This study aims to understand the patterns that occur in a large sample of addicted patients and to characterize each of them according to psychological and psychopathological manifestations. On a sample of 1,406 subjects who initiated treatment for addictive behaviours in a drug addiction care centre, a cluster analysis of their responses to the Millon-II Multi-Axial Clinical Inventory (MCMI-II) was carried out. Each conglomerate obtained was matched with the mean obtained in other tests that explored psychological and psychopathological variables. It was found that 32.5% of the sample presented severe personality patterns, which would correspond to the diagnoses of schizotypal, borderline, antisocial and avoidant disorders, while 42.2% did not present any problematic patterns. Women were more likely than men to have severe patterns, and the latter were more likely to have non-problematic patterns. It is concluded that the diagnosis can be reduced to four clinical presentations, allowing for the design of a menu of psychological and neuropsychological interventions, which would have repercussions on the improvement of patients and the efficiency of the interventions.