Verbal fluency
Finally, verbal fluency was assessed using a letter (phonemic), category (semantic) and drug (cannabis) fluency prompts. Participants were required to generate as many words related to each prompt as they could within 1 min. The number of relevant, unique words mentioned was recorded and summed for each variation.Alternate versions of all cognitive tasks were used at each assessment, with the exception of the stop signal task which used a randomised trial design.