Iproniazid phosphate is primarily used in the field of psychiatry and neurology as a monoamine oxidase inhibitor (MAOI). It is employed in the treatment of depression, particularly in cases where other antidepressants have proven ineffective. By inhibiting the activity of monoamine oxidase, it increases the levels of neurotransmitters like serotonin, norepinephrine, and dopamine in the brain, which helps alleviate depressive symptoms. Additionally, it has been explored for its potential in managing certain neurological disorders, though its use is limited due to the risk of serious side effects and the availability of safer alternatives. Its application requires careful monitoring to avoid adverse interactions with other medications or dietary components.