Discussion Board 13
For this discussion, describe the ‘dopamine hypothesis of schizophrenia’. What are the relevant updates to this theory? Please cite a scholarly article that was published in the previous five years.
The following article might help as a starting point as you consider this discussion:
Howes, O.D., & Kapur, S. (2009). The dopamine hypothesis of schizophrenia: Version III – The final common pathway. Schizophrenia Bulletin, 35(3), 549-562. doi: 10.1093/schbul/sbp006
Dopamine is a neurotransmitter. The body creates dopamine and the nervous system uses this neurotransmitter to send messages between nerve cells. This is the reason why it can often be called a neurotransmitter. Dopamine is often also called the pleasure transmitter. With dopamine, people are able to better concentrate and find things interesting. Having too much or not enough dopamine can often lead to multiple health complications.
Dopamine plays a major role in mental health. It can be the cause of mental health disorders or challenges. For example, ADHD research has shown that there may be a shortage of dopamine. Schizophrenia has been a mental health disorder linked to too much dopamine for decades. Researchers believe that this hyperactive dopamine system is responsible for hallucinations and delusions that are positive symptoms of schizophrenia. Lack of motivation, a negative symptom of schizophrenia can be caused by a lack of dopamine. This hypothesis that dopamine is to blame for schizophrenia has made scientists look further into their research.
Stephan Stahl (2018) believes that the dopamine hypothesis can now include serotonin and glutamate. This is because although a hyperactive dopamine system is linked to psychosis, it is not the only neurotransmitter that is linked to psychosis. In psychosis, there are three hypotheses. The dopamine theory, as explained, shows hyperactive dopamine in the mesolimbic pathway. The NMDA theory says that the NMDA receptor is malfunctioning. Lastly, the serotonin theory shows that the 5-HT2A receptor is hyperfunctioning in the cortex.
Scientists observed how each of these neurotransmitters functioned by the use of drugs and which drugs connected to specific neurotransmitters cause which affects to the human body. They’ve discovered that when it comes to psychosis, schizophrenic patients have a different type of hallucinations than those who have dementia. This is possibly because those with dementia don’t seem to have as much dopamine production as those with schizophrenia. Scientists are now looking at the possibility of serotonin having more of an effect on the psychosis of people with dementia causing the psychosis to be different.
Stahl, S. (2018). Beyond the dopamine hypothesis of schizophrenia to three neural networks of psychosis: Dopamine, serotonin, and glutamate. CNS Spectrums, 23(3), 187-191. doi:10.1017/S1092852918001013