Emotional blunting describes an indifferent, unresponsive affect and inability to feel emotions experienced by people with major depressive disorder (MDD) treated with antidepressants.1,2 Dampening of dopaminergic and noradrenergic input to the prefrontal cortex is thought to play an important role,3 and management can be guided by understanding the neuropathophysiology.3
A negative impact on patient outcome
Emotional blunting is a residual symptom of MDD, which is a symptom experienced by patients with MDD despite antidepressant therapy. Such patients are at risk of relapse.1,4
Emotional blunting can impact everyday patient function and prevent a full functional recovery.5 More severe emotional blunting is associated with a poorer quality of remission.6
46% of patients on antidepressants report emotional blunting6
Nearly half of patients on all types of monoaminergic antidepressants report emotional blunting,6 and it is associated with serotonin reuptake inhibitor (SSRI) therapy as follows:5
- among 161 patients, 46% reported a narrowed range of affect, 21% reported an inability to cry, and 19% reported apathy7
- a cross-sectional study of 117 patients revealed that approximately 30% of patients reported some form of apathy8
What causes emotional blunting?
Higher doses of SSRI are more likely to cause emotional blunting9
The primary effect of SSRIs is reduced processing of negative stimuli rather than increased positive stimuli.2
Emotional blunting is related to SSRI dose,9 and possibly serotonergic effects on the frontal lobes and/or serotonergic modulation of midbrain dopaminergic systems projecting to the prefrontal cortex (PFC).9 By enhancing serotonergic transmission, SSRIs can activate GABA interneurons, thereby dampening the noradrenergic and dopaminergic input.10
Dorsolateral PFC:
- is primarily associated with “cognitive” or “executive” functions11
- appears to play a role in regulating negative emotion through reappraisal/suppression strategies12,13
- lesions are associated with significantly higher MDD scores than for head injuries not involving the PFC11
Dorsolateral PFC appears to play a critical role in MDD through a defect in regulation of negative affect
Lowering SSRI dose9 or changing antidepressant are therapeutic options
Ventromedial PFC:
- is largely ascribed “emotional” or “affective” functions11
- lesions are associated with significantly lower MDD scores than for brain injuries not involving the PFC11
- is hyperactive at rest and decreases in activity during symptom remission12
Imaging studies suggest a critical link between the automatic processing of emotional signals in the amygdala and the regulation of this activity in the frontal cortex.15
Options to resolve emotional blunting are therefore to:
- lower the dose and/or discontinue the SSRI9
- change the antidepressant to one with a different profile that might improve the patient’s emotional response10
PFC: prefrontal cortex
BE-NOTPR-0035; approval date 08/2021
