Menstrual cycle phase and responses to drugs of abuse in humans

Researchers have recently become aware of the importance of including women in research, including drug abuse research. With this increased awareness has come an increased scientific interest in the potential influence of menstrual cycle phase on responses to drugs. In this review, we discuss recent studies that have examined subjective and physiological responses to drugs of abuse in relation to menstrual cycle phase. With most of the drugs reviewed, including alcohol, benzodiazepines, caffeine, marijuana, nicotine and opioids, responses to the drugs were not different were inconsistent across cycle phases. However, with psychomotor stimulant drugs, such as amphetamine and cocaine, responses to the drugs were greater during the follicular, compared to the luteal, phase of the cycle. These findings suggest that, consistent with certain pre-clinical findings, circulating levels of ovarian hormones influence the central effects of stimulant drugs in women. With other drugs, the evidence to date suggests that ovarian hormones have modest, if any, effects on responses to abused drugs. We discuss methodological issues relating to inclusion of women with regular menstrual cycles.