N of 1 study: amantadine for the amotivational syndrome in a patient with traumatic brain injury.

Severe amotivation, apathy, and abulia, significantly retard rehabilitation following traumatic brain injury. Preliminary, uncontrolled research has suggested possible benefit with amantadine for this behavioural syndrome. This N of 1, double-blind, placebo-controlled study employed amantadine 100 mg three times daily in one such patient. Therapists and nurses completed inventories scoring efforts towards initiation of therapeutic activities during each session, progress in therapy, and participation in therapy. Four treatment periods (two active medication, two placebo), of 2 weeks duration, were completed. Across four therapists, and for both treatment pairs, the average effect score increased from 0.86 on placebo to 1.74 on amantadine (possible range 0-6, 3 = 'average'). There were no side-effects. The study suggests possible benefit with amantadine for patients with amotivational syndrome after traumatic brain injury; a randomized clinical trial appears warranted and required.