Can narcissism lead to suicide?

Yes: One study showed patients suffering from narcissistic personality disorder made suicide attempts which were less impulsive but more lethal.

Sometimes: Narcicssism as a trait is relatively common, though it has to be severe and dysfunctional before it raises to a level of being a disorder. Suicide is statistically rare, so clearly there are many many narcissistic individuals who do not become suicidal. While the "self-love" of narcissism usually tends to inhibit self-harm, the classic high-risk time is "narcisstic injury" - a big blow to ego.

Narcissism: Narcissistic rage can result from narcissistic injury, which is a threat to self-esteem/self-worth. When this is turned inwards, and judgment is impaired, suicidal tendencies can occur.

Narcissism: Personality disorders in general are at higher risk for suicide. Narcissists eventually drive everyone around themselves away through the toxicity of their very presence. and cannot see or understand their part in their own misery, which leads eventually to depression and possibly suicide. The core of it is they cannot face their own abysmal self-esteem or the reasons for it.