In addition, there is a social taboo against women other than prostitutes initiating sexual contact. This has its practical aspects, since men are thought to be intimidated by women who initiate sex. If a woman truly does want sex, her best ploy may be to feign disinterest in it.
In current Western permissive societies, men are admitting in greater numbers that they are not always interested in sex. At the same time, more women feel that they should not put up with unsatisfactory sexual relations and lie about their dissatisfaction. So more women are initiating sexual contact with their male partners, who are sometimes openly disinterested. This may reduce both male and female sexual drive further.
Some antidepressant drugs cause loss of female libido.