Naltrexone is a medication prescribed to assist in recovery from Alcohol Use Disorder (AUD) and Opioid Use Disorder (OUD). As an opioid antagonist, it reduces cravings and helps prevent relapse. Like any medication, it has potential side effects that individuals should understand before treatment. This article explores the connection between naltrexone and mood alterations.
Naltrexone’s Effect on Brain Chemistry
Naltrexone functions by binding to and blocking opioid receptors within the brain. These receptors, specifically the mu-opioid receptors, are the same ones activated by substances like opioids and alcohol, producing feelings of pleasure. By occupying these sites without activating them, naltrexone prevents these substances from producing their rewarding effects, which helps to diminish the drive to use them.
The brain’s opioid receptors are also part of the body’s natural reward system, which is regulated by chemicals called endorphins. Endorphins are involved in mood regulation and the natural experience of pleasure. Because naltrexone blocks these receptors, it can also interfere with the normal activity of endorphins.
This interference can dampen the brain’s natural reward pathways, which are connected to the release of dopamine, a neurotransmitter associated with pleasure and motivation. For some individuals, this disruption of the reward cascade could contribute to a lowered mood or feelings of dysphoria.
Reported Mood-Related Side Effects
Depressed mood is a listed potential side effect of naltrexone, although it is considered uncommon. The range of reported symptoms is not limited to depression and can include anxiety, nervousness, and anhedonia, which is the inability to feel pleasure.
Data from clinical trials offer a mixed perspective. One trial examining naltrexone for opioid dependence found that participants did not experience a worsening of depressive symptoms. Some individuals who adhered to treatment even showed an improvement in depression over time. Other studies suggest some people might experience these mood changes, especially those with a pre-existing history of mental health conditions.
Another study found that while depression and anxiety were elevated at the start of treatment, these symptoms decreased within two months for those who remained in treatment, regardless of receiving naltrexone or a placebo. This suggests that improvements were likely related to the success of the treatment itself rather than a specific effect of the medication. The variability in these findings highlights that individual responses can differ.
Distinguishing Naltrexone Effects from Withdrawal Symptoms
A challenge for patients and clinicians is distinguishing naltrexone’s side effects from the symptoms of Post-Acute Withdrawal Syndrome (PAWS). PAWS describes symptoms that can persist for weeks or months after acute withdrawal has ended. This occurs because the brain requires a prolonged period to heal from the changes caused by substance use.
The symptoms of PAWS include depression, anxiety, irritability, fatigue, and anhedonia. These symptoms directly overlap with the mood-related side effects reported with naltrexone. This overlap makes it difficult to determine if a person’s low mood is a direct result of the medication or a part of the long-term recovery process.
PAWS symptoms often fluctuate, coming and going in waves that can be triggered by stress. For someone recovering from alcohol dependence, symptoms like depression can persist for years. Individuals recovering from opioid use can also experience these symptoms for months after stopping. Attributing mood changes solely to naltrexone without a thorough medical evaluation is premature.
Managing Mood Changes While on Naltrexone
Anyone experiencing mood changes while taking naltrexone should consult their prescribing healthcare provider. It is advised not to stop taking the medication abruptly, as this can complicate the recovery process. A physician can perform an assessment to explore the causes of the mood disturbance, including evaluating for underlying depression that may have been masked by substance use.
Based on this assessment, a doctor might consider several options. They may recommend adjusting the naltrexone dosage, as some side effects are dose-dependent. For instance, if fatigue is a concern, taking the medication at bedtime might help. A physician might also explore alternative medications or treatments for AUD or OUD.
A comprehensive treatment plan is important for managing both recovery and mood. This approach involves more than just medication. Therapies such as Cognitive Behavioral Therapy (CBT) can provide coping strategies for addiction and mood symptoms. Lifestyle habits, including regular exercise, proper nutrition, and peer support groups, also play a role in stabilizing mood and supporting recovery.