Conclusion
neuropsychiatric disorders
COLD
In contrast with previous reports on the acute effects of SSRI administration, we did not find any significant effects on ‘cold’ cognitive measures after more chronic administration (mean 26 days). Using an innovative computational modelling approach, we did find significant effects specific to reinforcement learning; chronic escitalopram reduced reinforcement sensitivity compared to placebo. These novel findings provide strong evidence for a key role of serotonin in reinforcement learning. The results have important clinical implications as they may reflect the blunting effect often reported by patients with neuropsychiatric disorders receiving chronic SSRI treatment.