Effect of tryptophan depletion on alcohol cue-induced craving in abstinent alcoholic patients.
BACKGROUND
The capacity of alcohol cues to precipitate the desire to drink may be an important determinant of relapse to alcohol use in recovering alcohol-dependent patients. This study evaluated whether attenuation of serotonin synthesis via depletion of its precursor tryptophan reduces the magnitude of cue-induced craving for alcohol in recently abstinent alcoholic individuals.


METHODS
Alcohol-dependent patients (n = 16), 1 to 3 months after detoxification, who exhibited a 20% or greater increase in reported craving when presented with an alcoholic beverage, completed two additional alcohol cue-exposure test days, 1 week apart. Each cue exposure was preceded by administration of a concentrated amino acid drink that resulted in a rapid and significant decline in plasma free tryptophan (active depletion, no tryptophan supplementation) or a similar drink containing tryptophan (placebo depletion). Tests were conducted in a randomized, double-blind fashion.


RESULTS
There were no significant changes in the magnitude of cue-induced craving with active tryptophan depletion compared with placebo.


CONCLUSIONS
These data question the dependence of alcohol cue-induced craving in sober alcoholics on the ongoing synthesis of serotonin.