Classifying Psychological Disorders

Classification of psychological disorders requires that symptoms be identified; sets of symptoms form a syndrome. Several of the most prevalent of the DSM‐IV's 16 categories of disorders follow.

Anxiety disorders. Anxiety is a diffuse, extremely unpleasant feeling of vulnerability, apprehension, and fear. Symptoms of anxiety disorders include motor tension (trembling, jumpiness, inability to relax), hyperactivity (racing heart, dizziness, perspiration), and apprehension (disturbing thoughts). The following five (of the thirteen in the DSM‐IV) types of anxiety disorders are well known.

  • A generalized anxiety disorder (GAD) is a condition characterized by excessive anxiety and worrying, occurring more days than not for a period of at least six months. Anxiety is not triggered by any particular object or event but seems to be what Freud called free‐floating anxiety, anxiety that is general and pervasive.

  • A phobic disorder is marked by a continual, irrational fear of a specific situation or object such as snakes, heights, being closed in a small place, or leaving the home environment. Each phobia has a different name depending on the thing feared, such as acrophobia, a fear of high places; agoraphobia, a fear of open spaces; and social phobia, a fear of social or performance situations in which embarrassment may occur.

  • A panic disorder is characterized by a chronic state of tension that can erupt in sudden episodes of intense panic or dread that last several minutes (or hours) and may include a variety of symptoms such as chest pains, trembling, and dizziness.

  • An obsessive‐compulsive disorder is an extreme preoccupation with certain thoughts and compulsive performance of particular behaviors. An obsession is the unsolicited reoccurrence of disturbing thoughts; a compulsion is a repetitive behavior (such as checking door locks) or mental activity (counting, praying, etc.) that one feels compelled to do, even against one's will. An example of the disorder is the compulsion to wash one's hands repeatedly, often to the extent of making them sore.

  • A post‐traumatic stress disorder is characterized by the reexperiencing of a traumatic event, symptoms of increased arousal, avoidance of reminders of the original trauma, and diminished interest in daily activities. Many war veterans retain vivid memories of (flashbacks) and nightmares about traumatic events experienced during battle.

While the causes of anxiety disorders are not completely understood, it is generally believed that some of the disorders (such as specific phobias, obsessive‐compulsive disorders, and panic disorders) may have a genetic basis. One cause may be the inadequate action of the neurotransmitter gamma‐aminobutyric acid (GABA). Certain drugs, such as Valium and Librium, which increase the sensitivity of the GABA receptors, help reduce anxiety.

Somatoform disorders. A somatoform disorder is characterized by one or more symptoms of a physical dysfunction but for which there is no identifiable organic cause. Following are two examples (from seven in the DSM‐IV).

  • A conversion disorder is a condition manifested by a physical dysfunction (blindness, deafness, paralysis, numbness, etc.) that has no underlying organic basis. This condition (formerly called hysteria) allows escape from an anxiety‐provoking activity. For example, an athlete who dreads competing in an event, might develop a numb arm and effectively avoid the event.

  • Hypochondriasis is characterized by a continuing belief that one has one or more serious illnesses although no medical evidence supports the belief. An occasional headache, for example, may be interpreted by a hypochondriac as a brain tumor even though medical tests do not support this interpretation.

Dissociative disorders. In dissociative disorders, a part of an individual's personality becomes separate (dissociated) from other parts, producing a lack of integration of identity, memory, or consciousness. The DSM‐IV lists five forms; the three most common follow.

  • In dissociative amnesia, an individual develops a sudden inability to recall important personal information (such as her or his name); the disorder often follows psychological trauma. The memory loss cannot be attributed to physical trauma, a particular medical condition, or direct effects of drugs. Memory recall may occur suddenly or gradually.
  • People experiencing a dissociative fugue suddenly and unexpectedly travel away from their home or customary place of activities and are unable to recall some or all of their past. They are confused about their personal identity, may not remember who they are, and sometimes assume a new identity. Recovery may be rapid.
  • A dissociative identity disorder (formerly, multiple personality disorder) is characterized by the assuming of two or more distinct, integrated personalities, each of which manifests itself at times. The behaviors are accompanied by an inability, too extensive to be explained by ordinary forgetfulness, to recall important personal information. One personality may have no memory of the other(s). Often these disorders stem from childhood trauma such as sexual abuse.

Mood disorders. Mood disorders are characterized primarily by a disturbance in mood. (Remember, however, that all psychological disorders affect one's mood, or affect.) Two mood disorders (from four in the DSM‐IV) are described below in more detail.

