Which medication is most helpful in the treatment of bipolar disorder?

• A. Chlorpromazine.
• B. Trifluoperazine.
• C. Chlordiazepoxide.
• D. Lithium carbonate.

Answer: (D)

Long-term mood stabilization is the key goal in bipolar disorder, and the medication with the strongest, most consistent evidence for both preventing manic and depressive episodes and reducing suicide risk is lithium carbonate. It acts as a mood stabilizer across episodes, helping to maintain a steady mood over time rather than just treating acute symptoms. Its efficacy in maintenance makes it the go-to choice for many patients, often used as first-line therapy for long-term management.

A few practical points help explain why lithium stands out: it requires careful monitoring because of its narrow therapeutic window, so serum levels are kept within a target range to avoid toxicity. Regular checks of kidney function and thyroid function are important since lithium can affect both systems. Staying well-hydrated and avoiding certain medications, like NSAIDs or some diuretics, helps prevent dangerous rises in lithium levels. Recognizing toxicity early—tremor, confusion, ataxia, GI symptoms—is crucial because management may require dose adjustment or discontinuation.

Other drugs listed serve different roles that aren’t focused on sustained mood stabilization. Chlorpromazine and trifluoperazine are antipsychotics useful for acute mania or psychotic features but are not designed for long-term maintenance. Chlordiazepoxide is a benzodiazepine with anxiolytic and sedative effects, helpful for agitation or short-term sleep but not for preventing future mood episodes in bipolar disorder.

So, lithium carbonate is the best choice for ongoing treatment aimed at stabilizing mood and reducing relapse risk.