Alcohol, alcoholism, and biological rhythms.

Chronobiological rhythms contribute to our understanding of the effect of alcohol and of several features of alcoholism. The observation of infradian periodicities suggests preventive seasonal strategies aimed at reducing the consumption of alcohol and its consequences. Circadian variations in blood alcohol levels and behavioral impairment indicate a complex temporal rhythmicity with both physiological and psychosocial determinants. Circadian differences are noted among possible mediators of susceptibility towards alcoholism. Ultradian patterns may be of prognostic value in assessing risks such as that of relapse during withdrawal from alcohol. Recommendations for future animal and human investigations are suggested.