Non-right-handedness and Free Serum Testosterone Levels in Detoxified Patients with Alcohol Dependence

Aims: The influence of testosterone on the extent of hemispheric dominance has been discussed not just during the first two trimesters of pregnancy but also later in life. An increase in free serum testosterone levels has been found during and after the detoxification phase of patients with alcohol dependence. Methods: In 250 participants (125 men and 125 women) with alcohol dependence immediately after the direct withdrawal phase (Day 21) and in 250 healthy age- and gender-matched participants, free testosterone in the serum was determined and handedness was assessed as a peripheral marker of central hemispheric dominance. Results: Patients with alcohol dependence were 2.7-fold (odds ratio, OR: 2.66; 95% confidence interval, CI: 1.62–4.38) and men 4.1-fold (OR: 4.12; 95% CI: 2.44–6.98) more likely to be non-right-handed (NRH). In addition to male gender, non-right-handedness and alcohol dependence contributed statistically significantly to higher serum testosterone levels. Testosterone values of patients with alcohol dependence differed significantly between the four different Lesch subtypes; in particular, participants with alcohol dependence classified according to Lesch subtype IV were found to have significantly higher serum testosterone levels (F = 20.5; P < 0.001) when compared to participants classified according to Lesch subtypes I–III. Conclusions: An alteration of hemispheric dominance and thus an exogenously modifiable neuronal plasticity may be demonstrated directly on a population at risk.