  • In major depressive disorder, a person, for no apparent reason, experiences at least two or more weeks of depressed moods, feelings of worthlessness, and diminished interest or pleasure in most activities. To be classified as a major depressive disorder, the episode must be accompanied by clinically significant distress and impairment in social, occupational, or other areas of daily living.

  • In a bipolar disorder, a person alternates between the hopelessness and lethargy of depression and the overexcited state of mania. Mania is manifested by hyperactivity and wild excitement. A person suffering from this disorder may lose control and act very inappropriately and sometimes destructively. (Subcategories of bipolar disorders are classified depending on the ratios of manic and depressive episodes.)

The causes of mood disorders have been the subject of much research. It is known that genetic factors are involved. (If one identical twin is diagnosed as having a major mood disorder, the chances are one in two that the other twin will also suffer such a disorder.) Biochemical factors also play a role. Norepinephrine, a neurotransmitter, is present in excessive amounts during mania and at low levels during depression. Serotonin, another neurotransmitter, is at low levels during depression. Drugs that regulate the level of these neuro‐transmitters (tricyclic antidepressants; monoamine oxidase, MAO, inhibitors; and selective serotonin‐reuptake inhibitors, SSRIs) are used for treatment of the depressions. Research has also shown that cognitive factors, such as self‐defeating reactions to events, contribute to the development of depression. An individual who accepts sole blame for all of life's happenings is more likely to develop depression.

Schizophrenia and other psychotic disorders. Schizophrenic disorders are severe disorders characterized by distorted thoughts and perceptions, atypical communication, inappropriate emotion, abnormal motor behavior, and social withdrawal. The slow‐developing schizophrenia known as chronic or process schizophrenia has a poor prognosis for recovery; when a formerly well‐adjusted individual develops schizophrenia (known as reactive or acute schizophrenia), there is a better chance of recovery. The five major types of schizophrenia are as follows.

  • Paranoid schizophrenia is characterized by prominent delusions or auditory hallucinations in the context of relative preservation of usual cognitive functioning and affect. (Examples are delusions of persecution, grandeur, or both.) Paranoid schizophrenics trust no one and are constantly on guard because they are convinced that others are plotting against them. They may seek retaliation against imagined enemies.

  • Catatonic schizophrenia is evidenced by excessive, sometimes violent motor activity or by a mute, unresponsive, stuporous condition in which a person may retain the same posture for hours. A person may remain in one state for a long period or alternate between violent activity and remaining stiff and immobile, totally unresponsive to the outside world.

  • Disorganized (hebephrenic) schizophrenia is characterized by bizarre symptoms, including extreme delusions, hallucinations, and inappropriate patterns of speech, mood, and movement. Inappropriate moods may be manifested by laughing or crying at unsuitable times.

  • Undifferentiated schizophrenia is manifested by delusions, hallucinations, incoherent speech, and disorganized behavior. The conglomerate of symptoms fit the criteria of more than one type or of no clear type of schizophrenia.

  • Residual schizophrenia is a condition in which at least one episode of schizophrenia has occurred although there are currently no prominent psychotic symptoms (for example, delusions or hallucinations). Certain negative symptoms, those indicating a lack, such as flat affect, poverty of speech, and avolition (lack of using the will, or choosing), continue, however, as do two or more attenuated positive symptoms (eccentric behavior, odd beliefs, and so forth). The course of this type of schizophrenia may be time limited and may represent a transitional phase between remission and a full‐blown psychotic episode.

The causes of schizophrenia are complex and still not completely understood. It is known that genetic factors are involved because schizophrenia is found repeatedly in certain families; adult children of schizophrenic parents are more likely to develop schizophrenia than are children of nonschizophrenic parents. However, inheritance does not completely explain the etiology (cause) of schizophrenia (only 46% of identical twins of schizophrenic twins develop the disorder), and currently, a biochemical factor is also deemed important. Autopsies on some schizophrenics have found an excess of dopamine receptors, and drugs that block the activity of that neurotransmitter help control schizophrenic symptoms. In addition, misuse of amphetamines, which are similar to dopamine and which may increase the level of dopamine in the brain, produces many symptoms similar to those found in schizophrenia. In the brain structures of schizophrenics, other variations from the norm also occur, such as a smaller thalamus and enlarged ventricles. The complete etiology of schizophrenia remains a focus of research in psychopathology.

