Driving-related cognitive skills during antidepressant transcranial direct current stimulation: results in a subsample from the DepressionDC trial

Therapeutic transcranial direct current stimulation (tDCS) is a well-tolerated neuromodulatory intervention. However, there are currently no data on its impact on driving skills. Therefore, we conducted a validated assessment of driving-related cognitive skills in participants of the DepressionDC trial, a multicenter, randomized-controlled trial investigating the antidepressant effects of 6-week prefrontal tDCS in patients with major depressive disorder (MDD). Twenty-one patients (12 women, active tDCS, n = 11, sham, n = 10) underwent an assessment of driving-related cognitive skills before and after the intervention. Using a Bayesian analysis approach, we found no group differences between active tDCS and sham tDCS in the pre-post treatment changes for visual perception (estimated median difference: 3.41 [-3.17, 10.55 89%-CI], BF₀₁: 2.1), stress tolerance (estimated median difference: 0.77 [-2.40, 4.15 89%-CI], BF₀₁: 1.6), and reaction time (estimated median difference: 2.06 [-12.33, 16.83 89%-CI], BF₀₁: 6.5). Our results indicate that repeated sessions of a conventional bifrontal tDCS protocol do not negatively impact driving-related cognitive skills in patients with MDD.