There have been years of studies that try to pinpoint exactly what causes schizophrenia. Many different theories have been tested, but the dopamine hypothesis is one that has gained the most attention. This is most likely because it is the closest to explaining how symptoms that people with schizophrenia experience, such as hallucinations, come to be. So the question is what exactly is the dopamine hypothesis? In this article we will look at what the dopamine hypothesis is, and how it is linked with schizophrenia.
It’s important to first know what dopamine is:
“Dopamine is a neurotransmitter that helps control the brain’s reward and pleasure centers. Dopamine also helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them.”
Dopamine affects people with schizophrenia because it affects their abnormal thought process. This will result in psychotic symptoms such as hallucinations, delusions, disorganized behavior, and disorganized speech.
There have been many different variations of the dopamine hypothesis. The first stated that hyperactivity of dopamine was the cause of schizophrenia. This came to be after many clinical observations were made. The problem with this hypothesis is it only focused on specific parts of the brain and did not extend past that. As years went by more studies were done and an increased awareness of symptoms and how they affected a person with schizophrenia were shown. The most recent update of this hypothesis is that schizophrenia is caused by an overactive dopamine system.
Professor Jeffrey Lieberman explains it as:
“the symptoms of schizophrenia, principally the hallucinations, the delusions, the psychosis is the result of too much dopamine being active in the brain, being secreted into the synapses within a certain neural circuit. And as a result of this, it produces this over-stimulation of the cells and these symptoms.
In other words unusual behaviors that are portrayed by people with schizophrenia, according to the dopamine hypothesis, can be explained by the dopamine function in the brain. A person with schizophrenia’s brain usually produces more dopamine than a normal person.
There are many pieces of evidence that point to dopamine being a direct cause of schizophrenia. When tested, drugs that block dopamine have also removed schizophrenic symptoms. Best known medications that treat schizophrenic symptoms, block dopamine receptors. Therefore a conclusion can be made that if the medications main purpose is to block dopamine receptors than it is dopamine that is causing the schizophrenic symptoms.
Although this hypothesis makes sense, there are other factors that have to be looked at. Drugs that are meant to block dopamine receptors are fast acting and take place right away. This would mean that schizophrenic symptoms would also stop right away. This is not usually the case, symptoms can take many days to start to reduce. Another possible case for the dopamine hypothesis to not be true would be that these effects may be completely indirect. While they do block dopamine receptors they could also be stopping other symptoms that are having the actual effect on the schizophrenic symptoms.
The Dopamine Hypothesis has gained lots of traction and is widely believed to be the cause of schizophrenia. The main problem is that there is not enough proof for it and not enough proof against it. Researchers continue to look for the answer of whether the dopamine hypothesis is true or not.