Dopamine, Schizophrenia, and...Creativity?

Of all the psychotic disorders, schizophrenia happens to be one of the most common. Within the American population, roughly 1.2% (or 3.2 million people) have it. It is also a relatively slow acting disorder. This type of psychotic break is classified by a mental separation from reality. The majority of people who have schizophrenia see symptoms arise during their late teenage years and early twenties. However, there are outliers that start to see symptoms during their forties and fifties. The main symptoms that are evident with this condition are hallucinations, abnormal behavior, and isolation. Based on these traits of the disorder it could be concluded that it has ties with neurotransmitters and the inner workings of the brain. There are two main groups that classify the symptoms of schizophrenia: positive and negative. The positive symptoms are normally repetitive actions that are challenging to control while the negative symptoms take away a function/feeling. Some examples of positive are: hallucinations, delusions, and racing thoughts. For negative the symptoms are: apathy, lack of emotion, and non-existing social functions. In addition to dopamine, glutamine plays a role in the development of Schizophrenia. Glutamine is an "excitatory neurotransmitter" in the brain, so it helps to active neurons and other brain cells. This means that the multiple brain areas that are involved in schizophrenia are connected by a circuit of brain cells that rely on glutamate to communicate. Surprisingly, the exact causes of schizophrenia are unknown but it's accepted that the disease results from an interplay of environmental factors and genetics. It has been commonly known to develop over time due to numerous things such as: drug use, trauma (emotional), brain changes, genetics, and pregnancy complications. The common assumption among researchers is that it is a combination of those causes.

The Symptoms observed of Schizophrenia
(Source)

As mentioned before, schizophrenia is connected with neurotransmitters. Dopamine happens to be one of those neurotransmitters that contribute to the symptoms seen in schizophrenia. Therefore, an overactive dopamine system could result in this disorder. This was proven through the medications that block dopamine receptors, specifically D2 receptors. When they block the receptors, the symptoms of schizophrenia subside. Essentially, the D2 receptors which reside in the thalamus and the striatum, have a change in binding potential as a result of the disorder. If schizophrenia is left untreated in patients, there is an increase in the amount of receptors in the striatum. To further delve into this topic, some authors came up with an experiment to test the D2 receptor density in people who are creative. Ultimately, the result was that more creative people had a lower D2 receptor density in their thalamus just like patients with schizophrenia. 

Dopamine Receptors in the synapse (Source)

Due to the less density of these receptors in this area of the brain, it was concluded that both creative and schizophrenic people have brains that don't filter out as much information as the average person does. This allows them to come up with a different train of thought compared to other people. For creative people, this means new and unique ideas while for people with schizophrenia it explains their abnormal thought process. (Articles on dopamine in relation to creativity: #1, #2, #3)

To put some of this into perspective, dopamine has been observed to have a hyperactive transmission in the prefrontal cortex of the brain of schizophrenia patients. This is generally the area where decisions are made, so if an overload of dopamine is within that area, it causes not only impaired judgement but also the execution of odd behaviors. Additionally, dopamine dysregulation has also been observed in the amygdala which is as essential for emotional processing as the prefrontal cortex. 

  

The affected brain areas by dopamine (Source) 

With the function of dopamine being well known among scientists, the overlap between it and neurological disorders are inevitable. Dopamine is known as the pleasure reward or the "feel good neurotransmitter." Therefore, it affects mood, motor function, and decision making. However, dopamine is reliant on the cycle of motivation, reward, and reinforcement, which makes it harmful in excess. If that normal cycle changes, dopamine will be released in overdrive and make you feel good... for a short amount of time. It is much like a "high" and the long term version of this would be schizophrenia, except the amount of dopamine is so much that the negative effects (such as hallucinating) are experienced but the reward feeling isn't.