Updating the role of dopamine in human motivation and apathy

Apathy is a paradigmatic disorder of motivation, and is encountered across a breadth of neurological and psychiatric disease. Importantly, apathy is not a unitary symptom - rather, it is a syndrome comprising a constellation of impairments across multiple domains of behaviour. Recent work has focused on characterising the distinct neurophysiological mechanisms that give rise to clinical apathy. Although dopamine has long been known to have a central role in complex behaviour, current data indicate that its roles in the learning and valuation of effort and reward may underlie distinct subtypes of motivational impairment. A focus of future work will be to map the involvement of dopamine in motivated decision-making to separate domains of apathy. This will facilitate not only a greater understanding of the neurobiology of motivational disorders, but also the development of targeted, neurobiologically based treatments.