Bipolar Disorder Treatment Medications How Reuptake Inhibitor Drugs Work By Marcia Purse Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing. Learn about our editorial process Marcia Purse Reviewed by Reviewed by Amy Morin, LCSW on July 01, 2019 facebook twitter instagram Amy Morin, LCSW, is the Editor-in-Chief of Verywell Mind. She's also a psychotherapist, international bestselling author and host of the Mentally Strong People podcast. Learn about our Review Board Amy Morin, LCSW Updated on February 06, 2021 Print Joe Raedle/Getty Images Table of Contents View All Table of Contents What Reuptake Inhibitors Do Types of Reuptake Inhibitors Confused about SSRIs vs SNRIs and other similar acronyms? ‘RI’ stands for ‘reuptake inhibitor.’ Reuptake inhibitors are a type of drug used to treat depression, anxiety, and other psychiatric conditions. They work by increasing the concentration of certain brain chemicals, known as neurotransmitters, to alter mood. There many types of reuptake inhibitors, including: Selective serotonin reuptake inhibitors (SSRIs)Serotonin-norepinephrine reuptake inhibitors (SNRIs)Norepinephrine reuptake inhibitors (NRIs)Norepinephrine-dopamine reuptake inhibitors (NDRIs)Serotonin-norepinephrine-dopamine reuptake inhibitors (SNDRIs) While the drugs all have similar mechanisms of action, they differ in the types of neurotransmitter they target. To understand how reuptake inhibitors work, you need to get a better sense of what neurotransmitters actually do. Neurotransmitters and Mood A neurotransmitter is a chemical messenger that carries, boosts, and balances signals between nerve cells (neurons) and target cells throughout the body. Billions of neurotransmitter molecules work to keep our brains functioning, managing everything from our breathing to a variety of psychological functions such as fear, mood, pleasure, and joy. For the purpose of treating mood disorders, three specific neurotransmitters are targeted, each of which is associated with mood elevation: Dopamine plays a central role in reward-motivated behavior by stimulating the emotional desire for a "reward" in the form of pleasure.Norepinephrine works by mobilizing the brain and body for action, increasing alertness, focus, and the retrieval of memory.Serotonin plays a regulatory role in moods, social behavior, appetite, sleep, memory, sexual desire, and sexual function. It is strongly believed that low levels of these neurotransmitters (or the lack of cellular receptors able to receive the messages) is at the heart of why mood disorders exist. Moreover, depending on which neurotransmitters or neuroreceptors are low, the type and severity of mood disorder can differ. What Reuptake Inhibitors Do Reuptake means reabsorption. It is a normal mechanism by which the body controls how long a nerve signal lasts. However, if you have significantly low levels of a neurotransmitter, reuptake can be a problem as it restricts the volume of neurotransmitters being actively circulated in the brain. To this end, limiting reuptake increases the extracellular concentrations of these chemicals and, by doing so, increases their ability to exert positive effects on your mood. Selective serotonin reuptake inhibitors (SSRIs), SNRIs, NRIs, NDRIs, and SNDRIs are all reuptake inhibitors. They work by blocking the reabsorption (reuptake) of a specific neurotransmitter after it has been excreted from a nerve cell. Types of Reuptake Inhibitors The reuptake inhibitors used to treat mood disorders are classified by the types of neurotransmitter pathway they block. The drugs are able to do this by binding one or several different proteins, called transporters, which are responsible for carrying the chemical between cells. Some of these reuptake inhibitors are classified as selective because they only bind to certain proteins, while others are nonspecific because they bind to a broad range of proteins. The choice of reuptake inhibitor depends largely on the condition being treated and the mechanism of action of the drug. Selective Serotonin Reuptake Inhibitors (SSRIs) SSRIs work by preventing your blood from absorbing some of the serotonin uptake in your brain, which results in higher levels of the feel-good chemical in your brain. They are typically used to treat MDD and anxiety disorders. While SSRIs are sometimes used to treat bipolar depression, there is some controversy as to how effective they are given their potential to exacerbate the rapid cycling of moods. SSRI medications approved for use in the U.S. include: Celexa (citalopram)Lexapro (escitalopram)Luvox (fluvoxamine)Paxil (paroxetine)Prozac (fluoxetine)Zoloft (sertraline) There is also a two-in-one drug called Symbyax which combines Prozac with the antipsychotic Zyprexa (fluoxetine + olanzapine). Symbyax is specially approved for use in treating bipolar depression. Will I Gain Weight If I Take Zyprexa for My Bipolar Disorder? Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) SNRIs block both the serotonin transporter (SERT) and norepinephrine transporter (NET). SNRIs can be used to treat bipolar depression, MDD, ADHD, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), chronic nerve pain, and fibromyalgia. When compared to SSRIs, SNRIs are less likely to exacerbate rapid mood cycling in people with bipolar depression. However, they are commonly used for short-term therapy as prolonged use may trigger a manic or hypomanic episode. SNRI medications approved for use in the U.S. include: Cymbalta (duloxetine), used for depression and chronic painFetzima (levomilnacipran), used to treat depressionPristiq (desvenlafaxine), used for depression and panic disorderSavella (milnacipran), used to treat fibromyalgia Norepinephrine Reuptake Inhibitors Norepinephrine Reuptake Inhibitors (NRIs) work by blocking the action of the norepinephrine transporter (NET). NRIs are commonly used to treat major depressive disorder (MDD), anxiety, panic disorder, narcolepsy, and ADHD. NRI medications approved for use in the U.S. include: Ludiomil (maprotiline), used to treat depression and anxietyStrattera (atomoxetine), used primarily to treat ADHDVivalan (viloxazine), used to treat narcolepsy Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs) NDRIs block the action of both the norepinephrine transporter (NET) and the dopamine transporter (DAT). NDRIs are used for clinical depression, ADHD , and narcolepsy. NDRI medications approved for use in the U.S. include: Focalin (dexmethylphenidate), used to treat ADHD and depressionRitalin (methylphenidate), used to treat ADHDWellbutrin (bupropion), used off-label to treat ADHD Serotonin-Norepinephrine-Dopamine Reuptake Inhibitors (SNDRIs) Serotonin-norepinephrine-dopamine reuptake inhibitors (SNDRIs), also known as triple reuptake inhibitors, blocks the action of the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). SNDRIs were developed to treat depression but can also be used to treat ADHD, chronic pain, and binge-eating disorder associated with obesity. SNDRI medications approved for use in the U.S. include: Effexor (venlafaxine), used to treat major MDD, generalized anxiety disorder (GAD), panic disorder, and social phobiaMazanor (mazindol), used as an appetite suppressantSerzone (nefazodone), used to treat depression Pseudobulbar Affect May Explain Uncontrollable Crying or Laughing A Word From Verywell While all these acronyms can be confusing, the good news is that there are many treatment options available for anxiety, depression, and other mood disorders. Work with your doctor to find a reuptake inhibitor that works best for you. Was this page helpful? Thanks for your feedback! Dealing with racing thoughts? Always feeling tired? Our guide offers strategies to help you or your loved one live better with bipolar disorder. Sign up for our newsletter and get it free. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Psychological Association. Reuptake inhibitor. APA Dictionary of Psychology. Nutt DJ. Relationship of neurotransmitters to the symptoms of major depressive disorder. J Clin Psychiatry. 2008;69 Suppl E1:4-7. PMID: 18494537 Bandelow B, Michaelis S, Wedekind D. Treatment of anxiety disorders. Dialogues Clin Neurosci. 2017;19(2):93–107. PMID: 28867934 Sansone RA, Sansone LA. Serotonin norepinephrine reuptake inhibitors: a pharmacological comparison. Innov Clin Neurosci. 2014;11(3-4):37–42. PMID: 24800132 Fasipe OJ. The emergence of new antidepressants for clinical use: Agomelatine paradox versus other novel agents. IBRO Reports. 2019;6:95-110. doi:10.1016/j.ibror.2019.01.001 Deang KT, Sidi H, Zakaria H, et al. The Novelty of Bupropion As a Dopaminergic Antidepressant for the Treatment of Adult Attention Deficit Hyperactive Disorder. Curr Drug Targets. 2019;20(2):210-219. doi:10.2174/1389450118666170511145628 Malhotra S, King KH, Welge JA, Brusman-lovins L, Mcelroy SL. Venlafaxine treatment of binge-eating disorder associated with obesity: a series of 35 patients. J Clin Psychiatry. 2002;63(9):802-6. doi:10.4088/jcp.v63n0909 Additional Reading McGirr A, Vöhringer PA, Ghaemi SN, Lam RW, Yatham LN. Safety and efficacy of adjunctive second-generation antidepressant therapy with a mood stabiliser or an atypical antipsychotic in acute bipolar depression: a systematic review and meta-analysis of randomised placebo-controlled trials. The Lancet Psychiatry. 2016;3(12):1138-1146. doi:10.1016/S2215-0366(16)30264-4 Vardi K, Warner JL, Philip NS. Effects of antidepressant use and anxiety on psychiatric rehospitalization in bipolar depression. Ann Clin Psychiatry. 2014;26(3):207-216. Vieta E, Garriga M. Adjunctive antidepressants in bipolar depression. The Lancet Psychiatry. 2016;3(12):1095-1096. doi:10.1016/S2215-0366(16)30347-9