Polygenic risk for depression predicting temperament trajectories over 15 years - A general population study

Area of Science:

• Behavioral Genetics
• Psychiatry
• Developmental Psychology

Background:

• Depression is associated with distinct temperament traits compared to healthy individuals.
• Temperament traits are stable personality characteristics that develop from early adulthood to middle age.
• Understanding the genetic underpinnings of temperament is crucial for predicting mental health trajectories.

Purpose of the Study:

• To investigate whether polygenic risk for depression (PRS) predicts longitudinal changes in temperament traits.
• To examine the association between PRS and four specific temperament traits: Harm Avoidance, Novelty Seeking, Reward Dependence, and Persistence.

Main Methods:

• Longitudinal analysis of 2212 participants from the population-based Young Finns Study (ages 24-50).
• Polygenic risk for depression (PRS) calculated using genome-wide association study data.
• Temperament traits assessed using the Temperament and Character Inventory across four time points (1997-2012).
• Covariates included depressive symptoms, psychosocial family environment, and socioeconomic factors.

Main Results:

• High PRS was significantly associated with increased Persistence trajectories from early adulthood to middle age (p=0.003).
• PRS did not significantly predict trajectories for Novelty Seeking or Reward Dependence.
• An interaction was found between PRS and depressive symptoms on Harm Avoidance (Anticipatory Worry), with a stronger association in higher PRS individuals.

Conclusions:

• High polygenic risk for major depression may influence temperament trait development independently of diagnosed affective disorders.
• Genetic predisposition for depression is linked to specific longitudinal changes in personality traits, particularly Persistence.
• Findings highlight the complex interplay between genetic factors, temperament, and mental health trajectories.