Transcranial Direct Current Stimulation May Improve Motor Learning in Nonclinical Psychosis
In patients with nonclinical psychosis, the rate of learning was significantly improved following active tDCS compared with sham tDCS.
According to the results of a study published in Schizophrenia Bulletin, cerebellar transcranial direct current stimulation (tDCS) improved the rate of motor learning in participants with nonclinical psychosis at a rate comparable with participants without nonclinical psychosis.
In this double-blind crossover study, 24 participants (mean age 19.05; range 18-22) with nonclinical psychosis based on the Community Assessment of Psychiatric Experiences positive symptom dimension questionnaire and 18 control participants were randomly assigned to receive 25 minutes of anodal cerebellar tDCS or sham cerebellar tDCS. After tDCS, procedural learning performance was evaluated based on the mean time of completion of 3 trials of a pursuit rotor task. All participants returned 1 week later and underwent the corresponding treatment before completing the pursuit rotor task.
No interaction between treatment group and procedural learning performance was reported in the control participants (P =.225). In contrast, a significant interaction between treatment group and performance on the pursuit rotor task was reported in participants with nonclinical psychosis (P =.010).
After sham tDCS, the control group performed better on the pursuit rotor task compared with the group with nonclinical psychosis (P =.019). After active tDCS, no significant difference was reported between the 2 groups in performance on the pursuit rotor task (P =.215).
In patients with nonclinical psychosis, the rate of learning was significantly improved following active tDCS compared with sham tDCS (P =.046).
The study investigators concluded that tDCS “may be an important tool for further improving our understanding of psychosis as well as for designing targeted treatments.” They added that the study “also highlights that studying [nonclinical psychosis] individuals can be useful in understanding prevention of and intervention for psychotic disorders.”
Gupta T, Dean DJ, Kelley NJ, Bernard JA, Ristanovic I, Mittal VA. Cerebellar transcranial direct current stimulation improves procedural learning in nonclinical psychosis: a double-blind crossover study [published online December 30, 2017]. Schizophr Bull. doi:10.1093/schbul/sbx179