Increased alcohol consumption in rats after subchronic antidepressant treatment

The use of antidepressants for alcoholism in humans has been a matter of controversy in recent years. Despite the existence of an important co-morbidity for depression and alcoholism, some studies suggest that the use of antidepressants could worsen the prognosis of alcoholism. However, there is a lack of studies in animal models exploring this phenomenon. In the present study, we show how the 15-d treatment with fluoxetine (10 mg/kg) or venlafaxine (50 mg/kg) affected alcohol deprivation effect (ADE) and subsequent alcohol consumption. Initially, fluoxetine reduced ADE and venlafaxine did not affect it. However, in the following days, both antidepressants increased alcohol consumption, an effect that was found to last at least 5 wk. Fluoxetine treatment was shown to cause a locomotor sensitized response to a challenge dose of amphetamine (0.5 mg/kg), indicating the presence of a supersensitive dopaminergic transmission. In summary, antidepressant treatment may increase alcohol consumption in rats after a period of alcohol deprivation and this could be related to alterations in the reward circuitry. This finding confirms in an animal model previous reports in humans that may limit the use of antidepressants for alcoholism.