Neuroanatomical, Neurochemical, and Neurodevelopmental Basis of Obsessive-Compulsive Symptoms in Schizophrenia

Abstract

The prevalence of the obsessive-compulsive symptoms in schizophrenia (OCSS) appears to be higher than that expected on the basis of comorbidity rates. Review of brain abnormalities in schizophrenia and obsessive-compulsive disorder (OCD) reveals involvement of similar regions namely the frontal lobe, the basal ganglia, the thalamus, and the cerebellum, in both the disorders. Neurodevelopmental etiopathogenesis has been proposed to explain schizophrenia as well as OCD. Significant overlap in neurotransmitter dysfunction (serotonin, glutamate, and dopamine) has been documented between schizophrenia and OCD. The New-onset obsessive-compulsive (OC) symptoms have been reported with the use of atypical antipsychotics in the schizophrenia patients In this background, OCSS is an emerging area of recent interests. This article attempts to review the literature on the neurobiology of OCSS. Neuroimaging, neuropsychological, and neuromotor abnormalities in OCSS discussed in the context of neurodevelopmental etiopathogenesis suggest glutamate abnormalities in OCSS. Atypical antipsychotic induced OCSS points towards the possible roles of glutamate and serotonin. Dopamine may be responsible for the beneficial role of antipsychotics in the treatment of OCD. In summary, we propose that glutamate, serotonin, and dopamine abnormalities may be the probable basis for OCSS.

Donepezil for Compulsive Behavior in Degenerative Dementia: Case Series

“…Unstable prefrontal glutamatergic system with hyperglutamatergic orbitofrontal (OFC) and hypoglutamatergic dorsolateral prefrontal (DLPFC) regions has been theorized to be the pathophysiology behind the schizo-obsessive disorder. 11) Similar glutamate mediated degenerative process involving the DLPFC along with striatal circuits would be resulting in the symptom presentation in our cases.…”

The Neurobiological Underpinnings of Obsessive-Compulsive Symptoms in Psychosis, Translational Issues for Treatment-Resistant Schizophrenia

“…The association between genes affecting the glutamatergic, dopaminergic, and serotoninergic neurotransmission could suggest that neurotransmitters overlap within the cortico-striatal-thalamo-cortical circuit (CSTC) in both OCD and schizophrenia conditions [57]. Brain abnormalities as unveiled by imaging studies may involve common regions in schizophrenia and OCD: the frontal lobe, the basal ganglia, the thalamus, and the cerebellum [59]. Functional neuroimaging studies have shown reduced neural activation in the dorsolateral prefrontal cortex (DLPFC) and right caudate of schizophrenia patients with and without OCS compared to healthy controls [60,61].…”

Augmentation with antidepressants in schizophrenia treatment: benefit or risk

“… 96 , 97 It was strongly suggested that the serotoninergic antagonism of second-generation antipsychotics, which results in an imbalance between serotoninergic and dopaminergic system, contributes to this side effect; 98 alteration or dysfunction of glutamatergic and dopaminergic neurotransmission might also be involved. 99 , 100 Patients with comorbid OCS in schizophrenia are generally suffering from more neurocognitive impairment, more severe psychosis, and treatment resistance. 101 , 102 …”