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.
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. There is a flaw with one of the key pieces of evidence to support the dopamine hypothesis. The drugs used to treat schizophrenia by blocking the dopamine receptors can actually increases it as neurons struggle to compensate for the sudden deficiency. Haracz, in a review of post-mortem studies of schizophrenics, found that most of those studied who showed elevated dopamine levels had received antipsychotic drugs shortly before death, unlike post-mortem of schizophrenics who hadn’t received medication these results showed that these individuals had normal levels of dopamine. Therefore, this evidence then in fact weakens the support for the dopamine hypothesis.
Other psychiatric problems such as depression, Alzheimer’s, and dementia are not based on lab test either. Almost all of today’s known mental disorders would be eliminated and go untreated if we recognized diseases based solely on test done in a lab. However, recent studies think that have found the cause of ADHD. According to Health and Daily News “Attention-deficit hyperactivity disorder (ADHD) is a real disease linked to changes in production of the brain chemical dopamine, two new reports suggest.” In the first report researchers found that a variation in the dopamine receptor gene may help cause the behavioral condition of ADHD. Lead researcher Dr. Phillip Shaw said, "If you have a certain variant of this gene, you have a greatly increased risk of having ADHD."
Antidepressants on the other hand by balancing neurotransmitters such as serotonin and epinephrine witch can cause depression if not sufficiently balanced. Anxiolytic drugs are used to combat anxiety disorders one drug in this field is benzodiazepines (Bzs) they work by releasing more (GABA) witch slows down the nerve transmission calming people down. This drug is effective in areas such as phobias. Another biological therapy is ECT, it is a surgical based treatment commonly used on manic depressives who haven’t responded to antidepressants. This treatment is administrated to a patient by putting a patient into an unconscious state then passing a current of 0.6 amps through the brain.
In general, a brain affected by Dementia produces less of some neurotransmitter. which sets off an imbalance in the brain. For Example, In Alzheimer's, Too little Dopamine effects the acetylcholine levels in the body and starts to block receptors , disabling the brain to reach the right signal to the intended brain cell. Amino Acids, Monoamines, Trace amines, Peptides and Gasotransmitters are some of the endogenous chemicals who’s function it is to allow the transmission of signals from one neuron to the next neuron across the synaptic Cleft. Only 100 chemical messengers have been found to date.
Beck et al (1961) looked at inter-rater reliability between 2 psychiatrists who both looked at the same 154 patients, and found that the inter-rater reliability was low at 54%, meaning that the two systems may produce different results when it comes to the classification of schizophrenia. We could improve inter-rater reliability, and therefore the consistency of the diagnoses of schizophrenia by narrowing the classification systems down to one. Content validity refers to the extent to which the assessment measure covers the range of symptoms of schizophrenia, and so the classification systems have content validity if they provide complete coverage of all the possible symptoms. Jakobsen et al (2005) used OPCRIT, which is a clear and detailed list of symptoms to study patients with a history of psychosis. Unlike ICD-10, there was a good agreement on the diagnosis when OPCRIT was used, indicating a high level of reliability, and a high level of content validity.
With the reliability affecting schizophrenia Davison and Neale (1994) reviewed the inter-rater reliability of diagnosing schizophrenia from the mid-1960s onwards and found that with schizophrenia, there was a 0.81 agreement amongst clinicians (i.e. 81%). This showed that there is some general agreement over the diagnosis of this deliberating condition, however more recent studies have found the complete opposite of this such as Whaley (2001) who found inter-rater reliability correlations in the diagnosis of schizophrenia was as low as 0.11. In evaluation these differences with the inter-rater reliability are quite surprising, an implication from the above
Many researchers, such as Crow (1985) believe there are two different types of SZ with different underlying pathology. Type 1 SZ is the type of SZ which would be associated with the Dopamine Hypothesis; it involves DA dysfunction, is characterised by positive symptoms and responds well to anti-psychotic medication. Type 2 SZ, however, is the type that is unsupportive of the Dopamine Hypothesis- it is a neurodevelopmental disorder arising from prenatal insults or perinatal insults, characterised by negative symptoms and does not respond well to antipsychotic drugs. The idea of different types of SZ suggests that DA is not the only
“It occurs in 10 percent of people who have a first-degree relative with the disorder, such as a parent, brother, or sister. People who have second-degree relatives (aunts, uncles, grandparents, or cousins) with the disease also develop schizophrenia more often than the general population” (Schizophrenia, 2009). There isn’t just one gene that is associated with schizophrenia, but scientists believe there are several genes that are linked to the disorder. “Other recent studies suggest that schizophrenia may result in part when a certain gene that is key to making important brain chemicals malfunctions. This problem may affect the part of the brain involved in developing higher functioning skills” (Schizophrenia, 2009).
(Catherine Harrison, PhD, January 10, 2008) B. Drugs that remedy or lessen effects Antipsychotic and atypical antipsychotic drugs are used to treat this disorder such as: Risperidone and Clozapine among others. C. How these drugs help These medications cannot “cure” the illness, but they can take away many of the symptoms or make them milder. In some cases, they can shorten the course of an episode of the illness as well. These medications affect neurotransmitters that allow communication between nerve cells.