Tic severity among youth with Tourette disorder (TD) may be influenced by cognitive control processes, according to results of a randomized, wait list-controlled trial, published in The Journal of Child Psychology and Psychiatry.
Study researchers recruited adolescents (N=53) between the ages of 9 and 14 years with TD or a chronic motor tic disorder at the University of California, Los Angeles between 2007 and 2011. Participants were randomly assigned to receive 8 sessions of manualized behavior therapy over 10 weeks or wait list of equal length.
At baseline and follow-up, study researchers assessed adolescents by the Yale Global Tic Severity Scale (YGTSS), Premonitory Urge for Tics Scale (PUTS), Attention Network Task (ANT), Stop-Signal Task (SST), Go-No Go task, Delis-Kaplan Executive Function System Color-Word Interference Test (D-KEFS CWIT), and a tic suppression task.
Participants had a mean age of 10.93 (standard deviation [SD], 1.62) years, 71.70% were boys, 58.5% were White, 49% had anxiety disorders, 35.8% attention-deficit hyperactivity disorder, and 30% had obsessive-compulsive disorder. The average intelligence was 107.37 (Standard Deviation [SD], 12.49).
At baseline, mean YGTSS total tic score was 25.83 (SD, 6.19), YGTSS impairment score was 25.04 (SD, 8.55), PUTS score was 23.17 (SD, 5.36), ANT incongruent accuracy was 39.62 (SD, 8.64), SST reaction time was 303.83 (SD, 102.96), Go-No Go commission errors was 22.96 (SD, 7.62), D-KEFS CWIT was 10.71 (SD, 2.78), and tic suppression score was 42.94 (SD, 42.72). Youth randomly assigned to receive the therapeutic intervention had higher YGTSS impairment scores (mean 27.70 vs 22.78; P =.04).
Among the active treatment arm, 41.5% displayed a response after behavioral therapy and there was a significant effect of time (F[1,45], 45.79; ƞ2, 0.50; P <.001).
Baseline inhibition/switching score of the D-KEFS CWIT predicted treatment response (b, -0.36; t, -2.35; ƞ2, 0.15; P =.025). Response to behavioral therapy was not predicted by YGTSS total score (t, 1.91; P =.08), PUTS total score (t, -0.56; P =.58), or tic suppressibility (t, -1.07; P =.30).
Stratified by responder and nonresponder status, effect sizes for ANT incongruent accuracy (0.7 vs 0.16), SST reaction time (0.7 vs 0.15), Go-No Go commission errors (0.22 vs 0.03), and D-KEFS CWIT (0.4 vs 0.38) differed, respectively.
Modest enhancing effects on cognitive control processes by the behavioral therapy were observed among responders (d range, 0.4-0.38) compared with nonresponders (d range, 0.4-0.22).
This study may have been limited by only evaluating aspects of cognitive control which were a priori hypothesized to be involved with TD.
The study authors concluded that inhibitory control, not other cognitive control processes, predicted treatment response to behavioral therapy for tic among youth with TD.
McGuire JF, Sturm A, Ricketts EJ, et al. Cognitive control processes in behavior therapy for youth with Tourette’s disorder. J Child Psychol Psychiatry. Published online June 21, 2021. doi:10.1111/jcpp.13470