Alcohol preference ratios during the 5 days of daily 2-h free-choice between alcohol and water were significantly different among the treatment groups [F(4,46) = 8.55, p < 0.001], with significant dose × day interactions [F(16,184) = 1.82, p < 0.05]. Pairwise comparisons using the Fisher’s LSD test revealed that alcohol preference was decreased by clonidine treatment at a dose of 80 µg/kg, relative to treatment with vehicle, on days 1 (p < 0.05), 2 (p < 0.001), 3 (p < 0.001), 4 (p < 0.01), and 5 (p < 0.01). Treatment with clonidine at a dose of 40 µg/kg likewise decreased alcohol preference on days 3 (p < 0.05) and 5 (p < 0.01).
