Sexual Motivation (Desire): Problems with Current Preclinical and Clinical Evaluations of Treatment Effects and a Solution.

There has been an extensive search for efficient pharmacological treatment of female sexual interest/arousal disorder and other sexual dysfunctions. However, available treatments have met limited success, except for the drugs used for treating erectile deficiency. A possible reason for this may be that both the preclinical and clinical evaluation of treatment effects have been inadequate. The present literature review shows that the intensity of sexual approach behaviors in non-human animals appears to be predictive of clinical effect whereas the traditional studies of copulatory behaviors and associated motor patterns have questionable predictive power regarding effects on human sexual desire. In clinical studies, it is essential to include the unconscious components of sexual motivation in any approach to its quantification. This basic fact is incompatible with the use of self-reports for evaluating treatment effects on motivation. Genital responses to sexual incentives are automatic and therefore outside of volitional control and can, therefore, provide unbiased estimates of the intensity of sexual motivation. These responses may be objectively quantified. Tests for implicit sexual motivation must also be used for capturing unconscious mental components. Including the unconscious components of sexual motivation as well as of objective measures of genital responses in clinical studies may improve evaluations of the effectiveness of drug treatment of low sexual interest/arousal disorder. In preclinical studies, predictive validity can be improved by quantifying sexual approach behaviors rather than copulatory behavior. The paradigm shift suggested here may finally allow for the discovery of efficient treatments for some sexual dysfunctions.