Реферат: Brain Chemistry Essay Research Paper Brain Chemistry
Antipsychotic drugs primarily have a selective effect on dopamine cell firing, that is, they affect only those dopamine neurons which go to the limbic and frontal cortex but not the dopamine neurons that effect motor control. Some antipsychotic drugs also effect serotonin, noradrenaline, and histamine receptors. They are used in the treatment of schizophrenia, borderline personality, psychosis, delusions, hallucinations, and paranoid personality. The antipsychotic drugs include lithium, haldol, clozapine, and newer drugs such as risperidone, olanzapine, serditindole and, now in the trial phase of development is ziprazidone. The main side effect of these drugs is that they effect motor control but they also may have cardiac effect and induce seizures. The newer drugs offer fewer side effect than the traditional drugs (Tamminga).
Schizophrenia is a mental illness that affects one percent of the population. It is a degenerative disease. Symptoms usually begin in adolescence or early adulthood. The symptoms are psychotic episodes, hallucinations, delusions, and bizarre behavior characterized by lack of initiative, emotional unresponsiveness, social withdrawal, and strange speech patterns. Neurologists believe that schizophrenia might involve a defect in the connections between the temporal lobe of the cerebral cortex and dopamine producing neurons near the base of the brain. Studies have shown fewer neurons in these regions. They also believe that it may involve a defect in the neurotransmitter gamma-amino-butyric acid (GABA) which acts as an inhibitor. Schizophrenics show unusually low brain levels of GABA. Antipsychotic drugs have helped in the treatment of schizophrenia but they are still far from ideal. Twenty to thirty percent of patients with the disease do not respond to medications. Even some patients who initially respond well to drug treatment have only short term results and ultimately deteriorate in overall function (Benes).
Addiction comes in many forms. People can be addicted to alcohol, marijuana, cocaine, heroin, cigarettes and many other chemicals. There has been overwhelming evidence linking addiction and the brain chemical dopamine. Brain imaging technology has been used to track the rise of dopamine and link it to feelings of euphoria. Drugs can be thought of as sledgehammers in that they profoundly alter many pathways. Dopamine seems to be a common endpoint to all those pathways. Nicotine, heroin, alcohol, and cocaine raise dopamine levels. A genetic trait that produces too little dopamine may be a key factor in who gets addicted. This research is going a long way toward helping in the recognition that addiction is a biological disorder. The more science understands the biology of addiction, the better treatments will become. A number of MAO inhibitor drugs are being used to help people stop smoking. Cocaine withdrawal cravings have been helped by a drug that targets the dopamine receptor known as d1. Methodone, which activates d1, is used in treating heroin addiction. These drugs help tide people over the first few months of withdrawal and help curb cravings. Drugs alone will not solve the addiction problems. The most important message that seems to be coming from recent research is that the biological disorders associated with addiction can be reversed through learning and drug treatments (Nash).
Depression research suggests that it is related to deficiencies in dopamine, norepinephrine, and serotonin neurotransmitters. Symptoms of depression include an overwhelming sense of sadness, helplessness, inferiority, despair, worthlessness, crying, guilt, loss of energy, sleeping too much, loss of concentration, and thoughts of suicide. Depression is one of the more difficult disorders to treat because of the multitude of symptoms and episode frequency. Many treatments are available and usually include trial and error to see what works best. Treatments include antidepressant drugs used to increase concentrations of deficient neurotransmitters, sometimes in combination with antipsychotic drugs, and also electroconvulsive shock therapy (Messer).
There have been many advances in brain chemistry research during recent years. Understanding how the brain works has led to the identification of neurotransmitters and what their functions are. Understanding how genes affect brain chemistry and our behavior has helped us identify particular genes and their function leading us to treatments of specific disorders. Drugs are now available that target specific neurotransmitters and functions in the brain with fewer side effects. Treatment of mental illness is now more successful than at any other time in history due to advances in our understanding brain chemistry and how it works. The future looks promising as research in brain chemistry continues and the advancement of knowledge provides more insight as to what makes us who we are.
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