Aim – to outline the role of β-endorfin in alcohol addiction syndrome.
Review – β-endrfin, all endogenous opioid peptide, is functionally connected with the mesolimbic reward system playing the most important part in alcohol addiction. The system consists of positive (reward) and negative or aversive (punishment) reinforcement. Imbalance between the two components of the system is responsible for the individual's seeking drugs to restore the balance. One of the ways may involve the endogenous opioid system activation. Clinical observations and laboratory studies have shown that alcohol consumption increases concentration of endogenous opioid peptides. Persons at high risk for alcohol abuse (as determined by their family history), as compared to a low risk group, had by about 50% lower basal plasma β-endorfin concentration. Alcohol consumption results in an increase in this peptide level, compensating for its deficiency. Alcoholics were found to have decreased levels of β-endorfin both in the early and late phase of abstinence. Moreover, laboratory studies indicate differences between alcohol-preferring and alcohol-avoiding animals in β-endorfin levels. Clinical and laboratory observations suggest that certain genetic factors (single-nucleotide polymorphism) may increase the individual's vulnerability to alcohol abuse.
Conclusions – It is possible that decreased β-endorfin plasma concentrations and decreased activity of the opioid system may facilitate alcohol abuse rather than result from alcoholism. This problem may be important in the treatment of patients with alcohol addiction.