Schizophrenia as a functional disconnection problem in brain development

Schizophrenia as a Functional Disconnection Problem in the Brain

Studies by Schmitt et al. (2011) offer conclusive evidence that schizophrenia is a neurodevelopmental disorder. While schizophrenia can be exacerbated by both genetic and environmental factors, the disease has been conclusively linked to developmental disconnectivity of the prefrontal cortex of the brain via neural imaging studies.

Schizophrenia is a brain disorder that directly affects the way an individual talks, acts, and perceives the world. Schizophrenic patients often exhibit a loss of contact with reality and an inability to perceive their environment correctly. These individuals may see and hear things that are not real and these symptoms make it very difficult for patients to live and navigate normal daily tasks. Scientists have studied that onset of schizophrenia, finding that it frequently appears during the teenage to young adult years and is more severe in men than women. In recent years studies have shown that the disorder may be directly linked to brain development, and as an individual matures a functional disconnect occurs in the areas of the brain that control both cognition and emotion.

Schmitt et al. (2011) report that, "Meta-analyses of structural magnetic resonance imaging (sMRI) studies reveal gray matter volume deficits in different brain regions in schizophrenic patients." These gray matter areas are often lesions that produce a disconectivity between essential areas of the brain that control both cognition and emotion. The authors completed this work through image-guided investigations, including transcranial, magnetic stimulation (TMS), electroencephalography (EEG), and magnetoencephalography (MEG). The images produced gave investigators information regarding the functioning of brain connectivity and exactly how it related to the disease of schizophrenia. Results show that poorly functioning brain ventricles often appear in imagining of schizophrenic brains. The frontal lobe of the brain, which is responsible for cognitive tasks such as planning, reasoning, and decision-making, is often found to have lower functioning. The hippocampus and temporal lobes of the brain also show abnormalities and, as Schmitt at al. (2011) report, animal models with schizophrenic symptoms show lesions on these areas of their brains in post-mortem investigations.

Studies completed by Schmitt et al. (2011) reviewed both EEG and MEG imaging of patients diagnosed with schizophrenia. The team notes that, "a common pattern of the different brain oscillations in schizophrenia patients is a reduction in amplitude and altered phase synchronization in all frequency bands (with emphasis on the beta and gamma band activity) at rest, during sensory processing and cognitive tasks" (Schmitt et al., 2011). While imaging studies make it clear that neural disconnectivity is present in schizophrenic patients it remains unclear exactly what causes specific individuals to develop the disorder. Schmidt et al. note that, "in theory, the underlying biological and pathophysiological agent of schizophrenia is a dysfunction of NMDAR with a consecutive reduced synaptic and cellular plasticity. This would affect long-range connections in the developing brain, induce abnormalities in different neurotransmitter systems (dopamine, serotonin, acetylcholine, GABA).

In further studies of mental disorders and neural pathway functionality, Baeken and De Raedt (2011) found that transcranial magnetic stimulation (TMS) has a direct effect on patients with depression, alleviating symptoms and often restoring improved neurotransmission. The team noted that, "successful rTMS treatment seems to result in a cascade of neurobiological changes in brain areas linked with the stimulated area." They also note that these treatments seem to work effectively in conjunction with psychotropic medications. Studies such as these seem to indicate that TMS could possibly used to stimulate areas of the brain in order to help alleviate or correct symptoms of major mental health disorders such as schizophrenia and depression.