The term "mood stabilizer" does not describe a mechanism, but rather an effect. More precise terminology is used to classify these agents.
Drugs commonly classed as mood stabilizers include:
Lithium – Lithium is the "classic" mood stabilizer, the first to be approved by the US FDA, and still popular in treatment. Therapeutic drug monitoring is required to ensure lithium levels remain in the therapeutic range: 0.6 or 0.8-1.2 mEq/L (or millimolar). Signs and symptoms of toxicity include nausea, vomiting, diarrhea, and ataxia. The most common side effects are lethargy and weight gain. The less common side-effects of using lithium are blurred vision, slight tremble in the hands, and a feeling of being mildly ill. In general, these side-effects occur in the first few weeks after commencing lithium treatment. These symptoms can often be improved by lowering the dose.