Order of age at onset for substance use, substance use disorder, conduct disorder and psychiatric illness

Abstract

This study aimed to assess the number of patients who reported earlier age at onset for psychiatric illness versus those with an earlier age at onset for substance use. Subjects were 194 patients from substance use disorder (SUD) treatment services in the Municipality of Fredericia who accepted an offer of psychological assessment. Patients were administered the Mini International Neuropsychiatric Interview (MINI), and when diagnoses were indicated, queried about the age at onset for each disorder. Additionally, subjects were administered the WAIS-III vocabulary scale, the Structured Assessment of Personality – Abbreviated Scale (SAPAS), completed the MCMI-III, the Beck Anxiety Inventory (BAI), and were rated with the Montgomery Åsberg Depression Rating Scale. Age at onset was lowest for conduct disorder/antisocial behaviour, followed by tasting alcohol, trying drugs, post-traumatic stress disorder and social phobia. Of patients reporting an age at onset for SUD and conduct disorder, 84% reported that age at onset was earliest for conduct disorder. Of patients reporting an age at onset for both any non-substance related axis I disorder and any substance related disorder, age at onset was earliest for non-substance related disorder in 72%. Patients reporting that their axis I disorder predated their SUD reported more severe problems currently on the BAI and the SAPAS. Patients reporting that their conduct disorder/antisocial personality disorder criteria predated their SUD reported more aggressive-sadistic personality traits than patients reporting that SUD predated conduct disorder/antisocial personality, but did not differ in terms of antisocial personality disorder traits. The findings are discussed in terms of their clinical implications.

Keywords:

• age of onset
• substance use disorders
• conduct disorder
• anxiety
• depression
• psychosis