Resting state functional connectivity in adolescent synthetic cannabinoid users with and without attention-deficit/hyperactivity disorder

Objective Synthetic cannabinoids (SCs) have become increasingly popular in recent years, especially among adolescents. The first aim of the current study was to examine resting-state functional connectivity (rsFC) in SC users compared to controls. Our second aim was to examine the influence of comorbid attention-deficit/hyperactivity disorder (ADHD) symptomatology on rsFC changes in SC users compared to controls. Methods Resting-state functional magnetic resonance imaging (fMRI) analysis included 25 SC users (14 without ADHD and 11 with ADHD combined type) and 12 control subjects. Results We found (i) higher rsFC between the default mode network (DMN) and salience network, dorsal attention network and cingulo-opercular network, and (ii) lower rsFC within the DMN and between the DMN and visual network in SC users compared to controls. There were no significant differences between SC users with ADHD and controls, nor were there any significant differences between SC users with and without ADHD. Conclusions We found the first evidence of abnormalities within and between resting state networks in adolescent SC users without ADHD. in contrast, SC users with ADHD showed no differences compared to controls. These results suggest that comorbidity of ADHD and substance dependence may show different rsFC alterations than substance use alone.Ege University Science and Technology Application and Research CenterEge University [2015 EGEBAM 001]; TUBITAK-BIDEB 2219-International Postdoctoral Research Fellowship Programme [53325897-115.02-39691]This research was funded by Ege University Science and Technology Application and Research Center (grant number 2015 EGEBAM 001) which had no role in the design of the study, collection and analysis of data and decision to publish. N. Zorlu received financial support from TUBITAK-BIDEB 2219-International Postdoctoral Research Fellowship Programme (Grant no. 53325897-115.02-39691) for this study