Since depression entails not only dramatic personal disruption but also a huge amount of medical and socioeconomic burden, slowness of antidepressant action and difficulties to attain remission are entangled issues to be solved. Given the controversial previous findings with enhancing strategies such as pindolol, we examined whether the speed of selective serotonin reuptake inhibitor (SSRI) action can be truly accelerated with optimized pindolol dosage. Additionally, we aimed at elucidating whether pindolol benefits emerge, particularly in a population with nonresistant depression. Thirty outpatients with major depressive disorder (DSM-IV criteria) recruited between December 2002 and November 2005 were randomly assigned to receive citalopram + pindolol (5 mg tid) or citalopram + placebo for 6 weeks in a double-blind randomized clinical trial. A meta-analysis of randomized controlled trials of pindolol augmentation in patients with nonresistant depression was also performed. Outcome criteria were based on the 17-item Hamilton Depression Rating Scale. For the meta-analysis, efficacy was assessed by the number of treatment responders at 2 weeks and 4-6 weeks. Clinical trial outcomes: Repeated-measures analysis of variance showed a significant group-by-time interaction (P = .01). Cumulative percentage showed a trend for sustained response (odds ratio [OR] = 2.09; 95% CI, 0.914-4.780; P = .08) and a well-defined increased likelihood of sustaining remission (OR = 5.00; 95% CI, 1.191-20.989; P = .03) in pindolol receivers. Median survival time until first response was 65% less in the pindolol group (22 days vs 30 days; P = .03). The negative binomial regression model yielded different rates of response per person-day for pindolol and placebo groups (7.6% vs 4.7%, respectively; P = .03). Meta-analysis: Outcome favored pindolol at 2 weeks' time (relative risk [RR] = 1.68; 95% CI, 1.18-2.39; P = .004) and also at 4-6 weeks' time (RR = 1.11; 95% CI, 1.02-1.20; P = .02). Present findings represent further evidence of the acceleration and enhancement of efficacy with pindolol administered together with SSRIs, displaying a quicker and more pronounced decrease of symptoms in patients with nonresistant major depressive disorder. clinicaltrials.gov Identifier: NCT00931775.