Maura is experiencing “shock” sensations in her head. Her mother says Maura stopped desvenlafaxine two weeks ago. The medication was prescribed by a pediatrician for social anxiety. Maura’s mother looked up information on desvenlafaxine and discovered it is categorized as an antidepressant. She doesn’t want Maura labeled “depressed” and requests alprazolam as an antianxiety medication.

Usual categories of medications do not match usage. For example, fluoxetine is used for obsessive-compulsive disorder (OCD) and guanfacine is prescribed off-label for sleep and tics. These categories are misleading for prescribers, patients, and families. Neuroscience-Based Nomenclature (NbN) classifies psychotropic medications based on mechanism of action and pharmacologic activity. In this article, we provide an overview of NbN’s potential to reduce the confusion and stigma surrounding psychotropic medications. 

NbN vs ATC

NbN was developed by the American College of Neuropsychopharmacology, the International Union of Basic and Clinical Pharmacology, and sister organizations worldwide as an alternative to the long-standing classification for psychotropic drugs, the Anatomical Therapeutic Chemical (ATC) system (Möller HJ et al, Eur Arch Psychiatry Clin Neurosci 2016;266(5):385–386).

Anatomical Therapeutic Chemical

ATC categorizes medications based on their FDA-approved uses for specific conditions and, in some instances, based on their general pharmacologic action (Caraci F et al, Br J Clin Pharmacol 2017;83(8):1614–1616). ATC categories for psychotropic medications include:

• Antidementia 
           
• Antidepressants
           
• Antiepileptics
           
• Antipsychotics
           
• Anxiolytics
           
• Hypnotics
           
• Mood stabilizers
           
• Psychostimulants 

Medications are often used for many FDA-approved and off-label purposes beyond their ATC category, and sometimes they have little efficacy even in their own category. This creates confusion for patients and clinicians, who might choose medications based only on their designated category. ATC categories may therefore influence and constrict our uses of medications. For example, consider the following: 

• Selective serotonin reuptake inhibitor (SSRI) antidepressants often work better for anxiety than for depression. 
• Serotonin and norepinephrine reuptake inhibitor (SNRI) antidepressants haven’t been shown to help depression in studies of children and teens (Walter HJ et al, J Am Acad Child Adolesc Psychiatry 2023;62(5):479–502)     
• Antianxiety medications (eg, benzodiazepines) interfere with learning anxiety management skills and are not recommended for kids and teens (Walter HJ et al, J Am Acad Child Adolesc Psychiatry 2020;59(10):1107–1124)    
• Antipsychotics have multiple uses beyond psychosis.

Neuroscience-Based Nomenclature   

NbN, by contrast, focuses on the chemical structure or action of medications. The system includes most psychotropics prescribed worldwide, encompassing over 100 medications. For example, methylphenidate, a psychostimulant in the ATC system, is a dopamine and norepinephrine reuptake inhibitor in NbN.

Maura’s previous prescriber tells you that they know that antidepressants work well for anxiety disorders. After seeing that fluoxetine did not work for Maura’s anxiety, he figured an SNRI antidepressant might be more effective. 

How might NbN improve clinical practice?

Here are some ways to use NbN in practice (Cortese S et al, J Am Acad Child Adolesc Psychiatry 2022;61(11):1317–1318). 

Adjust your pharmacotherapy approach

Patients often respond better to combinations of medications that have different pharmacologic properties. For example, guanfacine, a central alpha-­agonist, and lisdexamfetamine, a dopamine and norepinephrine reuptake inhibitor and releaser, can be used together for patients with ADHD. Prescribers who use NbN may be less likely to combine medications with the same pharmacologic ­properties. 

Reduce stigma

When patients see that their medication is defined by pharmacologic properties, rather than by their illness or the term “psychotropic,” it underscores the fact that their condition is not their fault and that their medication is intended to treat a physical problem and not a personal weakness (Caraci et al, 2017). For example, aripiprazole is a dopamine and serotonin receptor partial agonist in NbN. In the context of treating Tourette’s syndrome, this description for aripiprazole is less confusing than ­“antipsychotic.” 

Change how you discuss medications 

The action-based NbN classification helps patients and caregivers understand the intent behind a treatment. NbN helps us educate parents and patients who might not know about the efficacy of medications with different pharmacologic properties. This education can make it less likely, for instance, that a parent will request an antidepressant that has little likelihood of helping their child with ­depression. 

Explain off-label use

NbN also helps patients and families understand off-label use when they are prescribed a medication for a purpose beyond its FDA-approved indication. For instance, we might prescribe lurasidone off-label instead of FDA-approved aripiprazole for irritability in autism, largely to avoid metabolic side effects. You can use the moniker “dopamine-serotonin agents” to explain that both medications have similar activity, then describe their differing side effect ­profiles. 

Consider medication substitutions 

When there are medication shortages or formulary changes, NbN can help if you decide to make a medication substitution, perhaps trying an off-label medication with a similar mechanism of action (Uchida H, Psychiatry Clin Neurosci 2018;72(2):50–51). 

Improve patient safety 

Using NbN may help you avoid problematic medication combinations. Say a patient is depressed and taking fluoxetine, an antidepressant, but you are also considering buspirone, an anxiolytic, to treat their anxiety. NbN clarifies that both medications increase serotonin with a need to watch for hyperserotonergic symptoms. 

For more tips on how to start using NbN, see the box “Getting Started With NbN.”

You note to Maura’s parents that while SSRI antidepressants often work better for anxiety than for depression, SNRI antidepressants haven’t been shown to help depression or anxiety in studies of children and teens. You suggest to the prescriber a trial of another SSRI along with a course of therapy for social anxiety. Three months later, Maura’s mother contacts you to report that Maura is doing well on the new SSRI. 

A drawback of NbN  

Since we don’t know the actual mechanism of action for most psychotropic medications, complex language (eg, dopamine and norepinephrine reuptake inhibitor) may mislead patients and families. For example, it is not known why SSRIs can relieve ­depression.

CARLAT VERDICT

Avoid using ATC categories when you talk about psychotropic medications. Instead talk about specific medications—for diagrammatic algorithms, see the new edition of our Child Medication Fact Book (Feder J et al. Child Medication Fact Book for Psychiatric Practice. 2nd ed. Newburyport, MA: Carlat Publishing; 2023)—and remember that NbN categories do not imply a deeper understanding of pathophysiology.