How Psychiatric Disorders Emerge in a Transition Society: Vulnerability and Resilience in a Longitudinal Study


University of Tartu, Division of Neuropsychopharmacology, Department of Psychology, Tartu, Estonia

University of Tartu, Tartu, Estonia

University of Tartu, Tartu, Estonia

University of Tartu, Tartu, Estonia

University of Tartu, Tartu, Estonia

National Institute for Health Development, Tallinn, Estonia


Both genetic vulnerability and exposure to lifetime adversities have a causal role in psychiatric disorders. The progress of molecular genetics has led to numerous attempts, both hypothesis-guided and hypothesis-free, to identify genes that have variants responsible for vulnerability. This research is producing a continuously increasing list of implicated genes for each disorder, while some genes appear as responsible for general psychiatric vulnerability. What is not well understood is the mechanism by which environmental factors precipitate psychiatric disorders. Transition societies, almost by definition, provide a promising research venue for gene × environment interaction studies. The original sample (n=1238) of the population-representative Estonian Children Personality Behaviour and Health Study consists of two birth cohorts six years apart that have been followed since 1998, with assessment of lifetime occurrence of common psychiatric disorders by the structured MINI interview at age 25. Affective disorders, anxiety disorders and alcohol use disorders each had been experienced by about 20% of subjects, with some comorbidity so that about 45% of the sample had met criteria for a psychiatric disorder. Stressful life events play a role in the development of all disorders in this sample, while the associations of functional gene variants and life events with the psychopathology often are not only sex-dependent but also interact with the birth cohort. Examples of such genotype and birth cohort interactions most prominently appear for alcohol use disorders and involve genes like SLC6A4, VMAT1, NPSR1, OXTR and NRG1. These findings suggest that the multiple factors that are involved in the development of genetically complex disorders are related to gene × environment interactions that in turn are sensitive to the societal changes. Thus, such psychiatric disorders, despite of common clinical characterization, have major variations in underlying neurobiology and this provides strong theoretical support to individually variable needs in drug treatment.