So again strongly suggests that low activity noradrenaline, is a factor contributing to the cause of depression. Support for this explanation has also come from research studies. Findings from psychologists , have led to the idea that depression is caused by a depletion of these naimes , especially serotonin and noradrenaline (in which I have discussed), however this idea is too simplistic, when infact its more complex than that. A example of why it is more complex is from the original theory, is that anti depressants do
People who think they have taken a drug but really haven’t may display the effects of the drug because they expect to be affected by it. The learned expectations regarding a drugs effect vary from culture to culture. 13.Depressant: reduce the central nervous system activity. Many depressants increase GABA neurotransmitter activity. Effect of alcohol: Alcohol has an impact on the dopamine, serotonin, endorphins, glutamate, and GABA neurotransmitters.
Researchers suspect that the caudate nuclei form perform this selection function poorly with those with OCD. As suggested by the high level f frontal lobe activity revealed in PET scans, obsessional thinking then persists, often until a compulsive ritual puts an end to it. | One strength of the brain dysfunction theory comes from further empirical support provided by Comer (1998) who suggests that because serotonin plays a key role in the OFC and caudate nuclei, it is likely that low levels of serotonin cause these areas to function poorly. This suggests that there is wider academic credibility for a causal effect between serotonin and regions of the brain. A second strength of the brain dysfunction theory is that it has
This suggest that depression must be passed on through genes if there is a high concordance rate between twins which share the same genetic makeup both having depression. However, biological factors such as the amine hypothesis states that if amines such as serotonin and noradrenalin become unbalanced, they can lead to depression. PET scans support this idea as they show that low levels of serotonin are present in people that are depressed. Other supporting evidence is that drugs such as MAOI’s, which work by increasing the available amount of noradrenalin in the brain, were found to be effective in alleviating the symptoms of depression. A problem with this is that it doesn’t state whether it is cause or effect.
The fact that both twins wouldn’t always develop schizophrenia means that another factor must be involved, for example family environment. Too much or too little of a particular neurotransmitter may produce psychological disorders. For example, an increased level of dopamine is linked to schizophrenia, and drugs like cocaine, which increase dopamine levels, can lead to schizophrenia like problems. Also, depression can be effectively managed and often treated with drugs that manage serotonin levels in the brain. However, Watson et al found that low serotonin levels may in fact be due to environmental factors.
Critical Point 3: 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 weakens the support for the dopamine
In terms of biochemistry, chemical imbalances in the brain may be involved in certain mental illnesses. Neurotransmitters, for example, play a very important part in behaviour – one theory links depression to low levels of the neurotransmitters serotonin and noradrenaline. However, the relationship between neurotransmitters and depression is very complex and therefore, more research is needed to discover the exact link between this and the disorder. People suffering from depression, also often have high levels of the hormone cortisol. Cortisol is sometimes referred to as a ‘stress hormone’ because it is produced in times of stress.
Research has been done by Silverstein et al in which it was found that biological factors may influence a person’s first positive or negative experience with their first cigarette. For example whether they feel nausea, or choke. Although this does not explain why a person initially picks up a cigarette it does give us an explanation for why some people continue the initiation of smoking. Those with worse experiences due to the biological factors may be less likely to continue to start smoking. Hall et al also suggests that nicotine addiction is likely to involve multiple forms of genes that each have a small effect that interacts with each other and environmental factors.
Date: march 21st,2012 The press releases make casual claims from data that is only correlation, for example, they make a claim that nicotine boosts levels of cortisol which is a stress hormone. The press also claims that increased level of cortisol can result into weird hallucinations. However, this is a complete misrepresentation of what the Durham University researchers found. The researches found that cortisol role is to translate the experience of the experience of psycho-social stressors to psychosis. The misconception is that caffeine directly leads to increase in stress levels because cortisol is involved.
Another big theoretical view is the dopamine theory much research has been done on the neurotransmitter dopamine. According to the dopamine theory, people with schizophrenia use an abundance of dopamine, although they may not make more of it. Researchers suggest that people with schizophrenia have a large concentration of dopamine at the synapses in the brain, this maybe linked to the confusion that characterizes people with schizophrenia. Treatment for schizophrenic symptoms varies from patient to patient depending on how bad a persons schizophrenic symptom are, but the normal for people with mild schizophrenia is counseling and therapy plus medications that help control the symptoms. Some other forms of treatment is rehab, and family therapy also other people suffering from the same disorder also sometimes hospitalization is required to make sure that the medication works and the symptoms will go away.