Unit 9 Schizophrenia, Affective Disorders, and Anxiety Disorders INTRODUCTION Many factors can cause the brain to malfunction, including trauma, drugs, toxins, hypoxia, stress, and genetic abnormalities. In previous units, we have seen some examples of what can happen when the brain malfunctions, including learning disorders, communication disorders, drug addiction, and more. In this unit, we will look at other possible problems that can arise from brain dysfunction, including mood disorders, schizophrenia, and anxiety disorders. We will focus on the possible causes of mental illness, the associated structural, physiological, and biochemical abnormalities, and possible corrective or ameliorative treatments. Perhaps, no human ailments are more personally devastating than those involving malfunctions of the brain. Our brains are the repositories of our thoughts, ideas, beliefs, emotions, hopes, dreams, and identities.
Because the brain holds the sum of what makes us uniquely human, brain disorders can rob us of our humanity. As we have seen throughout this course, damage to the brain can produce highly variable results, depending on the location and magnitude of the injury. Disturbances can run the gamut from simple motor ticks to language impairments, cognitive deficits, personality changes, and complete physical and mental incapacitation.
Unfortunately, although a great deal of work has been done on recovery from brain injury, there is yet much progress to be made. Even so, as it now stands, the prognosis remains poor for certain disorders. To understand why this is so, pay close attention to the potential mechanisms of recovery from brain injury and develop a firm understanding of the factors that influence the speed and extent of rehabilitation.
The phrases mental illness and mental disease describe another kind of brain disorder that can be as devastating as those due to functional deficits. Whereas a specific brain injury can often be pinpointed as the cause of neuropsychological impairment, the causes of mental illness tend to be multifactorial and far more difficult to identify (Carlson, 2014). In cases involving heritable disorders, it is often possible to establish a genetic link that clarifies the etiology, or causation. Even then, environmental and other factors such as injury or communicable disease may contribute. Initial causation aside, chemical imbalances in the brain appear to play a part in most forms of mental illness.
Schizophrenia, one of the most devastating of all mental illnesses, takes many forms and can occur with various degrees of severity. Schizophrenia consists of positive symptoms, the presence of unusual behavior, and negative symptoms, the absence of normal behavior (Carlson, 2014). Because it has a heritable, or genetic, component, we know that it has a biological basis, and it is believed that many of its most debilitating symptoms result from faulty neurotransmission.
However, because not all individuals with a genetic predisposition for schizophrenia actually develop the disease, we know that environmental factors contribute to its emergence. The prevalent etiological theory of schizophrenia, called the dopamine hypothesis (Carlson, 2014), posits that its positive symptoms are caused by excessive dopamine neurotransmission. Evaluate this hypothesis in the course of your readings, paying close attention to its evolution over the years. Consider its implications for treatment, particularly in light of the newer atypical neuroleptic drugs now being used to treat schizophrenia.
There are two principal types of major affective (mood) disorders, bipolar and unipolar (Carlson, 2014). Bipolar disorder is characterized by cyclical episodes of mania and depression, while unipolar disorder involves depression alone. Although bipolar disorder is far from rare, unipolar disorder (chronic depression) is much more common, affecting millions of people and constituting one of the most prevalent forms of mental illness. Research shows that both of these disorders are associated with distinctive brain anomalies, have heritable components, and respond to pharmacological intervention as well as psychotherapy. Because patients suffering from mood disorders have been found to respond positively to sleep deprivation, disruption of REM sleep, and exposure to sunlight, it is clear that these disorders are somehow linked to biological rhythms.
There are four major anxiety disorders that you will learn about in this unit: panic disorder, generalized anxiety disorder, obsessive-compulsive disorder and social anxiety disorder. The commonality among these four disorders is that they are characterized by unrealistic, unfounded fear and anxiety. Nearly a quarter of people will experience an anxiety disorder at some point in their lives, making these the most common psychiatric illnesses. References Carlson, N. R. (2014). Foundations of behavioral neuroscience (9th ed.). Boston, MA: Pearson. OBJECTIVES To successfully complete this learning unit, you will be expected to: 1.) Analyze the role that biological factors (genes, brain chemistry) play in the development of schizophrenia. 2.) Analyze the biological foundation of anxiety and depression. 3.) Understand the interconnectivity between physiological psychology, culture, and psychological disorders. Studies Readings
Read the following: Carlson, N. R. (2014). Foundations of behavioral neuroscience (9th ed.). Boston, MA: Pearson. ISBN: 9780205940240. Chapter 15, “Schizophrenia, Affective Disorders, and Anxiety Disorders,” pages 389–415, in your course text. Lammel, S., Tye, K. M., & Warden, M. R. (2014). Progress in understanding mood disorders: Optogenetic dissection of neural circuits. Genes, Brain & Behavior, 13(1), 38–51. Yu, Y., Shen, H., Zeng, L., Ma, Q., & Hu, D. (2013). Convergent and divergent functional connectivity patterns in schizophrenia and depression. PLOS ONE, 8(7), 1–11. Grupe, D. W., & Nitschke, J. B. (2013). Uncertainty and anticipation in anxiety: An integrated neurobiological and psychological perspective. Nature Reviews Neuroscience, 14(7), 488–501. Russo, S. J., & Nestler, E. J. (2013). The brain reward circuitry in mood disorders. Nature Reviews Neuroscience, 14(9), 609–625.
***ASSIGNMENT***
Schizophrenia For this discussion: Locate and read a recent, full-text article from the Capella library that examines how schizophrenia relates to genetics or brain chemistry. Contrast the positive and negative symptoms of schizophrenia and explain why it is thought these different symptoms might have a different physiological foundation. Discuss any cultural aspects involved in working with and providing treatment to a client with schizophrenia. Cite your source using standard APA guidelines.
