DOES A RELATIONSHIP EXIST BETWEEN THE QUALITY OF STRESS AND THE MOTIVATION TO INGEST ALCOHOL

Previous experimental findings on the relationship between emotional s tress and motivation to ingest alcohol are contradictory. To obtain in formation about this relationship we tested the effects on alcohol con sumption in rats subjected to two types of chronic unavoidable stresso rs, intermittent immobilization and social isolation, which differ in their influence on the functional state of the endogenous opioid syste m. To characterize the nature and magnitude of the stress induced by t hese stressors, we measured their effects on functional parameters whi ch have a close relationship to the regulatory influence of endogenous opioid peptides (endogenous opioid dependence, pain sensitivity, bloo d pressure). Our investigations have shown that chronic intermittent i mmobilization, which induced development of endogenous opioid dependen ce, presumably due to activation of endogenous opioid systems, did not produce increased alcohol consumption. On the contrary, chronic socia l isolation, which did not induce development of endogenous opioid dep endence, was followed by a significant increase in alcohol consumption . It is concluded that not all types of stress produce increased alcoh ol consumption, but that the effect on the endogenous opioid system ma y be a decisive factor in determining whether a stressor produces incr eased alcohol consumption.