Nicotine effects on cognitive remediation training outcome in people with schizophrenia: A pilot study

Cognitive remediation training can alleviate cognitive impairment associated with schizophrenia, but the impact is limited by small effect sizes. The present study aimed at augmenting training effects by administering nicotine prior to training sessions. Twenty-five people with schizophrenia were enrolled in a 10-week, 5 days/week, computerized cognitive training regimen. Participants were randomized to two treatment groups: nicotine or placebo. Every Monday and Thursday, the nicotine group received a nicotine lozenge before the training, and the placebo group a placebo lozenge. Outcome measurements were conducted on a no-lozenge day in weeks 0, 4, 7, and 10, and at 4-week follow-up. The MATRICS Consensus Cognitive Battery composite score improved over time, but there was no group difference in this effect. A significant group difference emerged over time in the reasoning/problem solving sub-domain: the placebo group improved but not the nicotine group, suggesting that nicotine exposure negatively impacted training benefits on executive control processes. There were no effects on psychiatric symptoms. However, significant improvements were seen across groups on the Quality of Life Scale and the Cognitive Assessment Interview, measuring real-life functional outcome. In conclusion, the present study failed to find evidence that nicotine exposure during cognitive remediation training may potentiate training benefits.