Researchers have discovered a brain abnormality in people with obsessive-compulsive disorder (OCD) that may help predict which patients are most likely to respond to treatment with cognitive behavioral therapy (CBT), according to a study published online in Brain Imaging and Behavior.
“The hemodynamic response function (HRF) represents the transfer function linking neural activity with the functional MRI (fMRI) signal, modeling neurovascular coupling,” wrote Jamie Feusner, MD, professor-in-residence of psychiatry and biobehavioral sciences at University of California - Los Angeles Health Sciences, and coauthors. “Since HRF is influenced by non-neural factors, to date it has largely been considered as a confound or has been ignored in many analyses.”
For the study, researchers used fMRI scans to estimate the HRF in 44 adults with OCD and found abnormalities in brain regions including the caudate. After 4 weeks of CBT, however, the abnormalities appeared to normalize. The pattern was not reflected in 25 healthy control subjects who also underwent fMRI scans 4 weeks apart.
Furthermore, pretreatment HRF patterns in the caudate were able to predict a patient’s response to CBT with 86.4% accuracy, researchers reported.
If confirmed in future studies, the findings could help clinicians better decide which patients should receive CBT as a first-line treatment for OCD. Additionally, abnormalities in neurovascular coupling, or how neural activity is linked to blood flow, could represent a new treatment target.
Rangaprakash D, Tadayonnejad R, Deshpande G, O'Neill J, Feusner JD. FMRI hemodynamic response function (HRF) as a novel marker of brain function: applications for understanding obsessive-compulsive disorder pathology and treatment response. Brain Imaging and Behavior. 2020 August 6;[Epub ahead of print].