Sexual Dysfunction in Men Receiving Methadone Maintenance Treatment: Clinical History and Psychobiological Correlates

A variety of studies evidenced a relationship between drug use disorders and sexual dysfunction. In particular, heroin and opioid agonist medications to treat heroin dependence have been found to be associated with erectile dysfunction and reduced libido. Controversial findings also indicate the possibility of factors other than the pharmacological effects of opioid drugs concurring to sexual dysfunction. With the present study, we investigated the link between sexual dysfunction and long-term exposure to opioid receptor stimulation (heroin dependence, methadone maintenance treatment, methadone dosage), the potentially related hormonal changes reflecting hypothalamus-pituitary-gonadal axis function and prolactin (PRL) pituitary release, the role of adverse childhood experiences in the clinical history and the concomitant symptoms of comorbid mental health disorders in contributing to sexual problems. Forty male patients participating in a long-term methadone treatment program were included in the present study and compared with 40 healthy control subjects who never used drugs nor abused alcohol. All patients and controls were submitted to the Arizona Sexual Experiences Scale (ASEX), Child Experiences of Care and Abuse-Questionnaire (CECA-Q) and the Symptom Check List-90 Scale. A blood sample for testosterone and PRL assays was collected. Methadone dosages were recorded among heroin-dependent patients on maintenance treatment. Methadone patients scored significantly higher than controls on the 5-item rating ASEX scale, on CECA-Q and on Symptoms Check List 90 (SCL 90) scale. Testosterone plasma levels were significantly lower and PRL levels significantly higher in methadone patients with respect to the healthy control group. ASEX scores reflecting sexual dysfunction were directly and significantly correlated with CECA-Q neglect scores and SCL 90 psychiatric symptoms total score. The linear regression model, when applied only to addicted patients, showed that methadone dosages were not significantly correlated with sexual dysfunction scores except for 'erectile dysfunction', for which an inverse association was evidenced. Testosterone values showed a significant inverse correlation with ASEX sexual dysfunction scores, CECA-Q neglect scores and psychiatric symptom at SCL 90 among methadone patients. PRL levels were directly and significantly correlated with sexual dysfunction scores, psychiatric symptoms at SCL 90 and CECA-Q neglect scores. Both testosterone and PRL did not correlate with methadone dosages. The present findings appear to support the view of childhood adversities and comorbid psychiatric symptoms contributing to sexual dysfunction and related hormonal changes among methadone patients, challenging the assumption that attributes sexual problems entirely to the direct pharmacological effects of opioid agonist medications.