{"id":568,"date":"2024-03-11T11:18:51","date_gmt":"2024-03-11T15:18:51","guid":{"rendered":"https:\/\/opentextbc.ca\/psychologymtdi\/chapter\/psychological-disorders-chapter-resources\/"},"modified":"2024-10-24T11:57:43","modified_gmt":"2024-10-24T15:57:43","slug":"psychological-disorders-chapter-resources","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/psychologymtdi\/chapter\/psychological-disorders-chapter-resources\/","title":{"raw":"Chapter Resources","rendered":"Chapter Resources"},"content":{"raw":"

Summary<\/h1>\r\n

What Are Psychological Disorders?<\/span><\/h2>\r\n

Psychological disorders are conditions characterised by abnormal thoughts, feelings, and behaviours. Although challenging, it is essential for psychologists and mental health professionals to agree on what kinds of inner experiences and behaviours constitute the presence of a psychological disorder. Inner experiences and behaviours that are atypical or violate social norms could signify the presence of a disorder; however, each of these criteria alone is inadequate. Harmful dysfunction describes the view that psychological disorders result from the inability of an internal mechanism to perform its natural function. Many of the features of harmful dysfunction conceptualisation have been incorporated in the APA\u2019s formal definition of psychological disorders. According to this definition, the presence of a psychological disorder is signalled by significant disturbances in thoughts, feelings, and behaviours; these disturbances must reflect some kind of dysfunction (biological, psychological, or developmental), must cause significant impairment in one\u2019s life, and must not reflect culturally expected reactions to certain life events.<\/p>\r\n\r\n

Diagnosing and Classifying Psychological Disorders<\/span><\/h2>\r\n

The diagnosis and classification of psychological disorders is essential in studying and treating psychopathology. The classification system used by most US professionals is the DSM-5. The first edition of the DSM was published in 1952 and has undergone numerous revisions. The 5th and most recent edition, the DSM-5, was published in 2013. The diagnostic manual includes a total of 237 specific diagnosable disorders, each described in detail, including its symptoms, prevalence, risk factors, and comorbidity. Over time, the number of diagnosable conditions listed in the DSM has grown steadily, prompting criticism from some. Nevertheless, the diagnostic criteria in the DSM are more explicit than that of any other system, which makes the DSM system highly desirable for both clinical diagnosis and research.<\/p>\r\n\r\n

Perspectives on Psychological Disorders<\/span><\/h2>\r\n

Psychopathology is very complex, involving a plethora of etiological theories and perspectives. For centuries, psychological disorders were viewed primarily from a supernatural perspective and thought to arise from divine forces or possession by spirits. Some cultures continue to hold this supernatural belief. Today, many who study psychopathology view mental illness from a biological perspective, whereby psychological disorders are thought to result largely from faulty biological processes. Indeed, scientific advances over the last several decades have provided a better understanding of the genetic, neurological, hormonal, and biochemical bases of psychopathology. The psychological perspective, in contrast, emphasises the importance of psychological factors (e.g., stress and thoughts) and environmental factors in the development of psychological disorders. A contemporary, promising approach is to view disorders as originating from an integration of biological and psychosocial factors. The diathesis-stress model suggests that people with an underlying diathesis, or vulnerability, for a psychological disorder are more likely than those without the diathesis to develop the disorder when faced with stressful events.<\/p>\r\n\r\n

Neurodevelopmental <\/span>Disorders<\/span><\/h2>\r\n

Neurodevelopmental disorders are a group of disorders that are typically diagnosed during childhood and characterised by developmental deficits in personal, social, academic, and intellectual realms. These disorders include attention deficit\/hyperactivity disorder (ADHD) and autism spectrum disorder. ADHD is characterised by a pervasive pattern of inattention and\/or hyperactive and impulsive behaviour that interferes with normal functioning. Genetic and neurobiological factors contribute to the development of ADHD, which can persist well into adulthood and is often associated with poor long-term outcomes. The major features of autism spectrum disorder include deficits in social interaction and communication and repetitive movements or interests. As with ADHD, genetic factors appear to play a prominent role in the development of autism spectrum disorder; exposure to environmental pollutants such as mercury have also been linked to the development of this disorder. Although it is believed by some that autism is triggered by the MMR vaccination, evidence does not support this claim.<\/p>\r\n\r\n