Personality disorders. Personality disorders are longstanding, maladaptive, and inflexible ways of relating to others, and the behaviors or symptoms characteristic of them usually begin in childhood or adolescence. Those with personality disorders may function adequately and be regarded simply as eccentric, but when they are faced with an extremely stressful situation, they can respond only rigidly and narrowly. The eleven types of personality disorders are classified in three groups, or clusters, based on their similarities. The disorders often emerge during childhood, adolescence, and early adulthood and continue into adult life.

  • Cluster A—disorders of odd/eccentric reactions
  • A paranoid personality disorder is manifested by a pervasive distrust and suspiciousness of others and a tendency to interpret the actions of others as malevolent or threatening.

  • A schizoid personality disorder is characterized by a tendency to be indifferent to social relationships and by restricted expression of emotions in interpersonal settings.

  • Those with a schizotypal personality disorder display eccentric ways of thinking, perceiving, communicating, and behaving and are acutely uncomfortable in close relationships.

  • Cluster B—disorders of dramatic, emotional, or erratic reactions
  • Individuals with an antisocial personality disorder manifest a pervasive tendency to disregard and to violate the rights of others.
  • A borderline personality disorder is characterized by instability of interpersonal relationships, self‐image, and emotions as well as by marked impulsivity.
  • Those with a histrionic personality disorder exhibit pervasive and excessive emotionality and attention‐seeking behavior.
  • Manifestations of a narcissistic personality disorder include a pervasive pattern of grandiosity, a need for admiration, and a lack of empathy.
  • Cluster C—disorders involving anxiety and fearfulness
  • Those with an avoidant personality disorder exhibit, in a variety of contexts, a pervasive pattern of social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluations.

  • Those with a dependent personality disorder allow others to make decisions and display a need to be taken care of that leads to submissive and clinging behavior accompanied by fears of separation.

  • An obsessive‐compulsive personality disorder involves, in many contexts, a tendency toward perfectionism, a rigid preoccupation with orderliness, and mental and interpersonal control at the expense of flexibility, openness, and efficiency.

  • A disorder termed a personality disorder not otherwise specified is one that does not meet the criteria for a specific personality disorder but in which the combination of symptoms causes clinically significant distress or impairment in functioning.

Delirium, dementia, amnestic, and other cognitive disorders. Cognitive disorders involve a clinically significant deficit in cognition or memory that represents a marked change from a previous level of functioning. The disorders are usually further categorized based on their presumed etiology.

  • A delirium is characterized by a disturbance in consciousness and a change in cognition that develop over a short time. Some examples are delirium due to a medical condition, and substance‐induced delirium (such as caused by a drug of abuse or a toxin). Drugs that are listed as causing the condition include alcohol, amphetamines, caffeine, cocaine, hallucinogens, inhalants, marijuana, nicotine, opiates, phencyclidine (PCP), sedatives, and other unspecified chemicals. Substance withdrawal may also produce a delirium.

  • A dementia is characterized by multiple cognitive deficits that include memory impairment. Examples are dementia of Alzheimer's type, vascular dementia, and dementia due to HIV disease.

  • An amnestic disorder is shown by multiple cognitive deficits that include memory impairment, but the disorder is not connected with states of delerium or dementia. A major problem is the transfer of information from short term to long term memory. Amnestic disorders result from a physical cause such as a traumatic event (for example, a head injury incurred in an accident, during surgery, or from an electric shock), drug abuse, or the use of medications.

  • A fourth category, cognitive disorder not otherwise specified, is used to delineate a cognitive dysfunction presumed to be due to a general medical condition or substance use but that does not meet the other diagnostic criteria.

Eating disorders. Eating disorders are characterized by severe disturbances in eating behavior.

  • Anorexia nervosa is characterized by a refusal to maintain a minimally normal weight, intense fear of gaining weight, and distortion in the perception of the shape or size of one's body. Postmenarcheal females with this condition are often amenorrheic (having missed three consecutive menstrual cycles). Muscular weakness and osteoporosis (bone loss) may also occur.

  • Bulimia nervosa is manifested by binge eating and use of inappropriate techniques, such as purging or use of laxatives, to prevent weight gain. To qualify for this diagnosis, an individual must engage in binge eating and the inappropriate compensatory acts (purging, use of laxatives), on average, twice a week for three months.

Other disorders. DSM‐IV diagnostic categories not described above include “substance‐related disorders”; “disorders usually first diagnosed in infancy, childhood, or adolescence”; “sexual and gender identity disorders”; “sleep disorders”; “impulse‐control disorders not elsewhere classified”; “adjustment disorders”; and “other conditions that may be a focus of clinical attention.”