Effects of short-term, high-frequency repetitive transcranial magnetic stimulation to bilateral dorsolateral prefrontal cortex on smoking behavior and cognition in patients with schizophrenia and non-psychiatric controls.

BACKGROUND

High rates of tobacco smoking and smoking cessation failure in schizophrenia may be related to prefrontal cortical dysfunction. Novel treatment options for tobacco use disorder are needed given the limited efficacy of current pharmacotherapies. Preliminary evidence suggests high-frequency repetitive transcranial magnetic stimulation (rTMS) to bilateral dorsolateral prefrontal cortex (DLPFC) may suppress tobacco craving in smokers with schizophrenia. The goal of this study was to determine effects of rTMS for tobacco craving and cognition using a short-term (3-day) human laboratory paradigm.

METHODS

Bilateral active (20Hz) versus sham rTMS stimulation was administered in a counterbalanced, double-blind, cross-over design to thirteen smokers with schizophrenia and n=14 non-psychiatric smoking controls. Participants were studied at baseline (smoking satiated), after 16h of smoking abstinence, and after smoking reinstatement. Primary outcome measures included tobacco craving, withdrawal and cognition.

RESULTS

Overnight abstinence produced a significant increase in tobacco craving and withdrawal, and impaired verbal memory and visuospatial working memory in both diagnostic groups; these effects were reversed with smoking reinstatement. However, active rTMS did not modify this pattern of results. Moreover, active versus sham rTMS had no significant effects on cognitive outcomes, and was not associated with significant adverse events.

CONCLUSIONS

Our preliminary findings suggest that short-term rTMS administration may not be sufficient enough to modify cognition, craving, and withdrawal outcomes in smokers with schizophrenia (NCT00736710). Longer-term, controlled treatment studies examining effects of rTMS on smoking behaviors and cognition in schizophrenia are warranted.