Substance-dependent patients(SDP) have more personality disorders(PD) than general population; and they present more frequent and severe levels of depression and anxiety.

To study cluster C personality disorders in SDP.

We included a clinical sample of 822(621 males) SDP according to the DSM-IV-TR criteria seeking treatment in the Outpatient Drug Clinic Vall d’Hebron in Barcelona, Spain.

The assessment process consisted of three interview sessions conducted by trained psychiatrists and psychologists using SCID I and II, BDI, STAI-R/S. Exclusion criteria were:intoxication at baseline examination, severe somatic disease at baseline examination and low language proficiency.

39.2% of the sample presented at least one PD and 9.55% presented a cluster C PD. Of them the found prevalence were Avoidant(44.9%), Dependt(11.5%), Obssessive-compulsive(37.2%), comorbidity (6.4%). The addiction prevalences that Cluster C PD patients show were: dependent of alcohol 9.4%, benzodiazepines 18.5%, opioids 6.1%, cocaine 9.7 and cannabis 12.3%.

70.5% of the PD cluster C group were men, however differences according to the cluster C PD were found, being higher the proportion of men in Obsessive-compulsive PD (85.7%) and fewer in Dependent PD patients (33.7%)(χ2 =12.19, p = .007).

Cluster C PD patients presented more depressive symptoms and showed higher scores in anxiety-trait than patient with Cluster A or B PD, being this difference statistically significant.

There is a high rate of cluster C personality disorders among addicted patients. Higher levels of anxiety depression are detected in these patients. Clinicians should be check systematically this symptoms and traits in addicted patients.