Objective: This study analyses the association between impulsive-disinhibited personality traits and the androgen receptor CAG and GGN repeat polymorphisms in both inmates and control samples.
Methods: We used two samples: 153 inmates (mean age= 33.31 years; standard deviation: 8.6; range: 20–63) and 108 controls (mean age= 26.71 years; standard deviation: 9.68; range: 17–53). A disinhibited personality construct was measured using the following personality scales: Sensation Seeking, Aggression-Hostility, Psychoticism, Sensitivity to Reward, Novelty Seeking and Impulsivity. A factor analysis of the six scales provided a normalized z index that was taken as a measure of impulsive-disinhibited personality.
Results: Our data show that inmates carrying CAG short and GGN long haplotype group (short–long haplotype) obtained higher scores on all personality scales. Differences were found for the Impulsive Sensation-Seeking scale (age-adjusted multivariate analysis, P<0.016) and z index (P<0.036). When comparing extreme groups in the impulsive-disinhibited personality index (taking the 75th percentile as a cut-off), carriers of the short–long haplotype were more prevalent in the extreme high group (30 vs. 10%: unadjusted odds ratio=3.8; 95% confidence interval=1.5–9.8; age-adjusted odds ratio=4.4; 95% confidence interval=1.6–12; P<0.004).
Conclusion: Our findings suggest that the androgen receptor CAG and GGN polymorphisms might influence impulsive-disinhibited personality traits.