Abnormal Behaviour can be inherited. Twin studies develop concordance rate - low for some (phobias) (MZ). High for others (Schizophrenia) (lots of genes). Genes responsible for abnormal behaviours - product of evolution (traits may not be useful anymore)
Neurotransmitters are thought to be imbalanced in the nervous system of people suffering from psychological disorders. Excessive amounts of dopamine have been associated with schizophrenia. Depression has been associated with low levels of serotonin. Coristol is associated with depression.
Flu has been linked to schizophrenia.
Can give rise to mental illness.
14% os schizophrenia patients linked to exposure of flu in first trimester.
Syphilis - identified as causing brain damage leading to general paresis.
Abnormal behaviour can occur if the structure of the brain is damaged in some way. An example is that of enlarged ventricles. Ventricles are sacks of fluid in our brain, people with schizophrenia tend to have larger ventricles than the normal population. Another example is Alzheimer's disease, a type of dementia caused by the loss of cells in the nervous system.