Summary: A new neuroimaging study finds that people with obsessive‑compulsive disorder (OCD) experience stronger distress and show greater activation in emotion‑related brain regions when viewing OCD‑triggering images than their unaffected siblings. Siblings showed less distress but recruited attention‑related brain areas more strongly, suggesting compensatory brain mechanisms that could protect against developing OCD.
Source: Elsevier
People with OCD react more strongly to disorder‑related images than their unaffected siblings, while siblings engage extra attentional brain resources that may help regulate emotional responses.
Researchers report in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging that patients with obsessive‑compulsive disorder displayed higher subjective distress and increased activity in emotion‑related areas of the brain when exposed to images designed to provoke OCD‑related feelings—compared with unaffected siblings and unrelated healthy control participants. Unaffected siblings, although less distressed than patients, showed elevated activation in brain regions associated with attention and cognitive control when attempting to down‑regulate negative emotions, a pattern that may reflect compensatory strategies that protect against developing OCD.
The study highlights a meaningful difference in brain function between individuals currently affected by OCD and family members who share genetic risk but do not have the disorder. Anders Thorsen, MSc, of Haukeland University Hospital (first author), emphasized that the brain patterns observed in OCD patients appear to reflect the active illness rather than inherited or familial vulnerability. This distinction matters for researchers seeking reliable neural markers of risk for OCD, a condition known to have substantial genetic influences. Specifically, measures of emotion regulation and related brain activity may not serve as a straightforward endophenotype (a heritable biomarker) for identifying people at genetic risk of OCD.
Study design and procedures
The investigators recruited 43 unmedicated adults diagnosed with OCD, 19 of their unaffected siblings, and 38 unrelated healthy control participants. All participants underwent 3T functional magnetic resonance imaging (fMRI) while completing an emotion regulation task. During scanning they viewed three types of images: neutral, fear‑inducing, and OCD‑related stimuli (for example images that elicit urges to wash, check, or neutralize perceived threats). For each image participants either simply viewed it (natural appraisal) or used cognitive reappraisal strategies to reduce their negative emotional response. After each picture they rated their level of distress.
Key findings
Responses to fear‑inducing images were similar across the three groups, both in reported distress and in brain activation patterns. The major differences emerged for OCD‑related stimuli. Patients with OCD reported significantly higher distress when viewing those images and showed increased activation in emotion‑processing regions, including the amygdala and dorsomedial prefrontal cortex, during provocation and regulation phases. Unaffected siblings reported distress levels similar to healthy controls and substantially lower than patients. In brain imaging data, siblings’ activation often fell between the levels seen in patients and controls. Importantly, siblings exhibited higher activation in left temporo‑occipital regions and stronger fronto‑limbic connectivity during attempts to regulate emotion in response to OCD‑related pictures.
Interpretation
Those patterns suggest that unaffected siblings may recruit additional attentional and visual processing resources when asked to down‑regulate responses to disorder‑relevant cues. Editor Cameron Carter, MD, noted that relatives appear to engage brain regions that “work harder” to normalize responses to OCD‑related stimuli. The authors propose that this heightened recruitment of attention‑related circuitry could represent a compensatory process that helps redirect focus away from distressing thoughts or images and contributes to resilience against developing OCD despite familial risk.
Implications and next steps
The findings imply that abnormal emotion regulation activity observed in OCD patients is likely a state marker of the illness rather than a stable familial trait that identifies genetic risk. Future longitudinal studies that follow families over time will be important to determine whether the compensatory patterns seen in unaffected siblings predict resilience or change during development and whether they can inform prevention strategies.
This research compared behavioral ratings and fMRI activation during an emotion provocation and regulation task in three groups: unmedicated adults with OCD, their unaffected siblings, and unrelated healthy control participants. The investigators measured distress ratings and examined activation in predefined brain regions during both natural appraisal and cognitive reappraisal of neutral, fear‑inducing, and OCD‑related images. The pattern of results suggests that emotion regulation‑related brain activity is not a robust familial endophenotype for OCD; instead, unaffected siblings appear to show distinct activation consistent with compensatory cognitive control.
Original study authors include Anders L. Thorsen and colleagues. The study appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging and contributes to our understanding of how familial risk and resilience for obsessive‑compulsive disorder may be reflected in brain function.
Abstract (concise summary)
Background: Previous work has proposed neuroimaging endophenotypes for OCD during executive tasks. This study tested whether behavioral and neural responses during emotion processing and regulation could serve as an endophenotype.
Methods: Forty‑three unmedicated OCD patients, 19 unaffected siblings, and 38 healthy controls performed an fMRI emotion regulation task with neutral, fear‑inducing, and OCD‑related images. Participants either naturally appraised or cognitively reappraised images; distress ratings and region‑of‑interest activation were analyzed.
Results: Siblings reported distress similar to healthy controls and lower than patients during provocation. Patients showed higher amygdala and dorsomedial prefrontal cortex activation for OCD‑related stimuli; siblings were intermediate but not significantly different from either group. Siblings demonstrated higher left temporo‑occipital activation and greater fronto‑limbic connectivity during OCD‑related regulation compared with patients.
Conclusions: Unaffected siblings do not share the elevated distress or amygdala activation seen in patients, but they display distinct activation in regions that may support compensatory cognitive control. These results indicate that emotion regulation is unlikely to be a strong endophenotype for OCD and offer insight into familial risk and resilience.