Schizophrenia is a dynamic and complex disorder with a wide spectrum of symptoms. The easiest way to study a complex disorder like schizophrenia is to attempt to find the basic processes that constitute the symptoms and behaviors associated with it. After finding the general biologcal processes that lead to expression of the disorder, attempts can be made to pinpoint a certain gene or genes speculated to be the direct cause. Researchers in the field of psychotic brain disorders already have an understanding that schizophrenia may be caused largely to genetic factors, this information coming from the high risk attached to individuals with a family history of schizophrenia. However, there is also evidence that environment affects the onset of the disorder, which leads to the necessity of defining the threshold at which environmental factors become predictors of the development and expression of schizophrenia.
The main schizophrenia research designs used to study the causes of schizophrenia are monozygotic twin studies, fraternal twin studies, and adoption studies.
Monozygotic Twin Studies: This type of study allows researchers to look at individuals who share 100% of their genes as well as their environment. Although no individual can have 100% of the physical, emotional, and social experiences as someone else, this type of study allows researchers to discover other variables that may be involved in the development and expression of this chronic degenerative brain disorder.
Fraternal Twin Studies: This type of study allows researchers to look at individuals who share 50% of their genes and 100% of their environment. Fraternal twin studies allow researchers to look at genetic influence on the development of schizophrenia.
Adoption Studies: This type of study allows researchers to investigate different levels of gene-sharing as well as the effect of growing up with a pre-disposition for the disorder in a household removed from the influences of a schizophrenic environment.
Family Studies: Although it is already known that the general population has approximately a 1% chance of developing schizophrenia, those who have a relative with the disorder are at a higher risk. If the relative is not a monozygotic or fraternal twin, or the mother or father, the individual has at least a 5% pre-disposed chance of developing schizophrenia. This type of study also allows researchers to look specifically at the spectrum of symptoms exhiited in schizophrenic patients.
The Main Types of Schizophrenia Research
Let’s take a look at the most common types of research involved in investigating this illness and the results they seem to be communicating to us.
Monozygotic Twin Study Findings
Monozygotic twin studies have revealed the importance of personal experience and its role in the development and expression of psychotic disorders. Studies about schizophrenia using this research design have revealed that although genes can make an individual vulnerable to schizophrenia, personal experience is significant for triggering the onset of the disorder as well as determining the severity of symptoms. This type of study reveals that even if environment is as similar as possible, individuals experience things in different ways, therefore affecting their resistance to certain mental illnesses.
Fraternal Twin Study Findings
Fraternal twin studies have also revealed the significance of gene sharing as a predictor of psychosis. Although sharing only 50% of genes as compared to monozygotic twins’ 100%, fraternal twins are still at a significantly higher risk of developing the disorder if the other twin is diagnosed. Studies have also concluded that fraternal twins have a higher likelihood of developing schizophrenia than other family members with less genetic ties.
Adoption Study Findings
Genes are a fascinating, especially when it comes to neurological makeup and the expression of complex psychotic disorders. Various studies using adopted children of schizophrenic parents or relatives have impacted the nature versus nurture theory tremendously. In the case of adoption studies, researchers are looking at environment alone as a deciding factor in expression of schizophrenia. In many cases, researchers found that although completely removed from a ‘schizophrenic environment’ children with some famly history of schizophrenia still had a high likelihood of developing the disorder. In some cases the probability was up to 22% if the mother of the adopted child had developed active schizophrenia.
Family Study Results
Family studies, while not very useful in contrasting nature versus nurture and its affect on the development of schizophrenia, is useful for studying the wide array of symptoms associated with the disorder. This type of research has found that although the disorder itself is heritable, the symptoms expressed in each family member may be completely different, shedding light on the idea that the biological cause of schizophrenia includes an immense coding system for a variety of symptoms and symptom combinations. These studies also reveal that there are ties between a family history of schizophrenia and development of general types of psychological disorders, not necessarily diagnosed as schizophrenia.
Dopamine studies focus on the theory that schizophrenia may be caused by an excess of the neurotransmitter dopamine. Studies into antipsychotic medications have revealed that dopamine-blocking neuroleptics or antagonists are effective in treating positive symptoms of psychology while agonists, used to treat other disorders such as Parkinson’s disease have produced schizophrenia-like symptoms. This leads researchers to conclude that if not entirely responsible for causing the disorder, high dopamine levels are corelationally significant concerning specific symptoms of schizophrenia such as delusions and hallucinations. Also relevant to the studies is the fact that low dopamine levels are associated with depression-like symptoms, also indicative of negative schizophrenic symptoms. The dopamine theory, although valid, needs further analysis as it has also been shown that not all schizophrenics benefit from dopamine-blocking neuroleptics, which further attests to the complexity of this disorder.
Other Schizophrenia Research Types
Although the technical details of each of the following types of research is out of the scope of this article, one should take the time also learn about genome-wide clinical microarray testing, chromosomal lesion location detection, environmental chronic lead exposure testing, and other lesser-known but equally important forms of schizophrenia research.
In the field of psychology and psychiatry, schizophrenia is still a research rich area as the exact cause of the disorder is not yet known. Schizophrenia can be compared to Autism as far as research opportunities are concerned as both disorders are highly invasive, extremely complex, and not yet treatable to a satisfactory level.