Endogenous substances resulting from interactions between alcohol and possibly opioid metabolites and neurotransmitters (dopamine, indolamines) are mediators of the pathochemical process towards dependence. Beta-carbolines are increased in alcoholics and--according to our own results--in heroin-addicts. Still unclear is the impact of other psychopathological disturbances like states of anxiety or depression; unclear is also, if it has to be interpreted as state, trait or residual marker of the dependence syndrome.