The promise and pitfalls of intranasally administering psychopharmacological agents for the treatment of psychiatric disorders.

Accumulating research demonstrates the potential of intranasal delivery of psychopharmacological agents to treat a range of psychiatric disorders and symptoms. It is believed that intranasal administration offers both direct and indirect pathways to deliver psychopharmacological agents to the central nervous system. This administration route provides a unique opportunity to repurpose both old drugs for new uses and improve currently approved drugs that are indicated for other administration routes. Despite this promise, however, the physiology of intranasal delivery and related assumptions behind the bypassing of the blood brain barrier is seldom considered in detail in clinical trials and translational research. In this review, we describe the current state of the art in intranasal psychopharmacological agent delivery research and current challenges using this administration route, and discuss important aspects of nose-to-brain delivery that may improve the efficacy of these new therapies in future research. We also highlight current gaps in the literature and suggest how research can directly examine the assumptions of nose-to-brain delivery of psychopharmacological agents in humans.