Schizophrenia<\/span><\/h2>\r\n

Schizophrenia is a severe disorder characterised by a complete breakdown in one\u2019s ability to function in life; it often requires hospitalisation. People with schizophrenia experience hallucinations and delusions and have extreme difficulty regulating their emotions and behaviour. Thinking is incoherent and disorganised, behaviour is extremely bizarre, emotions are flat, and motivation to engage in most basic life activities is lacking. Considerable evidence shows that genetic factors play a central role in schizophrenia; however, adoption studies have highlighted the additional importance of environmental factors. Neurotransmitter and brain abnormalities, which may be linked to environmental factors such as obstetric complications or exposure to influenza during the gestational period, have also been implicated. A promising new area of schizophrenia research involves identifying individuals who show prodromal symptoms and following them over time to determine which factors best predict the development of schizophrenia. Future research may enable us to pinpoint those especially at risk for developing schizophrenia and who may benefit from early intervention.<\/span><\/p>\r\n\r\n

Mood Disorders<\/span><\/h2>\r\n

Mood disorders are those in which the person experiences severe disturbances in mood and emotion. They include depressive disorders and bipolar and related disorders. Depressive disorders include major depressive disorder, which is characterised by episodes of profound sadness and loss of interest or pleasure in usual activities and other associated features, and persistent depressive disorder, which is marked by a chronic state of sadness. Bipolar disorder is characterised by mood states that vacillate between sadness and euphoria; a diagnosis of bipolar disorder requires experiencing at least one manic episode, which is defined as a period of extreme euphoria, irritability, and increased activity. Mood disorders appear to have a genetic component, with genetic factors playing a more prominent role in bipolar disorder than in depression. Both biological and psychological factors are important in the development of depression.<\/p>\r\n\r\n

Anxiety Disorders<\/span><\/h2>\r\n

Anxiety disorders are a group of disorders in which a person experiences excessive, persistent, and distressing fear and anxiety that interferes with normal functioning. Anxiety disorders include: a specific phobia (unrealistic fear); social anxiety disorder (extreme fear and avoidance of social situations); panic disorder (being suddenly overwhelmed by panic even though there is no apparent reason to be frightened); agoraphobia (an intense fear and avoidance of situations in which it might be difficult to escape); and generalised anxiety disorder (a relatively continuous state of tension, apprehension, and dread).<\/p>\r\n\r\n

Obsessive-Compulsive and Related Disorders<\/span><\/h2>\r\n

Obsessive-compulsive and related disorders are a group of DSM-5 disorders that overlap somewhat in that they each involve intrusive thoughts and\/or repetitive behaviours. Perhaps the most recognised of these disorders is obsessive-compulsive disorder, in which a person is obsessed with unwanted, unpleasant thoughts and\/or compulsively engages in repetitive behaviours or mental acts, perhaps as a way of coping with the obsessions. Body dysmorphic disorder is characterised by the individual becoming excessively preoccupied with one or more perceived flaws in his physical appearance that are either nonexistent or unnoticeable to others. Preoccupation with the perceived physical defects causes the person to experience significant anxiety regarding how he appears to others. Hoarding disorder is characterised by persistent difficulty in discarding or parting with objects, regardless of their actual value, often resulting in the accumulation of items that clutter and congest the person's living area.<\/p>\r\n\r\n

Posttraumatic Stress Disorder<\/span><\/h2>\r\n

Posttraumatic stress disorder (PTSD) was described through much of the 20th century and was referred to as shell shock and combat neurosis in the belief that its symptoms were thought to emerge from the stress of active combat. Today, PTSD is defined as a disorder in which the experience of a traumatic or profoundly stressful event, such as combat, sexual assault, or natural disaster, produces a constellation of symptoms that must last for one month or more. These symptoms include intrusive and distressing memories of the event, flashbacks, avoidance of stimuli or situations that are connected to the event, persistently negative emotional states, feeling detached from others, irritability, proneness toward outbursts, and a tendency to be easily startled. Not everyone who experiences a traumatic event will develop PTSD; a variety of risk factors associated with its development have been identified.<\/p>\r\n\r\n

