Calculated bioavailable testosterone levels and depression in middle-aged men

SummaryBackgroundThe association between circulating total testosterone (TT) levels and depressive symptoms remains unclear. We sought to determine the relationship between physiologically active bioavailable testosterone (BT) and depressive symptoms in middle-aged men with and without major depressive disorder (MDD).MethodsWe assessed and compared calculated BT levels in two groups of middle-aged men (40–65 years): untreated subjects meeting DSM-IV-TR-defined criteria for a major depressive episode as part of major depressive disorder (N=44) and a matched non-depressed control group (N=50).ResultsDepressed men had lower mean BT levels (3.51±1.69 vs. 4.69±2.04 nmol/L; p=0.008) and TT levels (11.94±4.63 vs. 17.64±1.02 nmol/L; p<0.001) when compared to the control group. Biochemical hypogonadism (i.e., BT level⩽2.4 nmol/L or TT level⩽12.14 nmol/L) was also more prevalent in depressed men vs. non-depressed controls (34% vs. 6%, p<0.001; 61% vs. 14%, p<0.001, respectively).ConclusionsChanges in physiologically active BT concentration may be a vulnerability factor for depressive symptoms in middle-aged depressed men.