Can PET/CT imaging advance our understanding of the neurobiology of schizophrenia?

Abstract

Schizophrenia is a severe psychiatric disorder affecting approximately 1% of the population worldwide. The disorder is ranked among the top 10 causes of disability worldwide. New drugs and therapeutic interventions are therefore warranted to reduce symptomatology, delay onset, or potentially cure this devastating disorder. This would greatly help individuals in the early stages of schizophrenia. Although schizophrenia has a strong genetic basis (80%), owing to the nature of the neurobiological and genetic heterogeneity of the disorder, its a etiology has remained elusive. Schizophrenia is characterized by psychotic symptoms, emotional disturbances, and cognitive dysfunction. These symptoms may be the result of dopamine dysregulation in individuals with schizophrenia [1]. Advances in anatomical and functional imaging have provided useful insights into the neurobiological mechanisms of schizophrenia, enabling brain function to be studied at a molecular level. Recent imaging investigations using computed tomography (CT) and magnetic resonance imaging (MRI) have reported grey matter reduction and ventricular enlargement in schizophrenia [2], and functional MRI studies have reported abnormalities in the frontotemporal and frontoparietal function regions. Diffusion tensor imaging is used to provide an insight into white matter tract integrity and regional cerebral connectivity. Recent studies show abnormalities in frontoparietal and left cerebellar white matter tract integrity in schizophrenia [3]. Positron emission tomography (PET) is an effective functional imaging technique that uses radioactive tracers to help identify regions associated with brain function. It has been used to detect levels of dopaminergic activity in individuals with major psychiatric disorders. The most consistent findings from adult-onset schizophrenia studies are differences in dopaminergic content in the prefrontal cortex (PFC), anterior cingulate gyrus, and hippocampus between normal controls and patients with schizophrenia. Several PET tracers have been used to identify brain