Chronic depersonalization following illicit drug use: a controlled analysis of 40 cases.

AIMS To examine demographic and clinical features of a group of patients reporting chronic depersonalization (DP) following illicit drug use, and to assess whether depersonalization arising in these circumstances constitutes a distinct clinical syndrome. DESIGN Case-control comparison using self-reports, standardized questionnaires and clinical assessments in a specialized clinic. SETTING A tertiary referral depersonalization clinic and research unit affiliated to a psychiatric hospital and research centre. PARTICIPANTS A total of 164 individuals with chronic DP symptoms who had been in contact with the clinic. Forty of these individuals related the onset of symptoms to an episode of illicit drug use. MEASUREMENTS A wide range of demographic and clinical variables measured using questionnaires and standardized rating scales. FINDINGS The drug-induced DP group were significantly younger and had a preponderance of males compared to the non-drug group. Certain clinical and phenomenological differences were found between these groups, but in general the groups are strikingly similar. This is reinforced by the fact that when the drug-induced group was compared with an age and sex-matched subset of the non-drug group, differences between groups largely disappeared. CONCLUSIONS Drug-induced DP does not appear to represent a distinct clinical syndrome. The neurocognitive mechanisms of the genesis and maintenance of DP are likely to be similar across clinical groups, regardless of precipitants.