The role of tactile sensitivity in female sexual dysfunction

Convergent evidence suggests tactile sensitivity may be associated with sexual dysfunction in women. Both tactile sensation and female sexual functioning are affected by variations in estrogen levels, sympathetic nervous system activation, and vascular functioning. In addition, antidepressant-induced sexual dysfunction (with selective serotonin reuptake inhibitors such as fluoxetine) may be mediated by changes in tactile sensation. Serotonin is active in several peripheral mechanisms likely to affect sexual functioning such as vasoconstriction and dilation, smooth muscle contraction, and innervation of the genitals. Two studies were conducted to examine these hypotheses. In Study 1, tactile sensitivity was examined on the index finger and lower lip in women with Female Sexual Arousal Disorder (FSAD; n = 15), Female Orgasm Disorder (FOD; n = 17), and normally functioning women (n = 17). Finger and lip threshold were significantly associated with FSAD versus control women, and finger threshold with severity of FSAD. Finger and lip threshold were not significantly associated with FOD versus control women, or severity of FOD. In Study 2, tactile sensitivity was examined at baseline (pre-medication), week 1, week 4, and week 8, in clinically depressed women, 12 of whom received fluoxetine treatment and 13 of whom did not. Fluoxetine treatment resulted in decreased orgasm functioning, but not sexual desire or arousal functioning. Analyses indicated that fluoxetine-induced sexual changes were not mediated by tactile sensation. Consistent with previous findings, an independent association was found between sexual arousal functioning and finger sensation. Novel to this study, an independent association was found between sexual desire and finger sensation. Findings from the two studies suggest that tactile sensation may serve as a physiological assessment tool for FSAD. Future studies will need to examine whether tactile sensation measurements differentiate between subtypes of FSAD, and other types of sexual disorders, such as Hypoactive Sexual Desire Disorder. Future studies will also need to examine the association between sexual functioning and other aspects of tactile sensation, such as vibrotactile, temperature, and pain sensation, and nerve conduction velocity, on both genital and non-genital regions of the body.