Introduction: The somatic marker hypothesis proposes that somatic signals guide the decision making processes in an adaptive sense for the organism. The processing of these somatic signals is linked to the ventromedial prefrontal cortex activity. The influence of somatic markers on decision making processes has been studied by means of the 'gambling task' (GT). Several studies using the GT in substance abusers have showed the existence of decision making impairments in these patients.
Aims: To examine the performance in the GT of a Spanish sample of substance abusers; and to study the influence of clinically relevant variables: type of substance, years of abuse and abstinence period on GT performance.
Patients and methods: 106 substance abusers patients during the dishabituation phase participated in the study. We administered a computerized version of the GT in a single individual session. We used descriptive analyses to study the patients' performance in the GT. Next we carried out multiple regression analyses to study the influence of the clinical variables on the GT performance.
Results: A 76.4% of the sample patients showed impairments in the decision making processes measured by the GT. None of the clinical variables significantly predicted performance in the task.
Conclusions: These results suggest the existence of decision making impairments in substance abusers that may be related to pre morbid alterations, or to a neurotoxic effect of drugs of abuse on the activity of the ventromedial prefrontal cortex.