12.1 Psychological Disorder: What Makes a Behavior “Abnormal”?

Defining Disorder

A psychological disorder is an ongoing dysfunctional pattern of thought, emotion, and behavior that causes significant distress, and that is considered deviant in that person’s culture or society (Butcher, Mineka, & Hooley, 2007). Psychological disorders have much in common with other medical disorders. They are out of the patient’s control, they may in some cases be treated by drugs, and their treatment is often covered by medical insurance. Like medical problems, psychological disorders have both biological (nature) as well as environmental (nurture) influences. These causal influences are reflected in the bio-psycho-social model of illness (Engel, 1977).

The bio-psycho-social model of illness is a way of understanding disorder that assumes that disorder is caused by biological, psychological, and social factors (Figure 12.1 “The Bio-Psycho-Social Model”). The biological component of the bio-psycho-social model refers to the influences on disorder that come from the functioning of the individual’s body. Particularly important are genetic characteristics that make some people more vulnerable to a disorder than others and the influence of neurotransmitters. The psychological component of the bio-psycho-social model refers to the influences that come from the individual, such as patterns of negative thinking and stress responses. The social component of the bio-psycho-social model refers to the influences on disorder due to social and cultural factors such as socioeconomic status, homelessness, abuse, and discrimination.

To consider one example, the psychological disorder of schizophrenia has a biological cause because it is known that there are patterns of genes that make a person vulnerable to the disorder (Gejman, Sanders, & Duan, 2010). But whether or not the person with a biological vulnerability experiences the disorder depends in large part on psychological factors such as how the individual responds to the stress he experiences, as well as social factors such as whether or not he is exposed to stressful environments in adolescence and whether or not he has support from people who care about him (Sawa & Snyder, 2002; Walker, Kestler, Bollini, & Hochman, 2004). Similarly, mood and anxiety disorders are caused in part by genetic factors such as hormones and neurotransmitters, in part by the individual’s particular thought patterns, and in part by the ways that other people in the social environment treat the person with the disorder. We will use the bio-psycho-social model as a framework for considering the causes and treatments of disorder.

Although they share many characteristics with them, psychological disorders are nevertheless different from medical conditions in important ways. For one, diagnosis of psychological disorders can be more difficult. Although a medical doctor can see cancer in the lungs using an MRI scan or see blocked arteries in the heart using cardiac catheterization, there is no corresponding test for psychological disorder. Current research is beginning to provide more evidence about the role of brain structures in psychological disorder, but for now the brains of people with severe mental disturbances often look identical to those of people without such disturbances.

Because there are no clear biological diagnoses, psychological disorders are instead diagnosed on the basis of clinical observations of the behaviors that the individual engages in. These observations find that emotional states and behaviors operate on a continuum, ranging from more “normal” and “accepted” to more “deviant,” “abnormal,” and “unaccepted.” The behaviors that are associated with disorder are in many cases the same behaviors we that engage in our “normal” everyday life. Washing one’s hands is a normal healthy activity, but it can be overdone by those with an obsessive-compulsive disorder (OCD). It is not unusual to worry about and try to improve one’s body image, but Robert’s struggle with his personal appearance, as discussed at the beginning of this chapter, was clearly unusual, unhealthy, and distressing to him.

Whether a given behavior is considered a psychological disorder is determined not only by whether a behavior is unusual (e.g., whether it is “mild” anxiety versus “extreme” anxiety) but also by whether a behavior is maladaptive—that is, the extent to which it causes distress (e.g., pain and suffering) and dysfunction (impairment in one or more important areas of functioning) to the individual (American Psychiatric Association, 2000)¹. An intense fear of spiders, for example, would not be considered a psychological disorder unless it has a significant negative impact on the sufferer’s life, for instance by causing him or her to be unable to step outside the house. The focus on distress and dysfunction means that behaviors that are simply unusual (such as some political, religious, or sexual practices) are not classified as disorders.

Put your psychology hat on for a moment and consider the behaviors of the people listed in Table 12.2 “Diagnosing Disorder”. For each, indicate whether you think the behavior is or is not a psychological disorder. If you’re not sure, what other information would you need to know to be more certain of your diagnosis?

A trained clinical psychologist would have checked off “need more information” for each of the examples in Table 12.2 “Diagnosing Disorder” because although the behaviors may seem unusual, there is no clear evidence that they are distressing or dysfunctional for the person. Talking to ourselves out loud is unusual and can be a symptom of schizophrenia, but just because we do it once in a while does not mean that there is anything wrong with us. It is natural to be depressed, particularly in the long winter nights, but how severe should this depression be, and how long should it last? If the negative feelings last for an extended time and begin to lead the person to miss work or classes, then they may become symptoms of a mood disorder. It is normal to worry about things, but when does worry turn into a debilitating anxiety disorder? And what about thoughts that seem to be irrational, such as being able to “speak the language of angels”? Are they indicators of a severe psychological disorder, or part of a normal religious experience? Again, the answer lies in the extent to which they are (or are not) interfering with the individual’s functioning in society.

