Overcoming Psychomotor Slowing in Psychosis (OCoPS-P)

Psychomotor slowing is a major problem in psychosis. Aberrant function of the cerebral motor system is linked to psychomotor slowing in patients, particularly resting state hyperactivity in premotor cortices. A previous clinical trial indicated that inhibitory stimulation of the premotor cortex would reduce psychomotor slowing. The current study is further exploring this effect in a randomized, placebo-controlled, double-blind design with three arms of transcranial magnetic stimulation and measures of brain imaging and physiology prior to and after the intervention.

As psychomotor slowing is a major problem in schizophrenia, contributing to poor functional outcome, and as no current treatment is effectively targeting psychomotor slowing, this study seeks to test noninvasive brain stimulation to overcome psychomotor slowing. Previous studies documented an aberrant increase of neural activity within the supplementary motor area (SMA) in patients with schizophrenia who had psychomotor slowing. Furthermore, a pilot study in major depression and schizophrenia indicated that inhibitory 1 Hz repetitive transcranial magnetic stimulation (rTMS) would improve psychomotor slowing in 82% of the participants. While this is encouraging, further evidence is needed to 1) replicate the clinical effect of 1 Hz rTMS on the SMA in schizophrenia, 2) to test against sham stimulation, facilitatory stimulation and no intervention, and 3) to test the effects of rTMS on the neural circuitry. Therefore, OCoPS includes more patients, more treatment arms, and more outcome variables than the first pilot trial. Here we will enroll 88 patients with schizophrenia spectrum disorders and severe psychomotor slowing according to a standard rating scale. Subjects will be randomized to four arms, three of which are double blinded. three weeks of daily rTMS over the SMA will be delivered. The first group receives inhibitory 1 Hz rTMS, the second group receives facilitatory intermittent theta burst stimulation (iTBS), and the third group receives sham stimulation with a placebo-coil. The fourth group will have no rTMS during the first three weeks, but will repeat the baseline measures after three weeks and then enter a treatment with 1Hz rTMS for three weeks. Outcome measures include the Salpetriere Retardation Rating Scale, observer ratings of motor behavior as well as measures of functioning. After the interventions, follow-up visits are planned at week 6 and week 24. Finally, at baseline and after the rTMS course, patients will undergo MRI scanning for structural and functional alterations of the cerebral motor system.