Mental Health Illnesses Have A Genetic Contribution

For major depression between monozygotic and dizygotic twins suggest a heritability of about 37%. It is lower than the heritability of bipolar disorder or schizophrenias.

Researchers also believe that genes are one of the causes of schizophrenia, however they are convinced that genes alone can’t be the main cause, they just make a person more likely to develop the mental disease. (Nimh.nih.gov,

As defined by experts, a mental illness is a clinically significant behavioral or psychological syndrome or pattern that occurs in an individual and involves changes in thinking, emotion, behavior, interpersonal interactions, daily functioning, or a combination. The causes of mental illness are complex and vary depending on the theories associated to the different biological, psychological, and environmental factors. The etiology of mental illness is based on five broad models: biological, psychological, behavioral, cognitive, and social.

Schizophrenia is a brain disorder revolves the way a person would think, act and the way they would see the world. They usually have a different view of the truth and this is frequently loss of contact with what going on. People that have the disorder could hear or see things that don’t exist and even speak strange, believe that others are trying to harm them, or sense they’re being watched. The biological explanation for schizophrenia, through biological faults, for instance viral infections and brain abnormalities Genetic Factors Certain psychologists predict schizophrenia can be passed down generations however this implies some people inherit the disorder from their parents. Identical twins have a higher risk of schizophrenia, meaning one of the twins can have the disorder and is a greater chance is they’re identical rather than non-identical. During my research I found that ‘Gottesman’ (1991) reviewed 40 studies and established ‘monozygotic twins have a concordance rate of 48%’, whereas dizygotic twins have a concordance rate of 17%. This demonstrates the correlation between genetics and the risk of developing schizophrenia. However if there was no genetic element there would be no difference of risk from first relatives. Yet there is 1% possibility of someone at random picked. Adopted studies is way more real way of splitting out the effects of environmental and genetic factors- adopted children later progress schizophrenia and care

The biological explanation of schizophrenia also claims that the disorder can be inherited. The more common the disorder is among the biological relatives and the closer the degree of genetic relatedness increases the risk of the child developing schizophrenia. Gottesman’s research (1991) found a genetic link with schizophrenia when looking at children and their relatives. The research discovered that children with two schizophrenic parents have a concordance rate of 46% compared to children who just have one schizophrenic parent to children who have a concordance rate of 13% and siblings just 9%. The genetic theory of schizophrenia also suggests that monozygotic twins (twins who a genetically identical) should have a higher concordance rate of schizophrenia than dizygotic twins (twins who are not genetically identical) because they have a closer degree of genetic relatedness.

In support of this Kendler et al found that first degree relatives of those with schizophrenia are at 18 times more risk than the general population. Research has also found that schizophrenia symptoms may have a genetic component. This was suggested by Malaspina, who found that patients who have schizophrenia in their family histories are more likely to develop negative symptoms than those families who are schizophrenia free. In evaluation of family studies it may be concluded that they are not very reliable as they are retrospective. The studies for family studies where taken place when diagnosis was under a more liberal use of the term schizophrenia. Twin studies have also shown a genetic pre-disposition. Gottesman found 48% risk of schizophrenia in MZ twins compared to only 17% in DZ twins. Similar to the Gottesman study two other studies showed higher concordance rates for MZ twins and lower in DZ twins however each had slightly different results. McGuffin et al argues this is because of the use of different diagnostic criteria, which may affect the validity of the results. On the other hand the researchers used blind techniques to obtain the results eliminating any researcher bias.

It is believed that faulty genes can cause some disorders that have a psychological effect. A way in which this can be tested is by doing studies on twins as they have the similar genetics. McGuffin et al did a study in 1996 where they compared 109 sets of twins in order to investigate how likely each twin was to develop depression. They looked at the concordance rates for depression in MZ and DZ twins, they expected that MZ twins either both have depression or neither have depression. So therefore its expected to find a higher concordance for depression in MZ twins that in DZ twins. The results showed that if one non identical twin developed depression that there was a 20% likelihood that the other would too, in identical twins this rose to 46%. This study therefore proves that genetics can have a massive impact on abnormality.

Genetic factors of schizophrenia can be explained using studies on twins and studies on family history. With twin studies researchers want to establish the degree of concordance. This is

The general public increasingly attributes mental disorders to biological causes such as a chemical imbalance or inherited genes (Schnittker, 2008; Schomerus et al., 2012).

Aside from genetic studies, it has previously been noted that there are associations between some of the personality traits (which are quantitative in nature and applicable to all human beings) and some categorical psychiatric conditions like depression and schizophrenia [Koorevaar et al., 2013; Guerra et al., 2000]. Identification of the genetic components of personality traits, at the same time as studies are underway to identify genetic components of bipolar disorder and other psychiatric conditions, offer an opportunity to better understand the interactions and components of the biological components that shape psychological experience and psychiatric illness.

According to the Mayo Clinic, “Schizophrenia is a severe brain disorder in which people interpret reality abnormally. Schizophrenia may result in some combination of hallucinations, delusions, and extremely disordered thinking and behavior.” The mental illness can cause people to act against their will, and will cause great harm to the victim of such illness. According to the NIMH, “Genetic tests for some rare diseases clearly tied to a specific, single gene, like cystic fibrosis, fragile X syndrome (a heritable cause of mental retardation), or sickle cell disease, give people definitive answers about their risk of getting these rare illnesses.” The two sources show us that genetic testing can tell someone whether they have the risk of late

This can also be accounted for distant relatives who are unlikely to share the same environment. We can therefore assume that to confirm a genetic base for schizophrenia, research must separate genetic influences from environmental influences. In order to do this, researchers must look at the evidence presented through twin studies. A set of MZ twins share the same genes, therefore if only one of the develops schizophrenia, it is more likely to be through environmental factors.

2. A strong family history of mental disorders is considered as a highly probable cause of schizophrenia, while those who are much less genetically vulnerable are believed to catch the disorder through environment stressors during their lives.

1978 shields discussed 11 studies of the identical and non-identical co-twins of over 1300 schizophrenics from seven countries and then of these comparisons showed a higher concordance rate among identical twins. (A, C, Smith 1982 p.g 93) Research is still going on today to find out more about how genes and life events influence who gets schizophrenia.

Conclusions / Results: Conclusions suggest that the nature vs nurture dichotomy may not be as relevant as looking at the interaction between these two forces. It was discovered that while one’s genetic heritage creates a predisposition towards schizophrenia, other factors such as the home environment, the parental environment, dietary factors and others may determine whether the disease is manifested.