Do SSRIs cause Emotional Blunting?
Hot Take Tuesday with Dr. Fu
Emotional blunting and antidepressants: it's a hot topic. I should probably say at the outset that no matter the reported side effect or adverse effect, it is better to switch or stop a medication for a patient if they do not believe in it, with the possible exceptions of some cases in schizophrenias and bipolar disorders where there is a very clear medical indication.
Do not give medications to patients who do not believe in them. It is a fool's errand. Switch or offer alternatives. Consider alternatives with a totally different mechanism of action. Really, really consider nonpharmacological treatments. We do not really know enough about the brain and the mind and our medications to be very confident about what we're dealing with.
That being said, I'd like to wax poetic. Before we offer any real solutions to a problem, we must understand the problem (reported emotional blunting). Here is some background information:
Understanding the Landscape: Illness, Medication, and Blunting
What do we know about the role of serotonin in mammals? It regulates motor activities, sleep-wake cycle and Rapid Eye Movement (REM) sleep, feeding behaviors, aggression, memory plasticity, and of course depression and anxiety (as detailed in Serotonin in Animal Cognition and Behavior. Int J Mol Sci. 2020 by Bacqué-Cazenave J, et al.). We also know that we measure antidepressant efficacy by how long it takes for a rat to stop trying to swim in a situation where swimming is not allowing the rat to leave.
First, the most likely explanation for reported emotional numbing during antidepressant treatment is simply the disease process itself.
What do we know about depressive disorders? Patients feel anhedonia and in severe cases can feel nothing at all.
What do we know about borderline conditions? Patients will experience feelings of emptiness or numbness, or may present with an alexithymia that may be indicative of numbness and lack of access to the internal emotional state.
What do we know about trauma disorders? Patients can be stuck in negative emotions, or they may be unable to feel positive emotions.
What do we know about anxiety disorders? Patients are often focused on anxiety and fear feelings, and may feel this in place of others emotions.
In a 2022 paper from Peters et al., adult outpatients identified with Major Depressive Disorder (MDD) showed that only under 6% of the participants had more emotional blunting post treatment. Reported emotional blunting was associated with poorer outcomes such as depressive symptoms, suicidal ideation, and sexual function, but "these correlations were nearly identical in the placebo group." Also, at the final assessment, 6% of patients in the placebo group had increased emotional blunting, vs. 5.56 % in the venlafaxine group. Emotional blunting change scores were not statistically significant between venlafaxine and bupropion. Emotional blunting change, nor the proportion of patients with worsening emotional blunting, did not reach statistical significance when comparing bupropion with escitalopram (for the latter, 3.15% with escitalopram vs. 1.53% with bupropion).
So, what's going on here? Hot takes follow…
In my personal clinical practice, the amount of patients who complain of any problematic or persistent SSRI induced emotional blunting is 0 or near 0 across years.
This is rather divergent from the research data of patients complaining of emotional blunting in depressive disorders, and of internet/other anecdotal experiences of patients complaining of emotional blunting specific to Serotonin Reuptake Inhibitor (SRI) treatments. What could account for this?
Well, let's put forward right away that I may simply be a bad psychiatrist who does not appropriately elicit the information from my patients. This would, however, require the patients to be lying to be when I ask about side effects or problems with the medications, and I do so aggressively. I do not, however, specifically suggest that emotional blunting is a side effect of the antidepressant, because I don't think the actual data we have supports this conclusion better than the conclusion that it is a result of the mental disorder (see prior papers, and a little more on that in a moment).
It should be noted that I only prescribe SRIs for depression when I can confirm a clear diagnosis of a Major Depressive Episode (MDE) of MDD, recurrent, with neurovegetative symptoms (e.g., significant changes in sleep, appetite, energy, or psychomotor activity). In cases where patients have an apparent MDE but no history of recurrence nor history of neurovegetative symptoms, I am less willing to prescribe SRIs unless the patient is actively requesting it. The other situations where I prescribe SRIs: moderate to severe trauma disorder, moderate to severe anxiety disorders, and OCD.
Consider that in classical MDD, recurrent, with neurovegetative symptoms (basically melancholic depression?), REM sleep is prolonged and maybe dysregulated. SSRIs inhibit REM sleep. If your REM sleep is dysregulated before the SSRI is prescribed, maybe that's a good thing? If your REM sleep is NOT dysregulated... maybe you aren't supposed to get SSRIs/SRIs?
I have yet to see a patient with moderate to severe major depression, anxiety, panic disorder, OCD, or trauma disorder actually complain upon initiation of an effective treatment. Emotional blunting? Whether or not that is present, most people would rather have that then the horrors of uncontrolled symptoms from such conditions. In such individuals, perhaps the correctly prescribed SSRI is addressing an off balance/dysregulated mind-brain-body state, appropriately.
Who then is finding the "emotional blunting" purportedly induced by an antidepressant to be something worse than the disease? I have started to wonder whether antidepressants specifically induce reported worsening emotional blunting as a direct effect of the medication specifically when it is being prescribed to individuals whose depression is the result of a personality pathology.
Perhaps when you prescribe an SRI to someone who has normal brain functioning with regard to whatever pathology is involved in major depression and similar syndromes (whatever this may be, Hypothalamic-Pituitary-Adrenal (HPA) axis, Brain-Derived Neurotrophic Factor (BDNF) production, neuroplasticity, neuroinflammation), this re-regulates that system.
Perhaps when you prescribe SRI in patients who LACK such pathology, including healthy patients, you produce emotional blunting. Perhaps in "depressions" that are primarily the product of personality pathology, interpersonal conflicts, or social stressors, the drug acts on the mind-brain-body system in a manner that flattens things: reduced aggression, reduced emotional fluctuation, increased tendency to see desperate situations with a steel-eyed and flattened demeanor (think the forced swim test).
Perhaps in some small group of people, they are accustomed to, or even enjoy their symptoms, including but not limited to emotional fluctuations, aggression, cravings and dissatisfactions, and severe highs and lows not attributable to a bipolar disorder.
Perhaps flattening these experiences is not welcome for a person who, at baseline, has difficulty perceiving their internal functioning as pathological in any meaningful way!
In those who do perceive their aggression, emotional fluctuation, and tendency to give up as a problem, perhaps the effects of SRI on the non-majorly-depressed person is actually welcome. Patients who can't sleep and eat also appreciate the sedating and appetite stimulating qualities of olanzapine. Those who want to stay awake and avoid eating do not appreciate olanzapine!
So, maybe it's a matter of applying the right medication to the right patient. But in the end, returning to my points in the first section, I think the problem is one of therapeutic alliance rather than specific medications. If you are actively working with the patient to optimize the degree to which both you and the patient feel you are using the right medications for the right reasons and in acceptance of the right side effects, the presence or absence of emotional blunting becomes less important than what you are both doing to progress the treatment.
- Dr. Fu
Citations:
Peters EM, Balbuena L, Lodhi RJ. Emotional blunting with bupropion and serotonin reuptake inhibitors in three randomized controlled trials for acute major depressive disorder. J Affect Disord. 2022 Dec 1;318:29-32. doi: 10.1016/j.jad.2022.08.066. Epub 2022 Aug 24. PMID: 36029876.
Bacqué-Cazenave J, Bharatiya R, Barrière G, Delbecque JP, Bouguiyoud N, Di Giovanni G, Cattaert D, De Deurwaerdère P. Serotonin in Animal Cognition and Behavior. Int J Mol Sci. 2020 Feb 28;21(5):1649. doi: 10.3390/ijms21051649. PMID: 32121267; PMCID: PMC7084567.