A cohort study spanning 18 years found that individuals with persistent common mental disorders (CMDs) such as anxiety or depression show personality maturation later than the general population, with elevated neuroticism persisting into middle age, though decreasing over time. The study was published in Scientific Reports.
The Study
The research analyzed data from 1,943 participants of the Victorian Adolescent Health Cohort Study (1992-2021), tracking personality traits (using NEO-FFI) and mental health (using GHQ-12, CIS-R, CIDI) from adolescence to age 42.
Participants were grouped by their history of common mental disorders (CMD) and substance use:
- None
- Adolescent-only
- Adulthood-only
- Both (persistent)
Key Findings
General Population Trends
In the general population, conscientiousness and agreeableness increased over time, while extraversion, openness, and neuroticism decreased.
Persistent CMD Group
- Individuals with persistent CMDs showed greater increases in agreeableness (SMD = 0.4) and greater decreases in neuroticism (SMD = -0.3).
- Despite these improvements, their neuroticism remained higher than those without CMDs at middle age.
Substance Use Problems
- Adolescent-limited substance use was linked to decreased openness.
- Persistent or adulthood-only substance use was associated with decreased neuroticism.
"The authors suggest clinicians may need to provide additional support for emotionally vulnerable individuals, as personality maturation may occur on a different timeline."
Limitations
The researchers note several important caveats:
- Personality was assessed only twice, making it impossible to pinpoint the exact timing of changes.
- All traits were self-reported.
- Missing data was higher for CMD and substance use classifications.
- The overlap between neuroticism and anxiety/depression symptoms was considered in the analysis.
- Regression to the mean may partly explain the observed declines in neuroticism.
The authors emphasize that the findings are descriptive and not causal, and call for further studies with more frequent assessments.