The invention concerns methods of treating suicidal ideation or behavior in a subject in need thereof, comprising decreasing endogenous nicotinic acetylcholine receptor (nAChR) activity in the subject therapeutic packages for treating suicidal ideation or behavior and methods for determining the efficacy of a treatment for suicidal ideation or behavior. In some embodiments, the treatment methods comprise administering to the subject an effective amount of an inhibitor of a nAChR, such as a lithium compound, mecamylamine, clozapine, or asenapine.
