Androgens in Health and Disease.pdf - E Library

Chapter 14/Androgens and Sexual Function 283
2. Those women who are behaviorally responsive to T respond to levels of T that would be
totally ineffective in men, This greater sensitivity to T in women is apparent in behavioral
and other central nervous system (CNS) responses and is possibly less marked in the
anabolic and skin effects of T.
3. Men and women may differ in the relationship between affect and sexuality. Although
studies of androgen withdrawal and replacement in men show that mood, energy, and
well-being are affected, the impact on these variables appears to be more influential and
predictable in women than in men. The reasons for this are poorly understood. In general,
the relationship between mood and sexuality has received very little attention. Conventional
wisdom holds that sexual interest and, to some extent, responsiveness typically
goes down in negative mood states. However, current research on this topic at the Kinsey
Institute (131a) shows that a substantial minority of men experiences an increase in
sexual interest when in negative mood states, to some extent with depression but more
often with anxiety or stress. This paradoxical pattern is more likely in younger men. Our
preliminary results with women suggest that whereas this paradoxical pattern does occur,
it is less common than in men. The possible mechanisms involved in this relationship are
beyond the scope of this chapter, but are, in any case, little understood. Whether the
effects of T are involved remains uncertain.
4. A fundamental difference in male and female mechanisms of androgen production may
be relevant. More than 90% of testosterone in the male is produced by the testes. By
contrast, a substantial proportion of androgen production in women is from the adrenal
glands and, hence, increased adrenal androgens can be expected in states associated with
increased adrenal activity, such as anxiety, stress, or depression. There is limited evidence
of androgen levels in such mood states, but they indicate that an increase in T is
possible (132–134). In the male, somewhat more attention has been paid to T levels in
negative mood states; overall, the evidence is inconsistent, showing no change or a
decrease, and with uncertainty in most studies whether the decrease is a cause or a
consequence of the negative mood (135). No evidence of an increased T in negative mood
states in men has been found. Thus, it seems unlikely that the paradoxical increase in
sexual interest in some men when in negative mood states could be caused by increased
T, but this possibility needs to be ruled out. In women, it should be possible to establish
whether those who report an increased sexual interest in negative mood states have a
greater increase in their T levels than those who do not. In any case, this added complexity
in women could be contributing to the overall confused picture.
5. The evidence is suggestive that testosterone–behavior relationships are more easily
obscured by other psychological mechanisms in women than is the case for men, although
this comparison warrants direct study. If so, this would imply that the hormone
effects are more robust or predominant in the male.
6. In the male, the evidence supports the idea of a threshold above which increased T levels
have little behavioral effect, and below which signs of androgen deficiency are likely to
occur. The evidence does not support this same threshold concept in women. The most
convincing behavioral effects of the administration of exogenous androgens involves
supraphysiological levels; although in a number of studies, sensitivity to these levels
appears to decrease over time. On the other hand, it remains possible that signs of androgen
deficiency will occur if circulating levels of T fall too low, the critical level depending
on a particular woman’s sensitivity, although the effects of such deficiency on the
woman’s sexuality may be obscured by other psychological factors in the woman’s life.
7. If the effects of T on genital response in males is comparatively subtle and complicated by
other factors impacting on genital response, this would appear to be even more so in women.