the same period in 2018 and 2019. More specifically, the prevalence, incidence, and risk factors of anxiety and depression symptoms, sleep problems, fatigue, impaired functioning due to health problems, and use of medicines for sleep problems, medicines for anxiety and depression, and mental health service.

Methods
We extracted data from the Longitudinal Internet studies for the Social Sciences (LISS) panel that is based on a probability sample of the Dutch population of 16 years and older by Statistics Netherlands. We focused on three waves of the longitudinal Health module in November-December 2018 (T1), November-December 2019 (T2), and November-December 2020 (T3), and selected respondents who were 18 years and older at T1. In total, 4,064 respondents participated in all three surveys. Data were weighted using 16 demographics profiles of the Dutch adult population. The course of mental health problems was examined using generalized estimating equations (GEE) for longitudinal ordinal data and differences in incidence with logistic regression analyses. In both types of analyses, we controlled for sex, age, marital status, employment status, education level, and physical disease.

Results
Among the total study sample, no significant increase in the prevalence of anxiety and depression symptoms, sleep problems, fatigue, impaired functioning due to health problems, use of medicines for sleep problems, of medicines for anxiety and depression, and of mental health service in November-December 2020 was observed, compared with the prevalence in November-December 2018 and 2019 (T3 did not differ from T1 and T2). Among the four different age categories (18–34, 35–49, 50–64, and 65 years old and older respondents), 50–64 years respondents had a significantly lower prevalence of anxiety and depression symptoms at T3 than at T1 and T2, while the prevalence at T1 and T2 did not differ. A similar pattern among 65+ respondents was found for mental health service use. We found no indications that the incidence of examined health problems at T2 (no problems at T1, problems at T2) and T3 (no problems at T2, problems at T3) differed. Risk factors for mental health problems at T2 were mostly similar to risk factors at T3; sex and age were less/not a risk factor for sleep problems at T3 compared with at T2.

Conclusions
The prevalence, incidence, and risk factors of the examined mental health problems examined nine months after the COVID-19 outbreak appear to be very stable across the end of 2018, 2019, and 2020 among the Dutch adult population and different age categories, suggesting that the Dutch adult population in general is rather resilient given all disruptions due to this pandemic.