Mechanisms of SSRI Therapy and Discontinuation.
Trevor Sharp, Helen M Collins
Current Topics in Behavioral Neurosciences 2024 DOI: 10.1007/7854_2023_452 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Anxiety Depression Ketamine Neuroplasticity Serotonin |
| Keywords | Antidepressants Citalopram Discontinuation Fluoxetine Paroxetine Psychedelics Ssris Serotonin 5-HT Receptors Withdrawal |
| Citations | 40 |
| Key findings | SSRIs' therapeutic effects are now thought to involve complex downstream signaling that triggers neural plasticity, but evidence causally linking plasticity to behavioral effects is missing, and the mechanisms of SSRI discontinuation syndrome remain poorly understood. |
Abstract
SSRIs are one of the most widely used drug therapies in primary care and psychiatry, and central to the management of the most common mental health problems in today's society. Despite this, SSRIs suffer from a slow onset of therapeutic effect and relatively poor efficacy as well as adverse effects, with recent concerns being focused on a disabling SSRI discontinuation syndrome. The mechanism underpinning their therapeutic effect has long shifted away from thinking that SSRIs act simply by increasing 5-HT in the synapse. Rather, a current popular view is that increased 5-HT is just the beginning of a series of complex downstream signalling events, which trigger changes in neural plasticity at the functional and structural level. These changes in plasticity are then thought to interact with neuropsychological processes to enhance re-learning of emotional experiences that ultimately brings about changes in mood. This compelling view of SSRI action is underpinning attempts to understand fast-acting antidepressants, such as ketamine and psychedelic drugs, and aid the development of future therapies. An important gap in the theory is evidence that changes in plasticity are causally linked to relevant behavioural effects. Also, predictions that the SSRI-induced neural plasticity might have applicability in other areas of medicine have not yet been borne out. In contrast to the sophisticated view of the antidepressant action of SSRIs, the mechanism underpinning SSRI discontinuation is little explored. Nevertheless, evidence of rebound increases in 5-HT neuron excitability immediately on cessation of SSRI treatment provide a starting point for future investigation. Indeed, this evidence allows formulation of a mechanistic explanation of SSRI discontinuation which draws on parallels with the withdrawal states of other psychotropic drugs.
Comparable studies
Other narrative reviews on ketamine for anxiety, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A Consensus Statement on the Use of Ketamine in the Treatment of Mood Disorders | 2017 | Review and consensus statement | |
| KETAMINE'S MECHANISM OF ACTION: A PATH TO RAPID‐ACTING ANTIDEPRESSANTS | 2016 | Review | |
| Eradicating Suicide at Its Roots: Preclinical Bases and Clinical Evidence of the Efficacy of Ketamine in the Treatment of Suicidal Behaviors | 2018 | Review | |
| Predictors of Response to Ketamine in Treatment Resistant Major Depressive Disorder and Bipolar Disorder Patients with treatment-resistant depressive symptoms as part of major depressive... | 2018 | Narrative review | |
| Ketamine as a Fast Acting Antidepressant: Current Knowledge and Open Questions | 2013 | Review |