**2.13 Differential responses to androgens**

Variations in the levels of T and its metabolites, may influence affect and/ or cognition in men. Men who have higher endogenous levels of T have a lower incidence of depression [29]. Conversely, young hypogonadal men, with low endogenous T and DHT levels, are more likely to be diagnosed with an anxiety or depressive disorder, and exhibit decreased performance in cognitive tasks [30, 31].

#### **Figure 10.**

*3α-diol administration increases BDNF levels, but not prostate weight, among wildtype mice, irrespective of 3α-diol levels in the hippocampus. Among ER*β *knockout mice, 3α-diol levels are lower and there is reduced BDNF in the hippocampus (but no change in prostate weight).*

Treatment for these men includes T replacement, which can increase positive, and decrease negative, mood, while improving cognition [32]. However, a different pattern is apparent with use of androgens, such as AAS, among some eugonadal men. AAS are the synthetic variants of T. They are abused by growing numbers of individuals in this country ranging from adolescents, seeking to improve their appearance, to professional athletes attempting to elevate their performance. The costs associated with AAS abuse are substantial. For the individual, AAS abuse is associated with many adverse physical and behavioral consequences. There can be dramatic cognitive and mood changes that are observed among some users of AAS ("'roid rage") and other serious, permanent side effects: kidney and liver damage, liver cancer, heart disease, and hypertension, suppression of T production, testicular atrophy, and gynecomastia. In adolescent males, AAS abuse can hasten the onset of adulthood, promote early baldness, limit stature, and cause premature growth plate closing. Together, these data suggest that there are individual differences in response to androgens that may be related to current hormonal state and/or age.
