Cohort profile: SUPER-Finland - the Finnish study for hereditary mechanisms of psychotic disorders

Abstract

Purpose: SUPER-Finland is a large Finnish collection of psychosis cases. This cohort also represents the Finnish contribution to the Stanley Global Neuropsychiatric Genetics Initiative, which seeks to diversify genetic sample collection to include Asian, Latin American and African populations in addition to known population isolates, such as Finland.

Participants: 10 474 individuals aged 18 years or older were recruited throughout the country. The subjects have been genotyped with a genome-wide genotyping chip and exome sequenced. A subset of 897 individuals selected from known population sub-isolates were selected for whole-genome sequencing. Recruitment was done between November 2015 and December 2018.

Findings to date: 5757 (55.2%) had a diagnosis of schizophrenia, 944 (9.1%) schizoaffective disorder, 1612 (15.5%) type I or type II bipolar disorder, 532 (5.1 %) psychotic depression, 1047 (10.0%) other psychosis and for 530 (5.1%) self-reported psychosis at recruitment could not be confirmed from register data. Mean duration of schizophrenia was 22.0 years at the time of the recruitment. By the end of the year 2018, 204 of the recruited individuals had died. The most common cause of death was cardiovascular disease (n=61) followed by neoplasms (n=40). Ten subjects had psychiatric morbidity as the primary cause of death.

Future plans: Compare the effects of common variants, rare variants and copy number variations (CNVs) on severity of psychotic illness. In addition, we aim to track longitudinal course of illness based on nation-wide register data to estimate how phenotypic and genetic differences alter it.

Keywords: Depression & mood disorders; PSYCHIATRY; Schizophrenia & psychotic disorders.

Figure 1

The data collection and processing workflow chart. Additional information is available in online supplemental file 1. hIPSC, human induced pluripotent stem cell.

Figure 2

Sample recruitment by university hospital district. The background colour in parenthesis describes the number of recruited samples relative to the number of individuals living in the area. Individuals have been grouped based on the municipality they live in and each dot has been placed within the municipality in which the subject lives to depict the geographical distribution of the sample.

Figure 3

(A) The mean number of involuntary hospital days by diagnosis group. The means are adjusted for age, sex and recruitment area. The whiskers in the bar chart represent 95% CIs. (B) Density plots of involuntary hospital days on logarithmic x-axis.