Melatonin supplementation as an adjunct to dual-task training: effects on functional capacity and quality of life in Parkinson's disease.

This study assessed the combined effect of 12 weeks melatonin supplementation (5mg/day) and Dual-task training (DTT) on functional capacity and quality of life in patients with Parkinson's disease (PD). Thirty-six participants were randomised into three groups: DTT + melatonin (TMG, n = 13), DTT + placebo (TPG, n = 11), and placebo (PG, n = 12). During bipedal stance, post-intervention centre-of-pressure mean velocity (CoPVm) was lower in TMG and TPG than in PG under both eyes-opened and eyes-closed conditions. During unipedal stance, CoPVm decreased only in TMG under eyes-closed conditions and was lower than in PG. Leg muscle strength was higher in TMG than in TPG and PG, and higher in TPG than in PG at post-intervention. Both training groups demonstrated better motor capacity, freezing-of-gait, and quality-of-life outcomes than PG. Overall, DTT enhanced motor capacity, bipedal static balance, freezing of gait and quality of life, while melatonin provided additional benefits for unipedal static balance and leg strength.