genes | A01 Explanations/Research | Strengths | Weaknesses | | Family and Twin Studies:Evidence for the genetic basis of OCD comes from twin studies and evaluations of first degree relatives. Nastadt et al. (2000) identified 80 patients with OCD and 343 of their first degree relatives and compared them with 73 control patients without mental illness and 300 of their relatives. There was a strong familial link for the most common form of this disorder. People with a first degree relative with OCD (parents or siblings) had a five times greater risk of having the illness themselves at some time in their lives compared with the general population.A meta-analysis of 14 twin studies of OCD, including 80 identical and 29 fraternal twin pairs,
There could be some damage to the central nervous system but not very severe or the symptoms that Nick exhibits would be more severe. C. Diabetic neuropathies damage peripheral nerves. Which component of the reflex arc is most likely to be damaged in Nick’s situation? The component of the reflex arc that is most likely to be damaged in Nick’s situation would begin at the sensory neuron. Stimuli is still triggering the receptor but the information from the sensory neuron doesn’t continue the arc to the integrating centers to the motor neurons to the effectors which causes the absence of a reflex.
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.
For a person to have controlled voluntary muscle movement, then the combination of dopamine and acetylcholine is necessary. When there are imbalances in the level of neurotransmitters, it will cause harmful effects to the person who has the imbalance. An imbalance in neurotransmitters can cause both physiological and mental illness. For example, if a person does not have enough dopamine, then it appears to cause the person to have the symptoms of Parkinson’s disease. Parkinson’s disease causes a person to have involuntary muscle
Essay Plan Biological Explanations of Schizophrenia 1. Describe in some detail the genetic factors- family studies- Gottesman found that schizophrenia is more common among biological relatives of a person with schizophrenia and also that the closer the degree of genetic relatedness, the greater the risk. For instance, children with 2 schizophrenic parents have a concordance rate of 46%, children of one schizophrenic parent 13% and siblings 9%. Although this could be due to common rearing patterns or other factors not relating to heredity. Twin studies- Joseph calculated concordance rates of 40.4% for MZ twins and 7.4% for DZ twins.
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.
Answer the following questions. 1. What could have caused Myelin’s disease? Well, they may be driving at Multiple Sclerosis, for a bonus point, this is more prevalent at high lattitudes and there is a possible negative correlation with vitamin D levels. Other causative factors include lack of EFAs, whereby the body strips EFAs away from the myelin sheath of peripheral nerves to preserve the levels in the brain itself.
Anti depressants such as MAOI’s which increase the available amount of nor adrenaline in the brain, were found to be effective for elevating the symptoms of depression. So when noradrenalin is increased in the brain, symptoms of depression get better, suggests that it is chemicals that are the root cause of depression. This idea is also found in the results of taking reserpine, a drug used to treat high blood pressure. Depression is a unwanted side effect of this drug, as this drug acts by lowering levels of nor adrenaline. So again strongly suggests that low activity noradrenaline, is a factor contributing to the cause of depression.
A family study conducted by Gottesman reported that the rate of schizophrenia in the general population is 1% whereas the rate in people where both parents suffer in 46%. He also found that if one parent suffered the rate was 13%. Gottesman concluded that the closer the bloodline the higher the risk. He and Shields then conducted a study on the concordance rates of schizophrenia in 40 sets of twins. They found that in dizygotic twins the rate
The neurotransmitter I believe would have abnormal function after a stroke is Acetylcholine. Acetylcholine is a common neurotransmitter used in the spinal cord and motor neurons to stimulate muscle contractions. It’s also used in the brain to regulate memory, sleeping, and dreaming. Acetylcholine is the primary chemical carrier of thinking and memory. Since a stroke can affect your memory and walking ability I believe acetylcholine would be abnormal.