Psychological Medicine; Cambridge Vol. 48, Iss. 11, (Aug 2018): 1920-1920. DOI:10.1017/S0033291718000776
The publisher apologizes for an error found in the abstract of the above article (Janssen, L., Kan, C., Carpentier, P., Sizoo, B., Hepark, S., Schellekens, M., … Speckens, A. (2018)). “Showed a ⩽30% reduction of ADHD symptoms” should be corrected to “showed a ⩾30% reduction of ADHD symptoms”.