Vital processes that facilitate daily function and social cognition are localized in the brain. Brain chemistry is especially important in maintaining a homeostatic state through the usage of neurotransmitters as chemical messenger molecules in both the central and peripheral nervous system. When these processes are disrupted, widespread abnormalities causing impairment may ensue. Schizophrenia is a chronic and debilitating mental disorder that manifests itself in characteristic ways that include: emotional dysregulation, interrupted thought processes, delusions and paranoia[1]. Research in this area has led to an increasingly reliable and valid diagnostic criteria for the identification of this mental disorder, as outlined by the most recent version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)[2]. Although the American Psychiatric Association asserts that the changes made will increase its validity, the DSM-5 has not been widely accepted by North American physicians who are still using DSM-IV for clinical diagnoses of schizophrenia. Unfortunately, schizophrenia is prevalent in modern society, affecting 15 in 100,000 people, but the incidence of the disorder varies across populations and environments. More specifically, it is associated with child rearing in urban environments and is also linked to cananbis abuse. Further research in the field has identified genetic factors that include mutations in COMT Val and NRG1 genes that can contribute to the Schizophrenic phenotype. The identification of these mechanisms has propelled the area of treatment in a forward direction, allowing for the expansion of pharmacotherapy options available for affected individuals. Because schizophrenia disrupts emotional and social skill acquisition, psychosocial treatment has proven to be successful. A promising area of study involves virtual-reality treatments that aim to integrate skill training and improvements in social cognition into every day life scenarios. Despite our understanding, the nature of schizophrenia is still unclear to us. Modern advance in technology has led to new insights that will allow us to further this understanding.

1. National Institute of Mental Health. What Is Schizophrenia? (2009) - NIH Publication.
2. American Psychiatric Association. Schizophrenia Fact Sheet (DSM-5). (2013) - American Psychiatric Publishing.

1. Diagnostic Criteria for Schizophrenia: Clinical Implications and Challenges

main article: 1. Diagnostic Criteria for Schizophrenia: Clinical Implications and Challenges
author: Vikki T

“You take in information from all 5 senses properly, but you interpret it wrong. I thought communists sprayed gas under my apartment door at night and performed brain surgery on me while I was sleeping” - Former Air Canada Employee (Diagnosed with Schizophrenia)

Diagnostic and Statistical Manual of Mental Disorders
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The most recent edition of the Diagnostic and Statistical Manual
of Mental Disorders (DSM) was published in May 2013.
Source: Autism Consortium. 2013. Retrieved March 29, 2014, from:

Despite substantial research initiatives, the biological mechanisms and cellular processes that underlie the pathophysiology of schizophrenia remain elusive. As a result, the Diagnostic and Statistical Manual of Mental Disorders is the primary source of schizophrenia diagnoses in North America. Since it’s inception in 1952, the DSM has evolved through 5 subsequent versions to the DSM-5, the most current manual to date[1]. The aim of each revision is to progress towards an increasingly valid diagnostic manual that will aid in the development and application of successful treatment regimes[2]. The publication of DSM 5 in May 2013 has profound implications on the diagnoses and classification of schizophrenia. In prior editions, schizophrenia was diagnosed according to 5 subtypes: paranoid, disorganized, catatonic, residual and undifferentiated. Due to the heterogeneity between schizophrenia subtypes and inconsistent diagnostic practises, the DSM 5 has introduced the abolition of the subtypes that were previously used to characterize the disorder. Consistent with the notion of moving away from the subtype approach, the DSM 5 employs a dimensional approach that focuses instead on the severity of varying symptom clusters[3]. Although the incorporation of the DSM 5 into clinical practise has promising potential, its implementation into the clinical setting is not without challenge. These diagnostic adjustments may not be widely accepted by clinicians or they may have devastating effects on the prevalence of a given mental disorder in a population. As research on the etiology of schizophrenia continues, diagnostic practises aimed at earlier identification and intervention will emerge. The comprehensive result of this process is a continually improved diagnostic system that will better serve mental health professionals in the effective, accurate diagnosis of schizophrenia.

1. Tandon, R. et al. Definition and description of schizophrenia in the DSM-5. Schizophrenia Research. 150, 3-10 (2013).
2. Heckers, S. et al. Structure of the psychotic disorders classification in DSM-5. Schizophrenia Research. 150, 11-14 (2013).
3. Ritsner, M. et al. Symptom severity scale of the DSM5 for schizophrenia and other psychotic disorders: diagnostic validity and clinical feasibility. Psychiatry Research. 208, 1-8 (2013).

