Researchers in Pisa, Italy recently published findings from a study of heroin addicts treated with either buprenorphine or methadone. The study was a follow-up to earlier studies by the same group; one that examined the personality characteristics of heroin addicts, and a second that measured the impact of agonist treatment on psychiatric symptomatology and the quality of life of heroin addicts.
The recent third study, published in the Annals of General Psychiatry, divided heroin addicts according to personality traits, and then examined whether these personality traits predicted success with one agonist treatment over another (i.e. methadone vs. buprenorphine).
‘Agonist treatment’ is used in the Italian studies to refer to maintenance with methadone or with buprenorphine—even though buprenorphine is technically a ‘partial agonist’ rather than an ‘agonist.’ Personality characteristics were defined using an instrument called the SCL-90 (Symptom CheckList-90).
In the first study, researchers found that the 1000 or so addicts could be divided into five subgroups, according to clusters of symptoms. One subgroup was characterized by depressive symptoms. The second was characterized by somatic symptoms, i.e. focus on physical symptoms and complaints. The third group was characterized by ‘interpersonal sensitivity’ and symptoms of psychosis—such as delusions. The fourth group had significant panic or anxiety symptoms, and the final group had symptoms related to violence toward self or others, including suicidality and self-mutilation.