Naming for Psychotropic Drugs: Dilemma and Challenge

The current nomenclature of psychotropic drugs is primarily based on clinical indications. However, boundaries among various categories of psychotropic drugs are becoming less clear. For example, some “antipsychotics” are indicated not only for schizophrenia, but also for bipolar disorder and treatment-resistant depression. Similarly, “antidepressants” that have originally been developed to treat depression are now also used for the treatment of anxiety and a variety of other disorders. This discrepancy between terminologies and indications is a potential source of misunderstandings and disregards the intrinsic biological effects of these medications. In addition, frequently used terms such as “atypical antipsychotics” and “mood stabilizers” include various drugs into the same categories despite their different mechanisms of action and clinical profiles. New categories such as multi-acting receptor targeted antipsychotic (MARTA) and noradrenergic and specific serotonergic antidepressant (NaSSA) have sometimes been proposed but do not solve these problems Thus, the conventional classification of psychotropic drugs looks like a patchwork and is increasingly confusing and outdated.

To address these concerns, a taskforce for a new psychotropic nomenclature was established with representatives from 5 international organizations: the European College of Neuropsychopharmacology (ECNP), the Asian College of Neuropsychopharmacology (AsCNP), the American College of Neuropsychopharmacology (ACNP), the International College of Neuropsychopharmacology (CINP), and the International Union of Basic and Clinical Pharmacology (IUPHAR). This taskforce has developed a pharmacologically driven, rather than indication-based, nomenclature that embeds current scientific evidence in a systematic manner [1] [2]. The Neuroscience-based Nomenclature (NbN) provides a classification focusing on pharmacology, which synthesizes current knowledge and understanding of the targeted systems, neurotransmitters, molecules, and mechanisms of action. It also includes 4 additional dimensions: (1) approved indications, (2) efficacy and side effects, (3) “practical note,” which summarizes the clinical knowledge that has been prioritized by “filtering” through the task force’s “opinion sieve,” and (4) neurobiology. Moreover, to reflect conventional group terminology (e. g., antidepressants, antipsychotics, and mood stabilizers), a glossary has been developed. The newest version of the NbN is freely available on the project’s website (http://nbnomenclature.org/) and as an app (NbN) [3].

The developers of the NbN are fully cognizant of the fact that there is still a need for more evidence on mechanisms of action for psychotropic drugs. Indeed, many of the frequently used effective drugs in the field of psychiatry are not yet fully understood with respect to their mechanisms of action. On the other hand, the NbN is designed as a living classification, allowing new evidence to be easily added. Although further work is necessary to foster its development and acceptance by researchers, patients, and their caregivers, we consider this challenging project to be an important step in light of the limitations of the current nomenclature.

• References

• 1 Zohar J, Nutt DJ, Kupfer DJ et al. A proposal for an updated neuropsychopharmacological nomenclature. Eur Neuropsychopharmacol. 2014; 24: 1005-1014
• 2 Zohar J, Stahl S, Moller HJ et al. A review of the current nomenclature for psychotropic agents and an introduction to the Neuroscience-based Nomenclature. Eur Neuropsychopharmacol. 2015; 25: 2318-2325
• 3 Neuroscience-based Nomenclature. ECNP. http://nbnomenclature.org/