Schizophrenia

Members: Mu Hsuan Ho, Helen (Bomin) Kim, Erin Macpherson, Bart Maracewicz, Biftu Saleh and Saerom Youn

Schizophrenia is a severe neurological disorder that affects roughly 0.7% of the global population. The symptoms are categorized into three main clusters; positive symptoms, involving hallucinations and delusions, negative symptoms comprising of poor emotional responsiveness and general lack of interest, and cognitive symptoms including poor executive function, disorganized thinking and impaired attention. Several genetic and environmental factors have been proven to be involved in the development of schizophrenia. Genome-wide linkage analyses of various ethnic groups indicate that chromosome4 and chromosome6 contain the candidate genes. Further, Neureglin1 was found to be involved in cannabinoid-induced schizophrenia, while Notch4 lead to decreased cognitive function. Environmental factors such as season, toxins and nutrition also play a role in activating the genes underlying the onset of schizophrenia. Many pathways and theories have been suggested to explain the neurological mechanisms of schizophrenia. According to the dopamine hypothesis, hyperactivity of dopamine in the mesolimbic pathway triggers the positive symptoms while hypoactivity in the mesocortical dopamine pathway underlies the negative symptoms. Reduced action of glutamate and NMDA receptors additionally play a role in the onset of schizophrenia. Further, the disorder involves certain structural changes of the cortex and neuronal networks, suggesting that schizophrenia may be a developmental disorder. Research suggests that psychological maladaptations such as cognitive deficiencies and decreased emotional responsiveness may be causal factors in the development of the disorder. Activation of the HPA axis in childhood trauma, negative affective priming and overly vivid mental imagery may increase the likelihood of later onset schizophrenia. Like many other disorders, the diagnosis of schizophrenia involves the DSM-V1-TR and the ICD-10, which provide a national standard criterion for diagnosis. According to the DSM-V1-TR, schizophrenia is an Axis 1 disorder with four sub-classifications including paranoid, disorganized, catatonic and undifferentiated. As for medication, antipsychotic drugs are the first line of treatment, although they primarily target positive symptoms and have many side effects. Other management approaches include cognitive behavioral therapy, social skills rehabilitation and family education programs.

= 1. History (B. Maracewicz) = 1.1 First Reported Cases 1.2 Coining the Term 1.3 Controversies and Revised Definitions

= 2. Epidemiology and Symptoms (B. Saleh) = 2.1 Epidemiology 2.2 Positive Symptoms 2.3 Negative Symptoms 2.4 Cognitive Symptoms

= 3. Causes (H. Kim) = 3.1 Genetic Factors 3.2 Environmental Influence

= 4. Neurological Mechanisms (S. Youn) = 4.1 Dopamine Hypothesis 4.2 Serotonin 4.3 Glutamate and NMDA Receptors 4.4 Structural Changes in the brain 4.5 Neurodevelopmental hypothesis 4.6 Neurodegenerative hypothesis

= 5. Psychological Mechanisms (B. Maracewicz) = 5.1 Studied Mechanisms 5.2 Current Research

= 6. Diagnosis (M. H. Ho) = 6.1 Diagnosis of Schizophrenia 6.2 Subtypes 6.3 Interviewing and assessment 6.4 Misdiagnosis

= 7. Treatment and Management (E. Macpherson) = 7.1 Medication 7.2 Psychosocial Interventions 7.3 Management challenges and long-term prognosis

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