The Psychological Disorders

In these notes I discuss the psychological disorders: their classification and reclassification, behavioral "symptoms," and, in selected cases where something is known about it, heritability and underlying physiological changes.

Classification of the Psychological Disorders

In medicine, classification of the various medical disorders typically is based on the particular combinations of symptoms that patients present to the physician; the physician then renders a diagnosis based on those symptoms. Thus, if a patient comes into the doctor's office complaining about chills and fever, muscular aches and pains, nausia, and so, the physician might conclude from these symptoms that the patient has the flu. The idea here is that patients who present the same symptoms are probably suffering from the same underlying disorder, a common cause for which there will be a specific treatment. Psychiatrists, clinical psychologists, and other mental health workers confonted with a variety of behavioral, cognitive, and emotional "symptoms" of their clients likewise began to identify combinations of these symptoms that seemed to hang together, forming a particular "syndrome" that differentiated these particular cases from others. Category lables were developed for the different syndromes and it was hoped that those falling into the same category might turn out to be suffering from the same set of underlying causes of their condition. Thus was born labels such as "schizophrenia," "hysteria," and "manic-depressive psychosis.

Such labels can be very helpful to practitioners. They make it relatively easy to communicate the major features of a person's disorder to other practioners, as everyone in the field knows what sorts of abnormalities a person diagnosed, for example, as "schizophrenic" is likely to display. And once a person has been identified as having a particular disorder, this immediately suggests which treatments are likely to be the most beneficial to the client.

On the negative side, however, it is too easy to label someone as "a schizoprenic" and forget that one is dealing with an individual human being and not merely a collection of symptoms. Furthermore, nonspecialists soon learned that to be labeled a schizophrenic, manic-depressive, or psychpathic personality was not exactly an honor, and as the general public became more familiar with the typical symptoms of the various disorders, they tended to use them as stereotypes, as if everyone with the label "schizophrenic" exhibited the entire set of symptoms in their most extreme forms. Developing category labels for these disorders may have been necessary, but it did not always have positive consequences for those who were being pinned with the label.

The initial system of categories developed slowly over decades and in some ways proved unsatisfactory in practice. Eventually the American Psychiatric Association conviened a committe to develop a new classification system that would reorganize some of the major categories and provide additional ones based on the latest information. The result of the committee's deliberations was a publication called the Diagnostic and Statistical Manual or DSM. Over the years this has been revised several times, the current revision is the DSM IV.

The old classification system included two main types of psychological disorder which differ in severity and characteristic problem: Neurosis and Psychosis. Although these are no longer considered current, I'll start with these two types, as I believe that they still offer a way to differentiate certain of the classes of disorder now included in the new scheme as presented in the DSM:

The major category of neurosis has been replaced by several more specific categories in the current scheme of classification. I'll take up those milder disorders that would have fallen under "neurosis" first, beginning with the "anxiety disorders."

The Anxiety Disorders

The Somatoform Disorders

"Soma" means "body," so these are disorders with some obvious connection to the state of the body. Included are the following two diagnoses:

The Dissociative Disorders

This category includes those psychological disorders that involve a "walling off" of some part of the mind from consciousness. (The walled off parts are said to become "dissociated." At one time conversion disorder was included here, but evidently it was needed above so that somatoform disorders would include more than just hypochondriasis!

This completes my review of disorders that fell under the older category of "neurosis." Next I cover two more severe disorders, involving a loss of contact with reality and other extreme symptoms, that fall under the old category of "psychosis."


Although the term "schizophrenia means "split mind," it does not refer to the splitting of the personality into several functioning personality subtypes as in dissociative identity disorder. Rather, the term was intended to convey a splitting of the normally integrated cognitive/behavioral/emotional functioning of the brain. For example, a person may suddenly become emotionally agitated even though there is no apparent objective reason for this change.

Symptoms of Schizophrenia

Schizophrenia includes a variety of symptoms, not all of which will necessarily be present at any one time.

Classification of Schizophrenia

Schizophrenia may be broken into two classes according to the rapidity of its development:

Causes of Schizophrenia

The causes of schizophrenia are unknown. Genetic factors may somewhat dispose one to develop the disorder, but even among identical twins, if one develops schizophrenia, the other has only about a 50-50 chance of developing it also, so there must be other precipitating factors. It is now known that there is some degree of brain deterioration associated with the disorder, at least in those diagnosed with "process" schizophrenia. A biochemical imbalance involving the neurotransmitter dopamine is implicated in the disorder, as drugs the have proven effective in reducing the symptoms of schizophrenia tend to be those that reduce activity in the brain's dopamine systems.

Bipolar Disorder (Manic-Depressive Disorder)

Bipolar Disorder gets its name from the fact that the person alternates between two "poles" along a continuoum of emotion running from mania at one extreme to severe depression at the other. In most cases, the person cycles between these two extremes over a period of days, weeks, or months, with periods of apparent normality in between. During the manic phase the person exhibits agitation, an emotional high where everything seems possible, high energy with little apparent need for sleep, a flood of ideas coming one right after the other, and irrationalty. During the depressive phase the opposite is evident: little energy, difficulty in initiating activity, slowed thought processes, serious depression. Irrationality is again present -- the person may believe that he or she has done some horrible thing for which they are being punished, for example.

As with schizophrenia, there is some evidence that genetics is a factor in that relatives of someone with the disorder are somewhat more likley than nonrelatives also to develop it, but the actual causes remain unknown. The disorder appears to relate to a problem in the regulation of synaptic sensitivities in a certain class of neurotransmitters; one of the effective drug treatments, lithium chloride, may act to stabilize this sensitivity and thereby stop the cycling.