Early and late onset group of substance misusers : differences in primary and secondary psychiatric disorders (2004)

Aim: To identify clinical differences between early onset (EO; at age <18 years) and late onset (LO; at age 18 years or older) groups of patients with substance use disorders (SUD). Sample: A naturalistic, consecutive sample of DSM-IV alcohol-dependent (n=156) and polysubstance-dependent patients (n=131) from three outpatient and six inpatient public programmes in two neighbouring counties in Norway. Methods: Primary axis I disorders (occurring at least 1 year before any SUD) and secondary axis I disorders (occurring at least 1 year after any SUD) were assessed with the Composite International Diagnostic Interview (CIDI); axis II disorders were assessed with Millon Clinical Multiaxial Inventory (MCMI)-II. Results: In the EO group, significantly more clients had primary anxiety disorders, (especially social phobia and post-traumatic stress disorder (PTSD)) and antisocial, borderline and passive-aggressive personality disorders (PDs), and fewer had dependent and compulsive PDs. EO strongly predicted polysubstance misusers (vs. pure alcoholism) and had more frequent secondary PTSD. Results were generally identical when a cut-off point of 25 years was used. The average EO patient's SUD manifested 6 years before psychiatric treatment, whereas the LO patients had been in psychiatric treatment for 2 years before the SUD. Conclusion: EO/LO allowed the delineation of two clinical subgroups and provided information about possible prevention strategies, early interventions and treatment.