2. Causes of Schizophrenia

main article: 2. Causes of Schizophrenia
author: Svetlana Yunaev

Schizophrenia brain
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dopamine levels and cortical thickness of grey matter are both compromised in patients with Schizophrenia [3]

Schizophrenia falls under the category of psychotic syndromes and is known to be associated with the following symptoms: hallucinations and delusions, motivational impairment, depression, mania and cognitive impairment.[1] Schizophrenia is believed to be the outcome of a complex interaction between susceptibility genes and the environment. Individuals with a family history of schizophrenia are more likely to develop it than someone whose family is unaffected, which likely indicates a genetic component to schizophrenia. But those genes might not be expressed unless they are triggered by stress factors introduced by the individual’s environment.[1] Susceptibility genes that likely give rise to schizophrenia are those that impact prefrontal function including the COMT gene and NRG 1 gene.[2] Stress factors that can trigger schizophrenia in genetically predisposed people include cannabis abuse, an urban upbringing, developmental and prenatal trauma. [1]

1. Van Os et al. (2010). The Environment and Schizophrenia. Nature, 468, 203-212.
2. Sei Y, et al. (2010). Epistatic and functional interactions of Catechol-O-Methyltransferase (COMT) and AKT1 on Neuregulin1-ErbB signaling in cell models. PLoS ONE, 5, 1-14.
3. [Image 1. Frontal composite variability of normal and schizophrenia brains by gender]. Retrieved March 31st, 2014, from:

3.Treatments for Schizophrenia

main article: 3.Treatments for Schizophrenia
author: Michelle K Lee

Schizophrenic Neurons
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Treatment plans are individualized due to the complexity of each
patient's symptoms, which parallels the complexity of the neurons affected.
Source: Schizophrenic neurons. 2011. Retrieved March 30, 2014,

Schizophrenia is a chronic and debilitating mental disorder that manifests itself in characteristic ways that include: emotional dysregulation, interrupted thought processes, delusions and paranoia.[1] Due to the prevalence of this disease in modern society, schizophrenia treatments continue to be researched in order to elucidate further methods with higher efficacy. Current treatment cornerstones reveal themselves in the different categories of pharmacological treatments and Psychosocial treatments, each with various levels of efficacy targeting specific symptoms of schizophrenia.[2] There is no single treatment method considered effective for all patients. Each treatment plan must be tailored to the specific patient, though in the Western countries, pharmacological treatments are the most commonly used for both negative and positive symptoms of psychosis. However, many of these drugs also carry long-term side effects. Psychosocial treatments are effective in social cognitive improvements, and currently many treatments undergo experimental trials as new, innovative techniques continue to emerge in the process of finding an effective treatment regime.[3]

2. Kane, J.M., & Corell, C.U. Pharmacologic Treatment of Schizophrenia. Dialogues Clin Neurosci. 12, 345-357 (2010).
3. Bloch, Y. et. al. Normobaric Hyperoxia Treatment of Schizophrenia. J Clin Psychopharmacol. 32(4), 525-530 (2012).

4. Current Studies of Schizophrenia

main article: 4. Current Studies of Schizophrenia
author: Samuel Law

Current Studies of Schizophrenia
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Figure 1. An example of white matter fiber bundles mapped using diffusion tractography.
Each different color represents a separate fiber bundle

The nature of schizophrenia as a disorder is still not well understood today and remains controversial within the field of neuroscience and psychology. Without fully understanding the nature of schizophrenia, a proper, effective treatment is unfeasible. For that reason, research in schizophrenia has branched out into a multitude of directions in recent years with the assistance of technological and technical advancements. Advancement in technology such as neuroimaging and analysis techniques in genomics, etc. has provided us with much greater insight into schizophrenia than previously possible. A great example of technological advancement include diffusion tractography, which incorporates modern techniques of 3D modelling, diffusion MRI and image analysis to produce a 3D model of white-matter fiber bundles in the brain, allowing us to easily recognize structural deficits quickly[1]. Emerging analytical techniques such as Genome-Wide Association Studies (GWAS) allow for identification and association of symptoms and genes. With the emergence of these advancements, previous studies were strengthened or refuted based on new evidence, such as the neurochemistry and neurodevelopmental basis for schizophrenia, and current studies have branched out into completely new directions that were previously largely unexplored, such as neuroimmunology of schizophrenia[2], and new trends are still constantly emerging today.

1. Shenton, M. E., Whitford, T. J., Kubicki, M. (2010). Structural neuroimaging in schizophrenia from methods to insights to treatments. Dialogues in Clinical Neuroscience, 12(3): 317–332.
2. Müller, N. (2014). Immunology of Schizophrenia. Neuroimmunomodulation.21:109-116.
3. Fornito, A., Zalesky, A., Pantelis, C., & Bullmore, E. T. (2012). Schizophrenia, neuroimaging and connectomics. NeuroImage,62(4), 2296-2314. doi:

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