Patients with major depressive disorder (MDD) who received vortioxetine 10 or 20 mg/d had statistically superior cognitive function in the domains of processing speed, executive functioning, and attention vs patients who received placebo. This post hoc analysis of the FOCUS trial [NCT01422213]—as presented in a poster from Søren Lophaven, PhD, H. Lundbeck A/S, Copenhagen, Denmark, and colleagues—used the Digit Symbol Substitution Test to assess cognitive function.

Patients aged 18 to 65 years who had recurrent MDD as classified by the DSM-IV-TR were enrolled in the multinational, randomized, double-blind, placebo-controlled FOCUS study. Patients who had a current major depressive episode (MDE) of ≥ 3 months and a Montgomery-Åsberg Depression Rating Scale total score ≥ 26 at both screening and baseline visits were eligible. The patients were randomized 1:1:1 to vortioxetine 10 mg/d (n = 195), vortioxetine 20 mg/d (n = 207), or placebo (n = 196) for 8 weeks of double-blind treatment.

Both doses of vortioxetine were statistically superior to placebo for patients aged ≤ 50 years and > 50 years (all P < .01) and regardless of educational level or working status (all P < .05). Both doses were also statistically superior in both sexes, though with stronger significance in women (P < .001) than in men (P < .01).

Both doses were statistically superior to placebo for patients whose body mass index (BMI) was < 25 (n = 233; P < .01 for 10 mg/d and P < .001 for 20 mg/d), whereas only vortioxetine 20 mg/d was statistically superior to placebo for patients whose BMI was ≥ 25 and < 30 (n = 202; P < .05). In obese patients (BMI ≥ 30; n = 156), vortioxetine did not reach statistical significance with this smaller group.

All patients had ≥ 1 MDE, and both doses of vortioxetine were statistically superior to placebo for all patients (n = 591, P < .001 for both doses), for patients who had ≥ 2 MDEs (n = 354, P < .001 for both doses), and for patients who had ≥ 3 MDEs (n = 186, P < .01 for 10 mg/d and P < .001 for 20 mg/d). For patients who had ≥ 4 MDEs (n = 103), only vortioxetine 20 mg/d was statistically superior to placebo (P < .05).

Duration of a current MDE did not affect the effectiveness of vortioxetine; both doses of vortioxetine were statistically superior to placebo for all patients whose current MDE was ≥ 3 months (n = 591), ≥ 4 months (n = 429), or ≥ 5 months (n = 276; P < .001 for these MDE lengths). Both doses of vortioxetine were also statistically superior to placebo for patients whose current MDE was ≥ 6 months (n = 202; P < .01 for 10 mg/d and P < .001 for 20 mg/d).

Overall, Digit Symbol Substitution Test scores were statistically superior with vortioxetine 10 and 20 mg/d vs placebo, indicating improved executive function, processing speed, and attention in treated patients.