The neuropharmacology of impulsive behaviour

Impulsivity is a heterogenous phenomenon encompassing several behavioural phenomena that can be dissociated neuroanatomically as well as pharmacologically. Impulsivity is pathological in several psychiatric disorders including attention-deficit/ hyperactivity disorder (ADHD), drug addiction and personality disorders. Pharmacological agents alleviating impulsivity therefore might substantially aid the treatment of these disorders. The availability of preclinical models that measure various forms of impulsivity has greatly increased our understanding of its neuropharmacological substrates. Historically, deficits in central serotonin neurotransmission are thought to underlie impulsivity. Accumulating evidence also points towards an important role of brain dopamine and noradrenaline systems in impulsive behaviour, consistent with the therapeutic efficacy of amphetamine, methylphenidate and atomoxetine in ADHD. However, recent findings also implicate glutamate and cannabinoid neurotransmission in impulsivity. In this review, we will discuss some of the recent developments in the neuropharmacological manipulation of impulsive behaviour.