To study the neural substrates of insight in OCD by comparing patients with good insight, patients with poor insight and matched healthy controls using functional MRI.

Subjects were recruited from among patients attending OCD clinic, adult psychiatry services and psychiatry ward inpatients of National Institute of Mental Health And Neurosciences (NIMHANS), Bangalore. They were further divided into ‘good insight’ (n=30) and ‘poor insight’ (n=14) using Brown's assessment of belief's scale. Control subjects (n=30) were recruited from consenting volunteers. 3T MRI was used, mental rotation task was paradigm used for fMRI and analysis was done by SPM 8.

Poor insight patients and Ggood insight patients comparison revealed differential activation in Left superior/Medial frontal gyrus (corresponding to the DLPFC). A negative correlation between BABS score and activation of right inferior parietal lobule. Mental Rotation task behavioural data results: OCD patients as a group had significantly lower accuracy compared to healthy controls. Poor insight group had significantly decreased accuracy ratio compared to Good insight group and healthy controls. A negative correlation was noted between BABS score and accuracy ratio, indicating that poorer the insight, greater the errors during the active task.

Insight has been important prognostic factor in OCD. Poor insight patients had specific deficits in left medial frontal gyrus and right inferior parietal lobule as compared to good insight patients and healthy controls. Together, these indicate that insight has a strong neurobiological underpinning in OCD.