From the Research
N-acetylcysteine (NAC) is indeed used in psychiatry as an adjunctive treatment for several mental health conditions, with the most recent and highest quality evidence supporting its use in depression, particularly bipolar disorder, as shown in the 2024 study 1.
Key Points
- NAC is primarily utilized for obsessive-compulsive disorder (OCD), trichotillomania (hair-pulling disorder), excoriation (skin-picking) disorder, and substance use disorders, particularly for reducing cravings in addiction.
- The typical dosage ranges from 600-2400 mg daily, often divided into two doses, as seen in the 2022 study 2.
- NAC works by regulating glutamate, an important neurotransmitter in the brain, and through its antioxidant properties which may reduce oxidative stress and inflammation that contribute to psychiatric symptoms, as discussed in the 2021 study 3.
- NAC is generally well-tolerated with mild side effects like nausea, vomiting, or diarrhea, as reported in the 2018 study 4.
- While NAC is available over-the-counter as a supplement, patients should consult with a healthcare provider before starting it, especially if they're taking other medications, as it may interact with certain drugs like nitroglycerin, as noted in the 2017 study 5.
Mechanism of Action
- NAC helps restore glutathione levels, which are often depleted in various psychiatric conditions, as mentioned in the 2022 study 2.
- It also modulates glutamatergic, dopaminergic, neurotropic, and inflammatory pathways, as discussed in the 2017 study 5.
Clinical Evidence
- A 2024 meta-analysis 1 found that adjunctive NAC can ameliorate depressive symptoms in patients with psychiatric problems, particularly bipolar disorder.
- The 2022 study 2 noted that NAC has the most evidence of having a beneficial effect as an adjuvant agent in the negative symptoms of schizophrenia, severe autism, depression, and obsessive-compulsive and related disorders.
- The 2018 study 4 found that adjunctive NAC significantly improved total psychopathology in schizophrenia, but had no significant effect on depressive and manic symptoms in bipolar disorder.