Repetitive transcranial magnetic stimulation alleviates psychomotor slowing from psychosis

Key takeaways:

• Of 22 participants in each arm, there were 15 responders in the rTMS group vs. seven in the sham group.
• There were four responders in the no treatment group and 10 responders after delayed 1-Hz rTMS treatment.

Three weeks of 1-Hz repetitive transcranial magnetic stimulation effectively alleviated psychomotor slowing among people with schizophrenia spectrum disorder, according to a study published in JAMA Psychiatry.

“Psychomotor slowing often comes with multiple disadvantages, such as cognitive impairment, sedentary behavior, cardiometabolic risks, poor quality of life, lower subjective well-being and impaired functioning,” Sebastian Walther, MD, head of the outpatient clinic at the University of Bern Hospital of Psychiatry and Psychotherapy in Bern, Switzerland, and colleagues wrote. “No specific treatment is available to target psychomotor slowing.”

The four-arm double-blind randomized trial took place from March 2019 to August 2022 and involved 88 participants (51% men; mean age, 36.3 years) with schizophrenia spectrum disorders and severe psychomotor slowing. Researchers assigned 22 participants each to one of four treatments: 1-Hz repetitive transcranial magnetic stimulation (rTMS), intermittent theta burst stimulation (iTBS), sham treatment or no treatment. Each group received 15 sessions of their respective treatment over a 3-week period except for the no-treatment group, which underwent rTMS for 3 weeks after a second baseline assessment at week 3.

Researchers used scores from the Salpêtriére Retardation Rating Scale (SRRS) to compare the results from each treatment. All study participants were required to have a minimum score of 15 out of 60 to be eligible for the study, with a mean baseline SRRS score of 24 (standard deviation, 5.9). Researchers considered participants to be responders to treatment if they experienced a 30% or greater score reduction by the end of week 3.

Sixty-nine of the patients finished treatment and completed week-3 assessments, including 16 in the rTMS group, 18 in the iTBS group, 19 in the sham group and 16 in the no-treatment group. The most common reason for discontinuing treatment was withdrawal of consent.

The rTMS group had the highest response rate, with 15 responders out of 22 participants (68%), compared with eight responders (36%) in the iTBS group, seven responders (32%) in the sham group and four responders 18% in the no-treatment group (P = .007).

Later receipt of rTMS in the no-treatment group resulted in 10 responders (63%) after 3 weeks of treatment as well.

Compared with the rTMS group, the odds ratios for treatment response were 0.13 (95% CI, 0.02-0.65) for the sham group, 0.12 (95% CI, 0.02-0.61) for the iTBS group and 0.04 (95% CI, 0.01-0.22) for no treatment.

“As hypothesized, 1-Hz stimulation ameliorated psychomotor slowing,” the researchers wrote. “This study corroborates the previous transdiagnostic randomized clinical trial on add-on daily 1-Hz rTMS in a new sample of patients with schizophrenia spectrum disorders.”