Role of dietary and environmental factors in drug abuse.

A review of the literature indicates that a number of food constituents, e.g., dietary sugar, neurotransmitter amino acid precursors and food deprivation, may modulate the development of tolerance and physical dependence as well as influence the self-administration of several drugs of abuse in animals. In particular, the role of palatability of food, involvement of the autonomic nervous system, exposure to cold and nutritional status as well as seasonal cyclical changes is discussed. The effect of the above factors may in part be mediated by precursor modulation of monoaminergic neurotransmitters, modulation of endogenous opioid neurotransmitters in the neuronal terminals of the brain or modulation of endogenous peptides. This paper points to the need of conducting additional research to address this complex and potentially important area of research.