Study Finds High Rates of Emotional Blunting Among Depression and Bipolar Disorder Patients

Major depressive disorder affects hundreds of millions globally and saw an estimated 27% increase in prevalence in 2020 due to the COVID-19 pandemic, which introduced stress, isolation, and economic challenges.

The onset of major depression stems from multiple factors, including biological, genetic, environmental, and behavioral influences. Childhood adversities such as abuse and neglect are notable risk factors, often linked to poorer treatment outcomes and a higher likelihood of recurrence.

Emotional blunting, characterized by apathy, loss of motivation, and emotional numbness, is a common aspect of depression. It is particularly prevalent during acute depressive episodes and may persist even after treatment. Some antidepressants, especially selective serotonin reuptake inhibitors, are known to cause emotional blunting, which can disrupt daily life; up to 40% of patients have considered stopping these medications due to this side effect.

The study, led by Narak Chadbunchachai and colleagues at Khon Kaen University, aimed to explore the prevalence of emotional blunting among patients with mild to moderate depressive symptoms or in remission, and its correlation with childhood adversity. They hypothesized that remitted patients with more adverse childhood experiences would report greater emotional blunting.

The study involved 106 outpatients who were diagnosed with either major depressive disorder (61 participants), persistent depressive disorder (19), or bipolar I disorder (26). The average age of participants was 29, with 73% being women. To participate, patients needed to show mild to moderate symptoms, not be at risk of suicide, and have been on the same antidepressant for at least a month. Half qualified as being in remission, meaning they exhibited few remaining symptoms based on a clinician-rated scale.

Participants answered a screening question about emotional numbness over the past six weeks, followed by a 26-item questionnaire assessing the intensity of emotional blunting. According to the screening question, 56% of participants reported some level of emotional blunting. Specific rates included 51% for major depressive disorder, 63% for persistent depressive disorder, and 62% for bipolar disorder; these differences were not statistically significant. Most participants scored in the “minimal” range for emotional blunting, with 36% in the “mild” range and one person in the “severe” range.

Emotional blunting was reported by 45% of participants in remission and 66% of those not in remission. Severity of previous depressive symptoms and mood episode history correlated with more intense emotional blunting, though these associations were modest. Among remitted patients, emotional blunting was not related to symptom severity.

Links to childhood adversity were limited and mostly weak. One aspect of emotional blunting—apathy—was stronger among those reporting frequent emotional or physical abuse in childhood and less familial emotional support. For remitted patients, connections between apathy, emotional abuse, and low emotional support were maintained.

The authors noted, “Remission was associated with a lower prevalence of emotional blunting; however, the prevalence remained high even among remitters.” While the study adds valuable insights into depression, its design does not allow for causal conclusions. The assessment of childhood experiences relied on current recollections, which may have introduced recall bias. Furthermore, since all participants were on antidepressants and over 90% attributed their emotional blunting to their medication, the study could not differentiate between lingering symptoms of depression and side effects of treatment.

The study's findings are documented in the paper titled “Prevalence of emotional blunting and its association with childhood adverse experiences in depressive episodes,” authored by Narak Chadbunchachai, Papan Vadhanavikkit, Sirinapa Aphisitphinyo, Pattharee Paholpak, Nawanant Piyavhatkul, Parinda Pienroj, and Pongsatorn Paholpak.