Mommaerts JL, Beerens G, Van den Block L, Soetens E, Schol S, Van De Vijver E, Devroey D. Influence of methylphenidate treatment assumptions on cognitive function in healthy young adults in a double-blind placebo-controlled trial. Psychol Res Behav Manag. 2013 Volume 2013:6;65-74.
Eerste auteur: Mommaerts JL
Jaar: 2013
Type: Publicatie
Abstract:
Objective: Increasing numbers of students use stimulants such as methylphenidate (MPH) to improve their study capacity, making them prone to subsequent prolonged drug abuse. This study explored the cognitive effects of MPH in students who either assumed they received MPH or assumed they received a placebo.
Methods: In a double-blind randomized placebo-controlled trial with between-subjects design, 21 students were subjected to partial sleep deprivation, receiving no more than four hours sleep the night before they were tested. In the morning, they were given either a placebo or 20 milligrams of MPH. They then performed free recall verbal tests and Go/No-Go tasks repeatedly, their moods were evaluated using Profile of Mood States (POMS), a Visual Analogue Scale (VAS) measured tiredness, and their vigilance was assessed.
Results: No significant differences were found between those subjects who received MPH and those who received a placebo. However, significant differences were found between subjects who assumed they had received MPH or had no opinion, and those who assumed they had received a placebo. At three minutes, one hour and one day after memorizing 10 lists of 20 words, those who assumed they had received MPH recalled 54%, 58% and 54% of the words respectively, whereas those who assumed they had received a placebo only recalled 35%, 37% and 34%.
Conclusion: Healthy, partially sleep-deprived young students who assume they have received 20 milligram of MPH experience a substantial placebo effect that improves consolidation of information into long-term memory. This is independent of any pharmacological effects of MPH, which had no significant effects on verbal memory in this study. This information may be used to dissuade students from taking stimulants such as MPH during examination periods, thus avoiding subsequent abuse and addiction.
Trefwoorden: methylphenidate, treatment assumption, placebo, cognitive functioning