From symptoms to neurobiology: pathological gambling in the light of the new classification in DSM-5.

Pathological gambling (PG), as defined until recently in the DSM-IV, shares many clinical characteristics with substance use disorders (SUDs), such as craving and loss of control. Moreover, an increasing body of literature also revealed neurobiological similarities between PG and substance-related addictions. Further, specific treatments for SUD are also effective in pathological gamblers. These observations resulted in a recent change in the diagnostic classification of PG in DSM-5: maladaptive gambling behavior is now subsumed as 'gambling disorder' (GD) under the category 'substance-related and addictive disorders'. On the basis of similarities in clinical characteristics between GD and SUDs, this article proposes 3 main clusters of diagnostic criteria: 'loss of control', 'craving/withdrawal' and 'neglect of other areas in life'. These symptom clusters can then be related to the experimental paradigms commonly used in the neuroscience of addiction, including neuropsychological, neurophysiological and neuroimaging studies. In this paper, we present the neurobiological evidence for PG by focusing on key functional magnetic resonance imaging studies related to these 3 symptom clusters. It is concluded that these symptom clusters provide a useful framework for systematic comparisons of new evidence in GD and SUDs in the future.