Subcortical and cortical morphological anomalies as an endophenotype in obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Genetics
• Psychiatry

Background:

• Endophenotypes offer a way to accelerate genomic discovery in obsessive-compulsive disorder (OCD).
• Identifying shared neuroanatomic changes in individuals with OCD and their at-risk relatives can illuminate the disorder's underlying biology.

Purpose of the Study:

• To identify shared neuroanatomic alterations in adult and adolescent patients with OCD and their unaffected siblings at genetic risk.
• To compare these neuroanatomic changes with those in healthy controls.

Main Methods:

• Surface morphology of the striatum, globus pallidus, and thalamus was defined.
• Cerebral cortical thickness was measured.
• Comparisons were made between OCD patients, unaffected siblings, and healthy controls.

Main Results:

• Patients with OCD exhibited significant surface expansion in the caudate, thalamus, and right orbitofrontal cortex compared to controls.
• Unaffected siblings showed similar expansion, particularly in the ventromedial caudate, right pulvinar thalamic nucleus, and right orbitofrontal cortex.
• Both groups displayed increased thickness in the right precuneus and left medial temporal cortex.

Conclusions:

• Shared neuroanatomic changes in the orbitofrontostriatal and posterior brain circuitry are evident in individuals with OCD and their at-risk relatives.
• These identified brain alterations represent promising endophenotypes for advancing genomic discovery in OCD.
• The findings highlight the involvement of specific brain networks in the pathophysiology of OCD.