Mental health outcomes following naltrexone implant treatment for heroin-dependence

BackgroundOral naltrexone is an approved treatment for opioid dependence. However, the impact of sustained release naltrexone on the mental health of treated opioid users has not been studied.AimsTo assess if naltrexone via implant treatment was associated with any change in (i) risk, (ii) rate, and (iii) duration for hospital morbidity related to several categories of mental disorders among treated heroin users.MethodA cohort of 359 heroin users treated with sustained release naltrexone via implants in Western Australia was retrospectively followed up for mental health related outcomes via a health record linkage system over an average period of 1.78 years post-treatment.ResultsIndividual patient's risk for hospital mental diagnoses was not altered after naltrexone implant. On a population cohort level, hospital admission rates related to all mental health problems, except mood disorders, declined significantly post-treatment; however, length of hospital stay did not improve. Overall, young, female patients or those with pre-existing mental illness were more likely than other patients to require hospital care for mental health issues following treatment. Longer period of heroin use was associated with poorer mood outcomes.ConclusionsNaltrexone implants were not associated with an increased risk for hospitalisation due to mental illness, and in most cases, were associated with a decrease in mental related hospital admission rate.