Support for this theory is the effect of amphetamines. These drugs work by increasing the levels of dopamine. When the drugs given to a non- schizophrenic the individual has been found to develop schizophrenic-like symptoms, this therefore suggests that the increased dopamine levels is likely to be linked to the disorder. Furthermore patients with schizophrenia have been found to have symptoms worsen when they have taken amphetamines. Grilly had found people with Parkinson’s disease (low levels of dopamine) who were taking the drug L-dopa to raise their levels of dopamine were developing schizophrenic type symptoms.
Alcohol/drugs can increase the level of dopamine (this compensates for the lack of dopamine receptors in individuals with A1 variant of the DRD2 gene). Dopamine stimulates the receptors and thud the behaviour is maintained and the individual relapses.
However, Clozapine is not 100% effective, suggesting that DA is not the only cause of SZ. Also, Clozapine treats both the positive and negative symptoms of SZ, with only the positive symptoms seeming to be related to excess DA levels, again suggesting DA is not the only cause of SZ. Seaman (1987) reviewed a number of studies involving post-mortems of SZ patients. He found that overall, SZ patients have an increase in DA receptor density of between 60% and 110% when compared to controls. However, it is not clear whether or not it was the excess DA which caused the patients to develop SZ, or whether it was having SZ that caused the excess DA.
Raleigh et al (1991) found that if serotonin levels were reduced by altering their diet, there was an increase in aggressive behaviour whereas an increase in serotonin levels resulted in a decrease in aggressive behaviour suggesting the difference in aggression was due to the serotonin levels. Other research demonstrating the link between low levels of serotonin and aggression was done by Bond (2005). He found that antidepressants which increase serotonin levels reduced irritability and impulsive aggression. The link between dopamine and aggressive behaviour is not as well established. However, increased levels of dopamine stimulated by amphetamines have shown an increase in aggression whereas antipsychotic drugs that reduce dopamine levels have been shown to reduce violent behaviour (Lavine and Buitelaar).
They revolutionised psychiatry by allowing the most disturbed schizophrenic patients live outside a psychiatric hospital, or reduce their average length of stay. However, many critics have called these drugs pharmacological straitjackets. Some drugs are more effective in treating acute positive symptoms such s hallucination, thought disorder and delusions; they seem to work by blocking the D2 receptor of dopamine. There are two main two main drug categories; neuroleptic drugs which are the more traditional used drugs and the newer version atypical drugs. Common neuroleptic drugs such as Thorzine aim to block the activity of the neurotransmitter dopamine within 48 hours, which have proven to be effective.
Brain scans can be used to help diagnose some disorders. Furthermore, the genes we are born with, from our parents, provide the blueprint for our bodies and brains. A slight abnormality in our genes can affect the functioning of our brains. Also to operate properly the brain relies on hundreds of chemicals to operate in the correct balance, these chemicals are used to send messages around the brain. Therefore if there are chemical imbalances abnormality may occur, for example low levels of serotonin are linked to depression and schizophrenia is linked with high levels of dopamine.
Macbeth is also hallucinating. Macbeth is eligible for the diagnosis of Schizophrenia, because he possesses at least two of the symptoms that a typical Schizophrenic would have. Also in order to be diagnosed with
Lead researcher Dr. Phillip Shaw said, "If you have a certain variant of this gene, you have a greatly increased risk of having ADHD." In the second study, scientists found that ADHD is associated with lowered dopamine production. ADHD is a real disease, which can not be cured but only treated. According to Journal of Child and Adolescent Psychopharmacrology, scientist recorded a study after conducting research on the long usage of IR-MPH, which they found children who took the 10 month trial of the medicine showed decreased signs of ADHD symptoms. Jeffrey Newcorn’s scholarly journal about Pychopharmacrologic Tretment recognizes methylphenidate and detroamphetamine as both good medicines to help control the symptoms of ADHD.
Schizophrenia & Other Psychotic Disorders: Schizophrenia, Delusional Disorder, brief Psychosis, Schizo-affective Disorder & Shared Psychotic Disorder. SchizophreniaSchizophrenia is a psychotic illness which can affect people in variety of ways, there is no evidence as yet why one develops the illness. Studies suggest there can be a combination of factors which can trigger the illness. It is agreed by health professionals that schizophrenia is most likely caused by a combination of factors, which can include the following: Dopamine is one of the chemicals that carry messages between brain cells and if there is too much Dopamine it can be a factor of one developing the illness. Genetic can play a big part in someone developing the illness as they are more vulnerable to the illness.
Schizophrenia is defined as a psychotic disorder in which people are disturbed by their own thoughts. Whether it be voices or illusions people that suffer from this illness tend to distort reality. Schizophrenia is usually diagnosed between the ages of 16-30, though it is still being researched today, we are not certain how schizophrenia is developed. Some scientists believe that schizophrenia is caused by a gene malfunction; other scientists say it is caused by family genetics. There are three main symptoms of schizophrenia, delusions, hallucinations, and thought disorder.