The Social Gradient in Mental Health. A Long-Term Longitudinal Study Integrating Survey Data, Register Data, and Molecular Genetic Data

People with low income and low educational attainment have poorer health and die earlier than people with more socio-economic resources. Mental health is one of several areas in which social inequality in health is observed. In this project, we examine social inequality in a variety of mental health problems such as depression, anxiety, eating problems, conduct problems, and drug use. We want to know how social inequality in mental health develops from adolescence and into adulthood. We also examine the following questions: Which mechanisms can explain social inequality in mental health? Are some groups of youth and adults particularly vulnerable to mental health problems when living in poverty? Has social inequality in mental health among adolescents changed over time? And: does inequality in mental health vary in different parts of the country? Although Norway is a country with relatively small socio-economic differences in an international context, social inequality in health is as pronounced in Norway as in other countries. The project can provide important information on causes of social inequality in mental health that can be used to develop strategies for reducing this inequality. We use data from several large youth surveys including the Young in Oslo Surveys, "Ungdata", and the longitudinal Young in Norway Study, which follows youth into adulthood over a period of 28 years. The project is conducted at the Department of Psychology at the University of Oslo and is linked to the PROMENTA Research Center. Some of the first publications from the project focus on social inequality among adolescence during the COVID-19 pandemic. Results show that social inequality in life satisfaction among adolescents in Oslo was smaller during the pandemic than earlier. Social gradients during the pandemic in a variety of other domains of adolescents' life were examined as well. We also investigated sources of social inequality in substance use and behavioral problems among adolescents and adults.

The project aims to provide novel information about social gradients of a wide range of mental health problems, including depression, anxiety, eating disturbances, conduct problems, alcohol use, smoking, and illicit drug use. The project will examine (a) how social gradients in mental health develop from adolescence into middle adulthood; (b) how polygenic risk for mental health problems is related to social marginalization; (c) how socio-economic status and social marginalization interact with genetic risk in predicting mental health problems, and (d) how social gradients vary according to societal contexts. The project utilizes data from a large scale, longitudinal study (Young in Norway Longitudinal), spanning from adolescence over 28 years and which combines survey, register, and molecular genetic data (N=2,600). Moreover, two other large-scale representative samples of Norwegian adolescents are used to examine geographical variations in social gradients and how gradients change across time. Growth curve analyses will be used to model trajectories of mental health problems and to examine how social marginalization is related to such trajectories. Polygenic risk scores are constructed to examine how social marginalization interacts with genetic risk. Multilevel analyses will be conducted to examine how social gradients vary according to societal contexts. The project will be based at the newly established Research Center PROMENTA at the Department of Psychology, University of Oslo, in close collaboration with several national and international researchers. A user-perspective is established by collaborating with among others the Norwegian part of the WHO Healthy Cities Network "Sunne kommuner" and by consulting a reference group. By using a unique combination of different high quality data sources, this project will provide important novel knowledge about the nature of social disparities in mental health problems.