This article is more than 5 years old. Information may no longer be current.

Adolescent personality plays role in risk for adult mental illness

Nationwide study results indicated low social maturity, mental energy and emotional stability in late adolescence were associated with subsequent psychiatric disorders among men.

“Kraepelin first raised the question of whether specific premorbid personality traits reflect an early stage of illness or a genetic disposition to serious mental illness. However, our understanding of personality as an independent risk factor for [serious mental illness] remains limited,” Joseph F. Hayes, MB, ChB, MSc, of University College London, and colleagues wrote. “Recently, a polygenic basis for neuroticism and a shared genetic architecture with schizophrenia has been found, with inconsistent results for bipolar disorder. Furthermore, polygenic risk scores for bipolar disorder are associated with extraversion. This research has prompted renewed interest in the association between personality and [serious mental illness].”

To assess associations between adolescent personality domains of social maturity, mental energy and emotional stability with later serious mental illness diagnosis, researchers conducted a longitudinal cohort study of Swedish male military conscripts aged 18 or 19 years from January 1974 through December 1997 (n = 1,017,691).

Overall, 4,310 men developed bipolar disorder; 784 developed schizoaffective disorder; 4,823 developed schizophrenia; and 5,013 developed other nonaffective psychoses.

Researchers found a dose-dependent inverse association between schizophrenia and low social maturity (HR = 1.61; 95% CI, 1.48-1.74), low mental energy (HR = 1.34; 95% CI, 1.24-1.44) and low emotional stability (HR = 1.51; 95% CI, 1.4-1.63), after adjustment.

Bipolar disorder was associated with high (HR = 1.21; 95% CI, 1.09-1.35) and low (HR = 1.12; 95% CI, 1.01-1.25) social maturity and low emotional stability (HR = 1.62; 95% CI, 1.46-1.78).

Low emotional stability (HR = 1.53; 95% CI, 1.26-1.85) was associated with schizoaffective disorder.

“This study indicates clearly and robustly that low social maturity, mental energy, and emotional stability are associated with nonaffective psychotic illnesses in general. However, individuals who developed bipolar disorder had different patterns of these personality traits. Personality dimensions may therefore be useful in understanding [serious mental illness] endophenotypes, and future research should focus on shared genetic influences on personality and [serious mental illness],” the researchers concluded. – by Amanda Oldt

Disclosure: The researchers report no relevant financial disclosures.