How Are Mental Disorders Conceptualized and Classified?
The chapter begins with a consideration of how disorders are conceptualized and classified. Again, abnormality is a cultural judgment, and particular behaviors may be seen as deviant in one society but unremarkable in another. In American society, the symptoms of a disorder must interfere with a least one aspect of a person's life—such as work, social relations, and self-care. Health care professionals use the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) to identify psychological disorders. The DSM has been around for more than 50 years, and in its current fourth edition, psychopathology is described in terms of observable symptoms. Individuals are diagnosed on a multiaxial scale, including clinical syndromes, personality disorders, general medical conditions, psychosocial stressors, and global assessment of functioning. However, the DSM-IV gives little information about the cause, prognosis, or treatment of disorders.

The authors review some of the classic models of psychopathology (psychoanalytic, family systems, sociocultural, cognitive-behavioral). Most ideas of cause involve multiple factors and incorporate some aspect of the diathesis-stress model. This is the idea that disorders are the result of an underlying predisposition (diathesis) which is made evident by environmental stress.

Finally, the authors look at the differences between the psychological concept of mental disorders and the legal concept of insanity. Most people mistakenly believe that the insanity defense is a common strategy to avoid criminal prosecution. In actuality, competency to stand trial is a more common area in which one's mental functioning comes into question.

Table 16.1: Definitions of Insanity
Insanity Rule	Definition
M'Naughten	person does not know right from wrong
Durham	behavior is the result of mental illness or mental defect
American Law Institute	mental illness or defect led to a lack of capacity to appreciate the criminality of the act or to an inability to conform to the law

Can Anxiety Be the Root of Seemingly Different Disorders?
The next section begins the consideration of specific psychological disorders. The anxiety disorders are characterized by excessive anxiety in the absence of true danger. Within this category, the phobias involve excessive fear of a specific object or situation. Most students will be familiar with specific phobias (e.g, claustrophobia, acrophobia, hydrophobia) that involve discrete events or objects. Most students also will have empathy for the social phobias which involve the fear of being negatively evaluated by others, fear of public speaking, and fear of eating in front of others.

Individuals with generalized anxiety disorder are constantly anxious and worry about trivial matters. Panic disorder involves sudden and overwhelming attacks of terror and often results in agoraphobia, the fear of being in a public situation from which escape is difficult. Obsessive-compulsive disorder (OCD) involves intrusive thoughts that are dealt with through maladaptive, repetitive actions. Numerous theories have been proposed to explain the anxiety disorders, and they certainly involve the cognitive misperceptions of actual danger. Recent advances in neurophysiology have related obsessive-compulsive disorder to dysfunction in the caudate nucleus and panic disorder to abnormality in the locus coeruleus.

Are Mood Disorders Extreme Manifestations of Normal Mood?
The mood disorders, which involve extreme emotions, include one of the most common diagnostic categories—major depression. Individuals with this disorder show symptoms such as depressed mood, loss of interest in pleasurable activities, weight changes, sleep disturbances, difficulty concentrating, guilt, and suicidal ideation. A milder form of depression, dysthymia, involves depressed mood for at least 2 years. Moods can also swing from depression to mania, as is seen in bipolar disorder, or from mild depression to hypomania, as is seen in cyclothymia. A strong genetic component has been implicated in bipolar disorder. A genetic component has been found for major depression also, but it has not been as strong.

Major depression has been linked to the neurotransmitters norepinephrine and serotonin. Indeed, medications such as Prozac that selectively increase serotonin have had a huge impact on treatment since the early 1990s. Depression has also been associated with maladaptive cognitions (e.g., Beck's cognitive triad), errors in logic, and learned helplessness. Finally, life stressors can precipitate an episode of major depression; however, the effects of these events can be attenuated by the presence of close friends

Is Schizophrenia a Disorder of Mind or Body?
Schizophrenia is one of the most devastating of all the mental disorders in terms of its effect on the victim and family. Although it often is erroneously referred to as “split personality,” the splitting in schizophrenia is between thought and emotion. Schizophrenia is a psychotic disorder, characterized by alterations in thought, perceptions, or consciousness. The rate of schizophrenia in the population is about 1% and has remained relatively stable across time and among cultures. Although the DSM-IV lists various subtypes of schizophrenia (paranoid, disorganized, catatonic, undifferentiated, residual), they can also be classified by positive and negative symptoms. The positive symptoms of schizophrenia involve excesses of behavior and include delusions, hallucinations, and loosening of associations. The negative symptoms of schizophrenia involve deficits in functioning and include isolation, withdrawal, and apathy. Schizophrenia has a strong biological component, and the positive symptoms often are dramatically reduced by antipsychotic medication. Unfortunately, the negative symptoms of schizophrenia tend to persist, which has led investigators to hypothesize that this form of schizophrenia is related to structural brain abnormalities. One recent hypothesis regarding the cause of schizophrenia is that it is related to a slow-acting virus that becomes evident in symptomatology when an individual reaches young adulthood.

Are Personality Disorders Truly Mental Disorders?
The personality disorders are a controversial category of disorders marked by inflexible and maladaptive ways of interacting with the world. While the DSM-IV lists three categories of personality disorders by general behavior (odd/eccentric, dramatic/emotional/erratic, anxious/fearful), there is considerable overlap among the traits in the individual disorders. This has led to a reduction in reliability of diagnosis. Two of the personality disorders that have received considerable research investigation are borderline personality disorder and antisocial personality disorder.

Borderline personality disorder is characterized by a poor sense of self, emotional instability, and impulsivity. These individuals can be very dramatic and exhibit self-mutilation or suicidal behaviors. Borderline personality disorder has been linked to low serotonin levels and a history of physical and/or sexual abuse. Individuals with antisocial personality disorder demonstrate little empathy for others or remorse for their self-gratifying behaviors. This disorder is seen frequently in prison populations and has been related to low levels of arousal, poor response to punishment, and deficits in frontal lobe functioning.

Should Childhood Disorders Be Considered a Unique Category?
The final category, childhood disorders, remains controversial, because children show varied rates of development. What is seen as abnormal at one stage may be normal at another. Autism is a severe childhood disorder characterized by deficits in social interaction, impaired communication, and restricted interests. It is hard to believe that not long ago this disorder was associated with poor parenting; whereas, today it is understood to have a largely biological cause. Genetic and neurochemical research appears to have tremendous promise in improving our understanding and treatment of autistic behaviors.

Attention-deficit/hyperactivity disorder (ADHD) has received considerable research and media attention in recent years. ADHD children are characterized by restlessness, inattention, and impulsivity. The unfortunate aspect of these symptoms is that they are associated with academic, social, and vocational underachievement. ADHD has been related to poor parenting and sociocultural factors; however, there also is a clear genetic component. Noted deficits in functioning in the frontolimbic system and caudate nucleus provide potential areas for future treatments.