Mariella, a 19-year-old college freshman, has been repeatedly asking herself, “What’s going on?” and “What should I do?” Something was not right. Mariella was outgoing, bright, and cheery in high school but was now fatigued, blue, and pessimistic in college. She was starting her second semester and thought the tough college adjustment period her friends and family talked about should be over by now. Were her feelings of fatigue and discontent just a temporary “funk,” or was something seriously wrong? Mariella’s fatigue and discontent began early in her first semester and worsened toward finals week. She enrolled in five courses and was soon overwhelmed by extensive reading assignments, large classes, and fast-approaching deadlines. She struggled to finish her work, often seemed isolated from others, and felt unimportant in the huge academic setting. Mariella believed no one cared whether she was in class, and she longed for days in high school when she interacted with a close-knit group of teachers and friends. Her college professors seemed to treat her like a number and not a student, and her classmates always seemed to be rushing about with little time to talk. Mariella was an “A” student in high school but was now struggling to get Cs in her college classes. She had great trouble concentrating on what she read, which led to low test scores. Mariella did talk to her friends and family members back home about her troubles, but no one truly understood what she was going through. Instead, they thought Mariella was experiencing simple, normal homesickness that would soon end. Mariella began spending more time alone as her first semester approached mid-November. She often slept, watched television, listened to music, and went online. She no longer found much enjoyment doing things that used to appeal to her, such as going to the movies and playing the guitar. Mariella declined invitations from others to go out, and her roommate noticed that Mariella seemed sad and lonely. Unfortunately, no one took the time to ask Mariella if something serious might be wrong. Mariella also lost significant weight her first semester. When she went home for Thanksgiving, her family members were surprised at how she looked. Mariella had noticed no major change except for occasional hunger, but in fact she had lost 10 pounds from her 120-pound frame. Unfortunately, she received flattering comments on how she looked, so the larger problem of her sad mood went undetected. Her concentration and eating problems continued when she returned to school to finish her first semester, and Mariella struggled to finish her final examinations and receive passing grades. Mariella was happy to return home for the winter break and hoped her feelings of fatigue and discontent were simply related to school. Unfortunately, she remained sad, did not regain lost weight from the previous semester, and continued to sleep much of the day. She dreaded returning to school but felt pressure from others to do so. Mariella became quite despondent when she returned to school in mid-January. She knew something would have to change to endure this second semester, but she felt confused and unsure. Once again, she was asking, “What’s going on?” and “What should I do?” What Do You Think?
1. Why do you think Mariella feels the way she does?
2. What should Mariella do? What would you do if in her situation?
3. Which aspects of Mariella’s story concern you most?
4. Do you know people who have had similar experiences? What did they do?
5. What should Mariella’s friends and family do to help?
Introduction I f Mariella had lived centuries ago, demonic possession might have been a common explanation for her problems. Scientists and mental health professionals today, however, focus on a person’s biology, environment, and other factors to help people like Mariella. Scientists and mental health professionals develop perspectives or models—ways of looking at things—to piece together why someone like Mariella has problems. Perspectives or models are systematic ways of viewing and explaining what we see in the world. When you try to explain high prices for an item, you might think about the economic model of supply and demand to conclude everyone wants the item but supplies are limited. Or if a friend of yours is sick, you might think about the disease model of germ theory to ask whether she was around a sick person or if she ate spoiled food. Mental health professionals use models to help explain unusual behavior or mental disorders in people like Mariella. Five main models to explain mental disorders are described in this chapter: • The biological model focuses on genetics, neurotransmitters, brain changes, and other physical factors. • The psychodynamic model focuses on internal personality characteristics. • The humanistic model focuses on personal growth, choice, and responsibility. • The cognitive-behavioral model focuses on special thoughts and learning experiences. • The sociocultural model focuses on external environmental events and includes the family systems perspective
FIGURE 2.1 THE USE OF MODELS. Models or perspectives affect the way we think about causes of mental disorder, our methods of assessment, and our methods of prevention and treatment.
