Plasma GABA levels correlate with aggressiveness in relatives of patients with unipolar depressive disorder

Plasma gamma-aminobutyric acid (GABA) levels are decreased in some patients with depression, mania and alcoholism. Medications which increase plasma G ABA improve symptoms of mood disorders and can decrease aggression. We exam ined the relationship between plasma GABA and aggressiveness on the Buss-Du rkee Hostility Inventory in 77 psychiatrically healthy adults. In subjects selected for having a first-degree relative with primary unipolar depressiv e disorder (FH + , n = 33), plasma GABA was negatively correlated with aggr essiveness (beta = -0.338, P = 0.036), as was age (beta = -0.483, P = 0.005 ). A relationship between plasma GABA levels and aggressiveness was not obs erved in subjects with no such family history (FH - , n = 44). Moreover, FH + subjects had significantly lower plasma GABA concentrations than FH- sub jects. These data suggest that low GABA levels may correlate with some aspe cts of aggressiveness and may be genetically regulated. (C) 2001 Elsevier S cience Ireland Ltd. All rights reserved.