What is the most appropriate management for a patient with narcissistic personality disorder exhibiting mood swings?

The most appropriate management for a patient with narcissistic personality disorder exhibiting mood swings is lithium. This medication is a mood stabilizer commonly used in managing mood disorders, particularly in patients who exhibit significant mood instability or affective lability. In the context of narcissistic personality disorder, individuals may experience intense mood swings that can benefit from the stabilizing effects of lithium.

Lithium acts by modulating neurotransmitter levels and has a proven track record in stabilizing mood for those who might also present with bipolar-like symptoms or significant emotional dysregulation.

While other options exist, they may not address the mood swings as effectively in this specific context. Fluoxetine, an SSRI, would primarily treat depressive symptoms but is not a first-line option for mood stabilization in this scenario. Clonazepam can help with anxiety and agitation but lacks the targeted effect on mood stabilization that is essential here. Divalproex sodium is also a mood stabilizer but is more often indicated for bipolar disorder or seizure management rather than specifically for personality disorders with mood swings. Therefore, lithium's established role in stabilizing mood makes it the most suitable choice for this patient.