These models dominate the mental health profession today and influence the way we think about, assess, and treat mental disorders (see Figure 2.1). Each model has strengths and weaknesses, but each provides mental health professionals with ways of understanding what is happening to someone like Mariella. In this chapter, we show how each model could be used to explain Mariella’s problems and help her. Many mental health professionals also integrate these models to study and explain mental disorders. The Biological Model The biological model rests on the assumption that mental states, emotions, and behaviors arise from brain function and other physical processes. This model has been in use for centuries and is stronger than ever today. Read a newspaper or magazine, watch television, or go online—countless articles, documentaries, and advertisements are available about medications and other substances to treat mental conditions. Some drug or herb always seems available to cure depression, anxiety, or sexual dysfunction. Despite the incessant advertising, however, the biological model of mental disorder, including the use of medications, is supported by scientific research that links genetics, neurochemistry, and brain changes to various psychological problems. The biological model of mental disorder was pioneered by Emil Kraepelin (1856–1926), who noticed various syndromes or clusters of symptoms in people. Mariella had a cluster of symptoms that included concentration problems, oversleeping, sadness, and weight loss. Her symptom
are commonly described within the syndrome of depression (Chapter 7). Kraepelin believed, as do many psychiatrists and other mental health professionals today, that syndromes and symptoms have biological causes. Kraepelin proposed two major types of mental disorders, each with different biological causes: dementia praecox (similar to schizophrenia, discussed in Chapter 12) and manic-depressive psychosis (similar to bipolar disorder, discussed in Chapter 7). Kraepelin also believed syndromes to be separate from one another, like mumps and measles, and that each syndrome has unique causes, symptoms, and outcomes. In Mariella’s case, her symptom of sadness seemed partly caused by her separation from home and led to outcomes such as poor grades. Kraepelin and many psychiatrists also believe each syndrome has its own biological cause. A psychiatrist may feel Mariella’s sadness was caused by depression that ran in her family (genetics), by a chemical (neurotransmitter) imbalance, or by some brain change. We discuss these biological causes next. Genetics Do you think Mariella’s sadness may have been present as well in some of her family members? Many mental disorders such as depression do seem to run in families. Genetic material may be involved when symptoms of a mental disorder are passed from parents to children. Genetic material refers to molecular “codes” contained in the nucleus of every human cell (Ahuja, 2014). Genes are the smallest units of inheritance that carry information about how a person will appear and behave. Genes carry information about hair and eye color, weight and height, and even vulnerability to diseases such as lung cancer or mental disorders such as depression. Human genes are located on 46 chromosomes or threadlike structures arranged in 23 pairs. A person’s chromosomes come half from the biological mother and half from the biological father. The genetic composition of a person is known as a genotype and is xed at birth. Genotypes produce characteristics such as eye color that do not change over time. An observable characteristic of a person is known as a phenotype, which can change over time. Observable characteristics can include intelligence, as well as symptoms of a mental disorder such as dif culty concentrating. Phenotypes can change because they result from genetic and environmental in uences. Your intelligence is partly determined by genetics from your parents but also by the type of education you received as a child. Scientists are interested in knowing which genetic and environmental in uences impact the development of emotions, cognitions, and behavior (O’Connor, 2014). This research specialty is known as behavior genetics. Behavior geneticists are interested in the degree to which a mental disorder is determined by genetics. Heritability refers to the amount of variation in a phenotype attributed to genetic factors, often expressed as a number ranging from 0 to 1. Some mental disorders such as anxiety-related disorders have modest heritability, but many major mental disorders have more substantial genetic in uences in their development (see Figure 2.2). Disorders with particularly high heritability include bipolar disorder and schizophrenia (Pearlson, 2015). Behavior geneticists also focus on what speci c genes are inherited and how these genes help produce a mental disorder. Researchers in the eld of molecular genetics analyze deoxyribonucleic acid (DNA)—the molecular basis of genes—to identify associations between speci c genes and mental disorders. Molecular genetics is quite challenging for several reasons. First, most mental disorders are in uenced by multiple genes, not just one. When you hear a media report that researchers found a gene for Alzheimer’s disease, keep in mind they likely found only one of many genes. Second, the same symptoms of a mental disorder may be caused by different genes in different people. Third, it is estimated that there are about 20,000 to 25,000 human protein-coding genes, so nding speci c ones related to a certain disorder is like nding a needle in a haystack. Despite these challenges, advances in molecular genetics will likely lead to ndings that help scientists determine how and if disorders are genetically distinct from one another. Knowledge of speci c genes can also help researchers determine how genes in uence physical changes in the body, which we discuss next FIGURE 2.2 HERITABILITY OF MAJOR MENTAL DISORDERS. Adapted from Merikangas, K.R., & Risch, N. (2005). Will the genomics revolution revolutionize psychiatry? In N.C. Andreasen (Ed.), Research advances in genetics and genomics: Implications for psychiatry (pp. 37-61). Washington, DC: American Psychiatric Publishing; Kendler, K.S., Chen, X., Dick, D., Maes, H., Gillespie, N., Neale, M.C., & Riley, B. (2012). Recent advances in the genetic epidemiology and molecular genetics of substance use disorders. Nature Neuroscience, 15, 181-189.
Nervous Systems and Neurons Physical structures in our body are affected by genetics, and this can contribute to mental disorder. The central nervous system includes the brain and spinal cord and is responsible for processing information from our sensory organs such as eyes and ears and prompting our body into action. The peripheral nervous system helps control muscles and voluntary movement, regulates the cardiovascular and endocrine (hormone) systems, assists with digestion, and adjusts body temperature. The nervous systems are composed of billions of neurons, or nerve cells, that have four major components: cell body, dendrites, axon, and terminal buttons (see Figure 2.3). A small gap called the synapse exists between neurons. Neurons communicate with each other using neurotransmitters, or chemical messengers that allow information to cross the synapse. Not all neurotransmitters released into the synapse are used, so an unused neurotransmitter is reabsorbed and recycled in a process called reuptake. Medications influence neurotransmitter systems to treat mental disorders. Medications may block synapses to decrease neurotransmitter levels or block reuptake to increase neurotransmitter levels. People with depression often take drugs such as Prozac or Paxil to increase availability of certain neurotransmitters for improved energy and mood. Six major neurotransmitters are discussed throughout this textbook: serotonin, norepinephrine, dopamine, gamma-aminobutyric acid (GABA), acetylcholine, and glutamate. Table 2.1 lists functions associated with each. Brain The brain is our most complex and important organ and comprises about 86 billion neurons (Lent, Azevedo, Andrade-Moraes, & Pinto, 2012). The brain consists of two cerebral hemispheres that are mirror images of each other. The right hemisphere controls movement for the left side of the body, influences spatial relations and patterns, and affects emotion and intuition. The left hemisphere controls movement for the right side of the body, in uences analytical thinking, and affects grammar and
FIGURE 2.3 BASIC PARTS OF A NEURON. Adapted from Josephine F.
ReplyDeleteWilson, Biological foundations of human behavior, Fig. 2.6, p. 30. Reprinted
by permission of the author