Mental illness involves both physical and psychological components. The combined effects of these different factors generally result in behavioral dysfunction. The disease, schizophrenia, is a heterogenous disorder involving numerous signs and symptoms. Although its exact etiology remains unknown, several causal factors are thought to be involved. Physical and psychological factors may first predispose a person to schizophrenia, and then trigger the illness. Multiple therapeutic modalities may be used to treat the condition.
Modern medical thinking may have originated with Hippocrates. As far back as the fifth century B.C., Hippocrates hypothesized that mental illnesses had physical causes. He saw the brain as "the organ of consciousness"--the site of both intellect and emotion. Such ideas eventually led to theories of somatogenesis. Hippocrates believed that deviant thinking corresponded to brain pathology.
More recently, 19th century physician, Wilhelm Griesinger, also proposed that mental disorders have some physiological cause. In 1883 a follower of Griesinger, Emil Kraepelin, published a book delineating the "organic nature" of various mental illnesses. He regarded the individual diseases as distinct; according to Kraepelin, mental illnesses each had their own symptoms, etiology, course, and prognosis.
Towards the end of the 1800s, significant progress was also achieved in the neurological sciences. This work eventually provided both structural and functional information on the brain. An exceedingly complex organ, the human brain contains literally billions of neurons. It is now known that each neuron is composed of certain specific components. For example, all neurons have dendrites, a cell body, an axon, and a synapse. Nerve cell function generally involves stimulation of the cell body or dendrites. This transient alteration of the neuron's membrane potential subsequently travels down the axon to...