Dissociative Disorders<\/span><\/h2>\r\n

The main characteristic of dissociative disorders is that people become dissociated from their sense of self, resulting in memory and identity disturbances. Dissociative disorders listed in the DSM-5 include dissociative amnesia, depersonalisation\/derealisation disorder, and dissociative identity disorder. A person with dissociative amnesia is unable to recall important personal information, often after a stressful or traumatic experience.<\/p>\r\n

Depersonalisation\/derealisation disorder is characterised by recurring episodes of depersonalisation (i.e., detachment from or unfamiliarity with the self) and\/or derealisation (i.e., detachment from or unfamiliarity with the world). A person with dissociative identity disorder exhibits two or more well-defined and distinct personalities or identities, as well as memory gaps for the time during which another identity was present.<\/p>\r\n

Dissociative identity disorder has generated controversy, mainly because some believe its symptoms can be faked by patients if presenting its symptoms somehow benefits the patient in avoiding negative consequences or taking responsibility for one\u2019s actions. The diagnostic rates of this disorder have increased dramatically following its portrayal in popular culture. However, many people legitimately suffer over the course of a lifetime with this disorder.<\/p>\r\n\r\n

Personality Disorders<\/span><\/h2>\r\n

Individuals with personality disorders exhibit a personality style that is inflexible, causes distress and impairment, and creates problems for themselves and others. The DSM-5 recognises 10 personality disorders, organised into three clusters. The disorders in Cluster A include those characterised by a personality style that is odd and eccentric. Cluster B includes personality disorders characterised chiefly by a personality style that is impulsive, dramatic, highly emotional, and erratic, and those in Cluster C are characterised by a nervous and fearful personality style. Two Cluster B personality disorders, borderline personality disorder and antisocial personality disorder, are especially problematic. People with borderline personality disorder show marked instability in mood, behaviour, and self-image, as well as impulsivity. They cannot stand to be alone, are unpredictable, have a history of stormy relationships, and frequently display intense and inappropriate anger. Genetic factors and adverse childhood experiences (e.g., sexual abuse) appear to be important in its development. People with antisocial personality display a lack of regard for the rights of others; they are impulsive, deceitful, irresponsible, and unburdened by any sense of guilt. Genetic factors and socialisation both appear to be important in the origin of antisocial personality disorder. Research has also shown that those with this disorder do not experience emotions the way most other people do.<\/p>\r\n\r\n

