Page 483 - Understanding Psychology

Figure 16.12 The Genain Quadruplets
In 1930 four identical girls were born. By high school, people had labeled the girls as somehow different. By the time they were young adults, all four were diagnosed with schizophrenia. From this case, what can psychologists infer about the causes of schizophrenia?
Chemical problems may also be involved in the occurrence of schizophrenia. A number of researchers believe that the basic problem in schizophrenia is that too much or too little of certain chemicals has upset the brain’s mechanisms for processing information, perhaps interfering with normal synaptic transmission.
The dopamine hypothesis suggests that an excess of dopamine at selected synapses is related to a diagnosis of schizophrenia. One psychol- ogist (Carlsson, 1988) notes that correlational studies are not enough to demonstrate a direct role for dopamine in schizophrenia. It seems likely that chemicals play a role, but it is hard to tell whether these chemicals are the cause of schizophrenia or the result of it. Symptoms of schizo- phrenia may even be caused by the fact that people with schizophrenia tend to live in hospitals, where they get little exercise, eat institutional food, and are usually given daily doses of tranquilizers. Living under such conditions, anyone might develop chemical imbalances and abnormal behavior.
The use of CAT and MRI scans (see Chapter 6) has led to the dis- covery that the brains of people with schizophrenia often show signs of deteriorated brain tissue (Pearlson et al., 1989). One consistent result is that women who at some time develop schizophrenia are likely to have difficult pregnancies and difficulties giving birth. Obesity prior to preg- nancy, infection during the second trimester (Wyatt & Susser, 2000), and oxygen deprivation to the fetus (Cannon et al., 2000) are correlated with children developing schizophrenia. The exact role of the environ- ment in fostering schizophrenia is unclear, but it is involved.
Chapter 16 / Psychological Disorders 469