Polygenic risk for schizophrenia predicting social trajectories in a general population sample

Area of Science:

• Psychiatric Genetics
• Developmental Psychology
• Social Psychiatry

Background:

• Investigating polygenic risk for schizophrenia (PRS_SCZ) and its impact on social development in individuals without psychosis.
• Examining if PRS_SCZ associations are specific or shared with other mental disorders like major depression.

Purpose of the Study:

• To determine if PRS_SCZ predicts different social development trajectories in individuals who have not developed psychosis.
• To ascertain if observed associations are specific to schizophrenia risk or also present for general mental disorder risk, such as major depression.

Main Methods:

• Utilized data from the population-based Young Finns Study (n=2377).
• Calculated polygenic risk scores for schizophrenia (PRS_SCZ) and major depression (PRS_DEP).
• Assessed social development via perceived social support, sociability, and family structure from adolescence to middle age.

Main Results:

• High PRS_SCZ predicted lower perceived social support from friends and family, and reduced sociability in individuals without psychosis.
• These effects were particularly noticeable after early adulthood.
• Polygenic risk for major depression (PRS_DEP) did not predict any social development domain.

Conclusions:

• Individuals with high PRS_SCZ, even without psychosis, may prefer solitude and experience less social support.
• Despite similar family structures, high PRS_SCZ is associated with reduced familial support.
• High PRS_SCZ may indicate a later risk phase and diminished functional resilience approaching middle age in non-psychotic individuals.