Effects of prolonged selective 5-HT reuptake inhibitors citalopram (A) and paroxetine (B) on the development of L-DOPA-induced abnormal involuntary movements (AIMs). L-DOPA-naïve rats were treated with vehicle, citalopram (3 or 5 mg/kg, s.c.), or paroxetine (0.5 or 1.25 mg/kg, s.c.) 30 min prior to vehicle or L-DOPA (6 mg/kg, s.c.) + benserazide (15 mg/kg, s.c.) daily for 22 days. ALO AIMs were evaluated for 3 h after L-DOPA on days 1, 8, 15, and 22. Values are expressed as medians (AIMs + median absolute difference; M.A.D.). Significant differences were determined by non-parametric Kruskal-Wallis ANOVAs at each test day with Mann-Whitney post-hocs. * p < 0.05 vs. Vehicle + L-DOPA, + p < 0.05 vs. Citalopram (5) or Paroxetine (1.25) + L-DOPA.