Drugs of abuse and the circadian rhythm.

I am interested in drugs of abuse and the circadian rhythm. Currently, I am investigating the role of the circadian rhythm on the reinforcing properties of methamphetamine. Anecdotal evidence suggests that people self-administer illicit substances at night. It has always been assumed that this is for reasons such as convenience and privacy. However, diurnal rhythms in biological processes may also play a role. My research will examine the biological and behavioral influence of circadian rhythms on drug-taking behavior.