Purpose of review: Problems relating to impulsivity, attention, and working memory occur in many neuropsychiatric disorders and represent important targets for pharmacological intervention. The purpose of this article is to review recent neuropharmacological manipulation studies in humans relating to these domains.
Recent findings: Serotonin manipulations in healthy volunteers did not affect response inhibition, a cognitive function implicated in impulsive symptoms of attention deficit hyperactivity disorder, trichotillomania, and substance abuse. Serotonin manipulations did affect performance on cognitive tests involving emotionally salient rewards and feedback, suggesting involvement of this neurochemical in affective aspects of impulsivity. Attentional deficits in attention deficit hyperactivity disorder and visuospatial neglect were ameliorated by noradrenergic drugs. Noradrenergic beta-blockade suppressed the encoding of emotionally arousing unpleasant stimuli and reduced amygdala activation in healthy volunteers, with potential implications for posttraumatic stress disorder. Dopaminergic manipulations affected aspects of working memory in healthy volunteers and in patients with Parkinson's disease, with evidence for bidirectional effects depending on baseline performance.
Summary: Recent findings raise exciting prospects for modulating impulsivity, attention, and working memory in a variety of neuropsychiatric disorders. Future studies should use computerized cognitive assessment, measures of functional genetic polymorphisms, and neuroimaging techniques, in order to further elucidate the neurochemical substrates of cognition and optimize treatment approaches.