Outline and evaluate biological explanations of schizophrenia Genetic evidence for explaining the causes of schizophrenia usually are either family studies, twin studies or adoption studies all of which rely upon correlation. First degree relatives share an average of 50% of their genes and research has shown the closer the biological relationship, the greater the likelihood that someone has of developing schizophrenia if the relative in question has schizophrenia. Twin studies have compared the difference in concordance rates of schizophrenia between dizygotic and monozygotic twins when both share similar environments. Most show a higher concordance rate in monozygotic twins illustrating the genetic link involved in predisposing individuals to the condition. Adoption studies go one step further in narrowing down a strong correlational link by ruling out the effect of environment on development of schizophrenia to illustrate the genetic link more clearly.
Twin studies by Kendler in 198 reported a concordance rate of 50% of monozygotic and 15-16% of dizygotic twins. This evidence is closely related to that of Gottesman, which displays clear links between identical twins, compared to non-identical. Adoption studies carried out by Heston in 1966 studied 47 children whose biological mother has schizophrenia and who had been placed in adoptive or foster homes less than one month after birth. He then compared them to 50 controlled offspring and the environments for both groups were similar. It was concluded that 5 of the children with mothers with schizophrenia were diagnosed with the disease compared to none of the controls.
This problem may affect the part of the brain involved in developing higher functioning skills” (Schizophrenia, 2009). The age of diagnoses for men is in the mid 20’s and women in their late 20’s. “Many environmental factors may be involved, such as exposure to viruses or malnutrition before birth, problems during birth, and other not yet known psychosocial factors” (Schizophrenia, 2009). Environmental factors include prenatal stressors, drug use and living environment. Living in urban areas as a child or as an adult significantly increases the risk of developing schizophrenia.
The risk is highest for an identical twin of a person with schizophrenia. He or she has a 40 to 65 percent chance of developing the disorder (U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, 2009). It’s been proven that schizophrenia does run in families. However, the fact that there are multiple causes for schizophrenia including outside factors such as environmental causes proves the point further that no test screening is ever completely and entirely accurate. For example, just because a person gets the screening, and it comes back negative, doesn’t mean they may not develop schizophrenia later on in life.
Genetics Factor Behind Childhood Schizophrenia This research paper examines the role of genetic and environmental risk factors in the development of childhood schizophrenia. Childhood schizophrenia appears to be a disorder of development that results from a series of neurological insults from fetal life onward. Whether or not schizophrenia manifests in the result of a conglomeration of these factors, both genetic and environmental. Schizophrenia undoubtedly has a genetic component. The risk of inheriting schizophrenia ranges from about 10% for those who have one first-degree family member (mother, father, sister, brother) with the disease to about 40%-65% if the disease affects both parents and an identical twin.
Gottesman (1991) investigated twin studies of monozygotic and dizygotic twins. He summarized 40 concordance studies and found that when one of the twins was diagnosed with schizophrenia, monozygotic twins showed a 48% concordance rate over a 17% concordance rate in dizygotic twins. Due to the monozygotic twins sharing 100% of their DNA and dizygotic sharing only 50%, this shows that genetics are very likely to play a role in someone developing schizophrenia. However, due to concordance rates not being 100% in MZ twins, it also suggests that some environmental factors must play a role too. Loehlin and Nichols (1976) suggested that the high concordance rates in MZ twins is most likely to be due to the fact they will be treated very
The manuals are frequently revised and it has recently been updated to DSM V. There are five different types of schizophrenia; paranoid, disorganised, catatonic, residual and undifferentiated. The paranoid type believe people are plotting against them, are anxious, suffer from delusions, are suspicious of people and they respond to medication. The disorganised type is the silly mind and they suffer from the ‘flat effect’ which is a monotone voice and disorganised speech and behaviour. The catatonic type is when a person has problems with their motor movements; either uncontrollable motor movement or being stood like a statue and mute. The residual type is a milder form of schizophrenia and symptoms are reduced in number and intensity.
It is clear that postnatal maternal depression can impair maternal care and may be associated with delayed social, behavioral, cognitive, and physical development in growing children. There also is evidence that adolescent children of depressed fathers are likelier to experience psychopathology. This longitudinal cohort study, the Avon Longitudinal Study of Parents and Children (ALSPAC), postulated that paternal depression postnatally would be associated with a heightened risk of behavioral and emotional problems at age 3.5 years. Participants included 13,351 mothers and 12,884 fathers, all of them evaluated 8 weeks postnatally using the Edinburgh Postnatal Depression Scale (EPDS). The fathers were again assessed when their children were 21 months old.
[pic] Schizophrenia, severe mental disorder characterised by a profound disruption of cognition and emotion, which affects a person’s language, thought, perception, affect and even sense of self. In most countries across the world, the lifetime risk of being diagnosed with schizophrenia is 1 per cent. There is a distinction between acute and chronic onset schizophrenia. In chronic onset, there is often an insidious change in an apparently normal young person who gradually loses drive and motivation and starts to drift away from friends. After months or even years of this deterioration, more obvious signs of disturbance such as delusional ideas or hallucinations, appear.
This is a complicated process, millions of neurons are formed, migrate to different regions of the forming brain, and specialize to perform different functions. To support developmental theories, there are a number of risk factors for schizophrenia related to critical periods in fetal development, such as: Schizophrenia is more common in winter and spring births. Children whose mothers experienced malnutrition during the first trimester are more likely to develop schizophrenia. Pregnancy and birth complications increase the risk of developing schizophrenia. (Catherine Harrison, PhD, January 10, 2008) B.