Differential Effects Of Cannabis Versus Tobacco On Theta-Gamma Coupling In Schizophrenia

Co-morbid cannabis dependence in schizophrenia significantly exacerbates positive and negative symptoms; however effects on cognition are unclear. Tobacco, which is often co-administered with cannabis, may have beneficial effects on cognition. Impaired theta-gamma coupling in dorsolateral prefrontal cortex (DLPFC) has been hypothesized to underlie pervasive working memory deficits in this disorder. This study determined effects of cannabis and tobacco on coupling during working memory performance among 4 groups: cannabis+tobacco versus tobacco smoking patients with schizophrenia, compared to non-psychiatric controls.