Review Questions<\/h1>\r\n
\r\n

Multiple Choice Questions<\/h2>\r\n<\/header>\r\n
\r\n
    \r\n \t
  1. In the harmful dysfunction definition of psychological disorders, dysfunction involves ________.\r\n
      \r\n \t
    1. the inability of an psychological mechanism to perform its function<\/li>\r\n \t
    2. the breakdown of social order in one\u2019s community<\/li>\r\n \t
    3. communication problems in one\u2019s immediate family<\/li>\r\n \t
    4. all the above<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
    5. Patterns of inner experience and behaviour are thought to reflect the presence of a psychological disorder if they ________.\r\n
        \r\n \t
      1. are highly atypical<\/li>\r\n \t
      2. lead to significant distress and impairment in one\u2019s life<\/li>\r\n \t
      3. embarrass one\u2019s friends and\/or family<\/li>\r\n \t
      4. violate the norms of one\u2019s culture<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
      5. The letters in the abbreviation DSM-5 stand for ________.\r\n
          \r\n \t
        1. Diseases and Statistics Manual of Medicine<\/li>\r\n \t
        2. Diagnosable Standards Manual of Mental Disorders<\/li>\r\n \t
        3. Diseases and Symptoms Manual of Mental Disorders<\/li>\r\n \t
        4. Diagnostic and Statistical Manual of Mental Disorders.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
        5. A study based on over 9,000 US residents found that the most prevalent disorder was ________.\r\n
            \r\n \t
          1. major depressive disorder<\/li>\r\n \t
          2. social anxiety disorder<\/li>\r\n \t
          3. obsessive-compulsive disorder<\/li>\r\n \t
          4. specific phobia<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
          5. The diathesis-stress model presumes that psychopathology results from ________.\r\n
              \r\n \t
            1. vulnerability and adverse experiences<\/li>\r\n \t
            2. biochemical factors<\/li>\r\n \t
            3. chemical imbalances and structural abnormalities in the brain<\/li>\r\n \t
            4. adverse childhood experiences<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
            5. Dr. Anastasia believes that major depressive disorder is caused by an over-secretion of cortisol. Dr. Anastasia's view on the cause of major depressive disorder reflects a ________ perspective.\r\n
                \r\n \t
              1. psychological<\/li>\r\n \t
              2. supernatural<\/li>\r\n \t
              3. biological<\/li>\r\n \t
              4. diathesis-stress<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
              5. In which of the following anxiety disorders is the person in a continuous state of excessive, pointless worry and apprehension?\r\n
                  \r\n \t
                1. panic disorder<\/li>\r\n \t
                2. generalised anxiety disorder<\/li>\r\n \t
                3. agoraphobia<\/li>\r\n \t
                4. social anxiety disorder<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                5. Which of the following would constitute a safety behaviour?\r\n
                    \r\n \t
                  1. encountering a phobic stimulus in the company of other people<\/li>\r\n \t
                  2. avoiding a field where snakes are likely to be present<\/li>\r\n \t
                  3. avoiding eye contact<\/li>\r\n \t
                  4. worrying as a distraction from painful memories<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                  5. Which of the following best illustrates a compulsion?\r\n
                      \r\n \t
                    1. mentally counting backward from 1,000<\/li>\r\n \t
                    2. persistent fear of germs<\/li>\r\n \t
                    3. thoughts of harming a neighbour<\/li>\r\n \t
                    4. falsely believing that a spouse has been cheating<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                    5. Research indicates that the symptoms of OCD ________.\r\n
                        \r\n \t
                      1. are similar to the symptoms of panic disorder<\/li>\r\n \t
                      2. are triggered by low levels of stress hormones<\/li>\r\n \t
                      3. are related to hyperactivity in the orbitofrontal cortex<\/li>\r\n \t
                      4. are reduced if people are asked to view photos of stimuli that trigger the symptoms<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                      5. Symptoms of PTSD include all of the following except ________.\r\n
                          \r\n \t
                        1. intrusive thoughts or memories of a traumatic event<\/li>\r\n \t
                        2. avoidance of things that remind one of a traumatic event<\/li>\r\n \t
                        3. jumpiness<\/li>\r\n \t
                        4. physical complaints that cannot be explained medically<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                        5. Which of the following elevates the risk for developing PTSD?\r\n
                            \r\n \t
                          1. severity of the trauma<\/li>\r\n \t
                          2. frequency of the trauma<\/li>\r\n \t
                          3. high levels of intelligence<\/li>\r\n \t
                          4. social support<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                          5. Common symptoms of major depressive disorder include all of the following except ________.\r\n
                              \r\n \t
                            1. periods of extreme elation and euphoria<\/li>\r\n \t
                            2. difficulty concentrating and making decisions<\/li>\r\n \t
                            3. loss of interest or pleasure in usual activities<\/li>\r\n \t
                            4. psychomotor agitation and retardation<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                            5. Clifford falsely believes that the police have planted secret cameras in his home to monitor their every movement. Clifford\u2019s belief is an example of ________.\r\n
                                \r\n \t
                              1. a delusion<\/li>\r\n \t
                              2. a hallucination<\/li>\r\n \t
                              3. tangentiality<\/li>\r\n \t
                              4. a negative symptom<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                              5. A study of adoptees whose biological mothers had schizophrenia found that the adoptees were most likely to develop schizophrenia ________.\r\n
                                  \r\n \t
                                1. if their childhood friends later developed schizophrenia<\/li>\r\n \t
                                2. if they abused drugs during adolescence<\/li>\r\n \t
                                3. if they were raised in a disturbed adoptive home environment<\/li>\r\n \t
                                4. regardless of whether they were raised in a healthy or disturbed home environment<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                5. Dissociative amnesia involves ________.\r\n
                                    \r\n \t
                                  1. memory loss following head trauma<\/li>\r\n \t
                                  2. memory loss following stress<\/li>\r\n \t
                                  3. feeling detached from the self<\/li>\r\n \t
                                  4. feeling detached from the world<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                  5. Dissociative identity disorder mainly involves ________.\r\n
                                      \r\n \t
                                    1. depersonalisation<\/li>\r\n \t
                                    2. derealisation<\/li>\r\n \t
                                    3. schizophrenia<\/li>\r\n \t
                                    4. different personalities<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                    5. Which of the following is not a primary characteristic of ADHD?\r\n
                                        \r\n \t
                                      1. short attention span<\/li>\r\n \t
                                      2. difficulty concentrating and distractibility<\/li>\r\n \t
                                      3. restricted and fixated interest<\/li>\r\n \t
                                      4. excessive fidgeting and squirming<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                      5. One of the primary characteristics of autism spectrum disorder is ________.\r\n
                                          \r\n \t
                                        1. bed-wetting<\/li>\r\n \t
                                        2. difficulty relating to others<\/li>\r\n \t
                                        3. short attention span<\/li>\r\n \t
                                        4. intense and inappropriate interest in others<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                        5. People with borderline personality disorder often ________.\r\n
                                            \r\n \t
                                          1. try to be the centre of attention<\/li>\r\n \t
                                          2. are shy and withdrawn<\/li>\r\n \t
                                          3. are impulsive and unpredictable<\/li>\r\n \t
                                          4. tend to accomplish goals through cruelty<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t
                                          5. Antisocial personality disorder is associated with ________.\r\n
                                              \r\n \t
                                            1. emotional deficits<\/li>\r\n \t
                                            2. memory deficits<\/li>\r\n \t
                                            3. parental overprotection<\/li>\r\n \t
                                            4. increased empathy<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
                                              \r\n