Another difficulty in diagnosing psychological disorders is that they frequently occur together. For instance, people diagnosed with anxiety disorders also often have mood disorders (Hunt, Slade, & Andrews, 2004), and people diagnosed with one personality disorder frequently suffer from other personality disorders as well. Comorbidity occurs when people who suffer from one disorder also suffer at the same time from other disorders. Because many psychological disorders are comorbid, most severe mental disorders are concentrated in a small group of people (about 6% of the population) who have more than three of them (Kessler, Chiu, Demler, & Walters, 2005).

Diagnosing Disorder: The DSM

Psychologists have developed criteria that help them determine whether behavior should be considered a psychological disorder and which of the many disorders particular behaviors indicate. These criteria are laid out in a 1,000-page manual known as the Diagnostic and Statistical Manual of Mental Disorders (DSM), a document that provides a common language and standard criteria for the classification of mental disorders (American Psychiatric Association, 2000)¹. The DSM is used by therapists, researchers, drug companies, health insurance companies, and policymakers in the United States to determine what services are appropriately provided for treating patients with given symptoms.

The first edition of the DSM was published in 1952 on the basis of census data and psychiatric hospital statistics. Since then, the DSM has been revised five times. The last major revision was the fourth edition (DSM-IV), published in 1994, and an update of that document was produced in 2000 (DSM-IV-TR). The fifth edition (DSM-V) is currently undergoing review, planning, and preparation and is scheduled to be published in 2013. The DSM-IV-TR was designed in conjunction with the World Health Organization’s 10th version of the International Classification of Diseases (ICD-10), which is used as a guide for mental disorders in Europe and other parts of the world.

As you can see in Figure 12.7, the DSM organizes the diagnosis of disorder according to five dimensions (or axes) relating to different aspects of disorder or disability. The axes are important to remember when we think about psychological disorder, because they make it clear not only that there are different types of disorder, but that those disorders have a variety of different causes. Axis I includes the most usual clinical disorders, including mood disorders and anxiety disorders; Axis II includes the less severe but long-lasting personality disorders as well as mental retardation; Axis III and Axis IV relate to physical symptoms and social-cultural factors, respectively. The axes remind us that when making a diagnosis we must look at the complete picture, including biological, personal, and social-cultural factors.

The DSM does not attempt to specify the exact symptoms that are required for a diagnosis. Rather, the DSM uses categories, and patients whose symptoms are similar to the description of the category are said to have that disorder. The DSM frequently uses qualifiers to indicate different levels of severity within a category. For instance, the disorder of mental retardation can be classified as mild, moderate, or severe.

Each revision of the DSM takes into consideration new knowledge as well as changes in cultural norms about disorder. Homosexuality, for example, was listed as a mental disorder in the DSM until 1973, when it was removed in response to advocacy by politically active gay rights groups and changing social norms. The current version of the DSM lists about 400 disorders. Some of the major categories are shown in Table 12.3 “Categories of Psychological Disorders Based on the “, and you may go to http://en.wikipedia.org/wiki/DSM-IV_Codes_(alphabetical) and browse the complete list.

Although the DSM has been criticized regarding the nature of its categorization system (and it is frequently revised to attempt to address these criticisms), for the fact that it tends to classify more behaviors as disorders with every revision (even “academic problems” are now listed as a potential psychological disorder), and for the fact that it is primarily focused on Western illness, it is nevertheless a comprehensive, practical, and necessary tool that provides a common language to describe disorder. Most U.S. insurance companies will not pay for therapy unless the patient has a DSM diagnosis. The DSM approach allows a systematic assessment of the patient, taking into account the mental disorder in question, the patient’s medical condition, psychological and cultural factors, and the way the patient functions in everyday life.

Diagnosis or Overdiagnosis? ADHD, Autistic Disorder, and Asperger’s Disorder

Two common critiques of the DSM are that the categorization system leaves quite a bit of ambiguity in diagnosis and that it covers such a wide variety of behaviors. Let’s take a closer look at three common disorders—attention-deficit/hyperactivity disorder (ADHD), autistic disorder, and Asperger’s disorder—that have recently raised controversy because they are being diagnosed significantly more frequently than they were in the past.