Finding the safest and most effective support for a child’s mental health can be challenging. While medications are frequently prescribed, their benefits are often modest and come with unwanted side effects. This has led researchers to explore other options, including a nutritional supplement: N-acetylcysteine (NAC).

N-acetylcysteine has been explored for treating a number of different mental health conditions in adults, including obsessive-compulsive disorder. NAC is a form of the amino acid cysteine that bolsters the body’s antioxidant defense systems. It also works as a brake, to slow down brain overactivity by regulating key neurotransmitters, including glutamate.

These benefits appear to be broadly supportive for mental health. While many medications, including antidepressants, have only marginal benefits for children, research on NAC suggests that it may have significant potential. While the research is still in the early stages, the safety of NAC could still make it a choice worth considering in a number of different mental health conditions in kids.

NAC in Pediatric Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) can be incredibly disruptive for children and families, and treatment often requires patience and persistence. Studies on medications for OCD show some efficacy but typically with modest results (McGuire 2015). Even with medications, many children still have significant symptoms that can cause disruptive obsessions and compulsions, making life more challenging.

As a treatment for children with OCD, NAC shows promise:

• A study from 2017 found that NAC, when added to medication, almost halved OCD symptoms, where placebo provided no significant changes (Ghanizadeh 2017)
• A small pilot study also found significant improvements in OCD symptoms in children treated with both standard methods combined with NAC as compared to no additional benefits from placebo (Li 2020)

In both studies, NAC was well tolerated without serious side effects. Target dosing for OCD was between 2400 and  2700 mg per day in divided doses. In general, NAC is often started at a lower dose and increased weekly up to the target dosing range.

NAC in Bipolar Mania

Bipolar disorder is another condition that can easily disrupt lives and families, often having life-long consequences. For patients with bipolar disorder, medications offer some relief, but often with the risk of serious side effects, including weight gain, heart disease, kidney disease and other serious health concerns.

NAC is being explored as a safer option.

An initial pilot study in children and adolescents found significant improvements in both mania and depression symptoms with NAC (Wozniak 2022). Dosing was 1800 mg for children and 2700 mg for adolescents, titrated up to the target dose over two or three weeks. In the study, 54% of children had a reduction in manic symptoms greater than 30%. Depressive symptoms were also improved with 62% responding with a greater than 30% reduction in symptoms. While the results are encouraging, further clinical trials are needed to confirm the benefits.

NAC for Cannabis Use Disorder

With interest in cannabis for medical purposes at an all-time high, combined with expanding state-level access, cannabis use and abuse is increasing in adolescents, raising concerns for parents and families (O’Grady 2024).

Of interest, NAC may have potential for the treatment of cannabis use disorders. A study in 116 adolescents or young adults with cannabis dependence that wanted to decrease use found benefits. During the study, participants on NAC were more successful in decreasing cannabis as compared to those on placebo (Gray 2012). Over the course of the study, the rate of negative urine tests for cannabis was 41% with 1200 mg of NAC twice daily as compared to 27% without.

Autism and Irritability

For many children on the autism spectrum and their families, managing intense irritability—which can show up as aggression, frustration, or outbursts—can be one of the most significant daily hurdles.

As a support for individuals on the autistic spectrum, NAC has been studied for potential benefits:

• The first clinical trial in 2012, while small, still found significant improvements in irritability as compared to placebo (Hardan 2012).
• A similar trial that combined medication with NAC or placebo also found benefits for children with autism (Ghanizadeh 2013). NAC led to a decrease of 27% in irritability as compared to just a 10% reduction with placebo.
• One other trial had similar findings, showing reductions in irritability and hyperactivity by ten weeks with NAC (Nikoo 2015).

However, not all studies have found benefits (Wink 2016). Unfortunately, the largest trial to date used the lowest dose of NAC, just 500 mg per day, and did not find significant improvements (Dean 2017). The authors themselves acknowledge that their findings could have been negatively influenced by the use of such a low dose.

Overall, reviews of the research still suggest significant improvements in irritability with NAC supplementation for individuals with autism. An analysis from 2021 concluded that NAC likely decreases hyperactivity, irritability and enhances social awareness in individuals with autism (Lee 2021). In addition, NAC is safe and well tolerated with effective doses likely starting around 600 mg up to at least 2700 mg.

Conclusion

NAC has significant potential for helping with a number of different mental health conditions. For children struggling with symptoms of OCD, bipolar disorder, cannabis use disorder, autism and irritability, NAC may provide benefits. The most common side effects are gastrointestinal symptoms, although NAC is typically well tolerated. For anyone considering NAC for their child, make sure to discuss its use with a qualified health-care professional to ensure it is an appropriate treatment.

References

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Ghanizadeh A, Moghimi-Sarani E. A randomized double blind placebo controlled clinical trial of N-Acetylcysteine added to risperidone for treating autistic disorders. BMC Psychiatry. 2013;13:196. Published 2013 Jul 25. doi:10.1186/1471-244X-13-196

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