Naltrexone for Self-Harm in Adults
Low-dose naltrexone (1-5 mg daily) is not appropriate as adjunct treatment for self-harm in adults, as there is no guideline support, no FDA approval for this indication, and the limited research evidence shows inconsistent results primarily in developmentally disabled populations rather than typical adult psychiatric patients.
Evidence Quality and Applicability
The available evidence for naltrexone in self-injurious behavior comes exclusively from small studies in patients with developmental disabilities, not the general adult psychiatric population you are asking about. The American Academy of Family Physicians recognizes naltrexone only for opioid dependence and alcohol use disorder, with no mention of self-harm or self-injurious behavior 1. The FDA has approved naltrexone exclusively for opioid dependence and alcohol use disorder, not for any behavioral condition like self-harm 2.
Research Evidence Limitations
The research base consists of:
A 1996 open-label trial of 7 female psychiatric patients showing cessation of self-injurious behavior in 6 of 7 patients on 50 mg/day naltrexone, but this was uncontrolled and had only 10.7 weeks mean follow-up 3
A 2004 meta-analysis found that 80% of 86 subjects with developmental disabilities showed improvement, but only 47% achieved ≥50% reduction in self-injury, and these were predominantly patients with mental retardation and autism—not typical adult psychiatric patients 4
Contradictory findings exist: a 1987 double-blind study of two profoundly mentally retarded adults found "no measurable effects" on self-injurious behavior over 12-18 weeks 5
Critical Safety Concerns for This Population
Naltrexone carries significant risks that are particularly problematic in patients with self-harm:
Patients who discontinue naltrexone have decreased opioid tolerance and increased risk of overdose and death if they use opioids 1, 6
Naltrexone blocks all opioid receptors, meaning patients cannot receive effective pain relief from opioid analgesics for injuries, surgical procedures, or medical emergencies 1, 6
Oral naltrexone must be held 2-3 days before any procedure requiring opioids; extended-release formulations require 24-30 days 7, 1
Hepatotoxicity requires baseline liver function tests and monitoring every 3-6 months 1, 2
Dosing Mismatch
You asked about "low-dose" naltrexone (typically 1-5 mg daily), but all evidence for self-injurious behavior used standard therapeutic doses of 50 mg daily 3, 8. Low-dose naltrexone at 1-5 mg daily is used off-label for various conditions but has no evidence base for self-harm 1. The standard FDA-approved dose for opioid/alcohol dependence is 50 mg daily, which achieves complete mu-opioid receptor blockade 1.
Alternative Approach
Rather than naltrexone, focus on:
- Evidence-based treatments for the underlying psychiatric condition driving self-harm (depression, borderline personality disorder, trauma)
- Dialectical behavior therapy and other psychotherapeutic interventions proven for self-harm
- Appropriate psychotropic medications targeting the primary psychiatric diagnosis
Common Pitfalls to Avoid
Do not extrapolate research from developmentally disabled populations to general adult psychiatric patients—these are fundamentally different clinical contexts 3, 9, 8, 4
Do not prescribe naltrexone without ensuring the patient is completely opioid-free, as this will precipitate severe withdrawal 1, 6
Do not use naltrexone in patients who may require opioid analgesia for medical conditions, injuries, or procedures 1, 6
Do not confuse the mechanism of naltrexone in addiction (blocking reward pathways) with a presumed mechanism in self-harm—the endogenous opioid hypothesis for self-harm remains unproven in typical adult psychiatric populations 3