Can brain activity predict responses to medication and therapy for depression?

February 18, 2025

Original Title:
Response Inhibition and Predicting Response to Pharmacological and Cognitive Behavioral Therapy Treatments for Major Depressive Disorder: A Canadian Biomarker Integration Network for Depression Study

Link: https://pubmed.ncbi.nlm.nih.gov/35032682

Depression not only affects mood but can also impact cognitive functions like response inhibition—our ability to control impulses. Recent research suggests that response inhibition may influence how individuals respond to antidepressant medication, but less is known about its role in non-drug treatments like cognitive behavioural therapy (CBT).

To explore this, CAN-BIND researchers, including Dr. Prabhjot Dhami and Dr. Faranak Farzan, analyzed data from two studies: one involving 65 patients treated with the antidepressant medication, escitalopram, and another involving 41 patients receiving CBT for depression. The researchers also included 25 individuals without a diagnosis of depression in the analysis as a comparison group. All participants included in the analysis completed a task designed to measure their ability to control impulses (i.e. response inhibition). While completing the task, their brain activity was also recorded using electroencephalography (EEG), a technique that measures electrical signals in the brain.

The results showed that P3 amplitude, a brain signal linked to impulse control, played an important role in predicting treatment success. Individuals who had a stronger P3 signal before starting treatment were more likely to experience a greater reduction in their depression symptoms, whether they received medication or therapy. Additionally, the researchers found that before treatment even began, individuals who experienced improvement in their depression symptoms had a stronger P3 signal compared to both those whose symptoms did not improve and those without depression.

These findings suggest that the ability to control impulses may be important for successful treatment of major depressive disorder (MDD) with either medication or therapy. Further, brain activity related to impulse control could serve as a useful predictor of treatment response, helping to guide more personalized approaches to depression care.

Citation: Dhami P, Quilty LC, Schwartzmann B, Uher R, Allen TA, Kloiber S, et al. Response Inhibition and Predicting Response to Pharmacological and Cognitive Behavioral Therapy Treatments for Major Depressive Disorder: A Canadian Biomarker Integration Network for Depression Study. Biological Psychiatry: Cognitive Neuroscience and Neuroimaging 2023;8:162–70. https://doi.org/10.1016/j.bpsc.2021.12.012