Objectives: Most previous studies evaluating use of methylphenidate following traumatic brain injury (TBI) have been conducted many years post-injury. This study evaluated the efficacy of methylphenidate in facilitating cognitive function in the inpatient rehabilitation phase.
Methods: 40 participants with moderate-severe TBI (Mean = 68 days post-injury) were recruited into a randomised, crossover, double-blind, placebo controlled trial. Methylphenidate was administered at a dose of 0.3mg/kg bd and lactose in identical capsules served as placebo. Methylphenidate and placebo administration was randomized in a crossover design across six sessions over a two week period. Primary efficacy outcomes were neuropsychological tests of attention.
Results: No participants were withdrawn due to side-effects or adverse events. Methylphenidate significantly increased speed of information processing on the Symbol Digit Modalities Test (95% CI .30 to 2.95, Cohen’s d = .39, p = .02), Ruff 2 & 7 Test – Automatic Condition (95% CI 1.38 to 6.12, Cohen’s d = .51, p = .003), Simple Selective Attention Task (95% CI -58.35 to -17.43, Cohen’s d = .59, p = .001) and Dissimilar Compatible (95% CI -70.13 to -15.38, Cohen’s d = .51, p = .003) and Similar Compatible (95% CI -74.82 to -19.06, Cohen’s d = .55, p = .002) conditions of the Four Choice Reaction Time Task. Those with more severe injuries and slower baseline information processing speed demonstrated a greater drug response.
Conclusions: Methylphenidate enhances information processing speed in the inpatient rehabilitation phase following TBI. This trial is registered with the Australian New Zealand Clinical Trials Registry (12607000503426).