                                              Critical Thinking Questions<\/h2>\r\n<\/header>\r\n
                                              \r\n
                                                \r\n \t
                                              1. Discuss why thoughts, feelings, or behaviours that are merely atypical or unusual would not necessarily signify the presence of a psychological disorder. Provide an example.<\/li>\r\n \t
                                              2. Describe the DSM-5. What is it, what kind of information does it contain, and why is it important to the study and treatment of psychological disorders?<\/li>\r\n \t
                                              3. The International Classification of Diseases (ICD) and the DSM differ in various ways. What are some of the differences in these two classification systems?<\/li>\r\n \t
                                              4. Why is the perspective one uses in explaining a psychological disorder important?<\/li>\r\n \t
                                              5. Describe how cognitive theories of the etiology of anxiety disorders differ from learning theories.<\/li>\r\n \t
                                              6. Discuss the common elements of each of the three disorders covered in this section: obsessive-compulsive disorder, body dysmorphic disorder, and hoarding disorder.<\/li>\r\n \t
                                              7. List some of the risk factors associated with the development of PTSD following a traumatic event.<\/li>\r\n \t
                                              8. Why is research following individuals who show prodromal symptoms of schizophrenia so important?<\/li>\r\n \t
                                              9. The prevalence of most psychological disorders has increased since the 1980s. However, as discussed in this section, scientific publications regarding dissociative amnesia peaked in the mid-1990s but then declined steeply through 2003. In addition, no fictional or nonfictional description of individuals showing dissociative amnesia following a trauma exists prior to 1800. How would you explain this phenomenon?<\/li>\r\n \t
                                              10. Compare the factors that are important in the development of ADHD with those that are important in the development of autism spectrum disorder.<\/li>\r\n \t
                                              11. Imagine that a child has a genetic vulnerability to antisocial personality disorder. How might this child\u2019s environment shape the likelihood of developing this personality disorder?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
                                                \r\n

                                                Personal Application Questions<\/h2>\r\n<\/header>\r\n
                                                \r\n
                                                  \r\n \t
                                                1. Identify a behaviour that is considered unusual or abnormal in your own culture; however, it would be considered normal and expected in another culture.<\/li>\r\n \t
                                                2. Even today, some believe that certain occurrences have supernatural causes. Think of an event, recent or historical, for which others have provided a supernatural explanation.<\/li>\r\n \t
                                                3. Think of someone you know who seems to have a tendency to make negative, self-defeating explanations for negative life events. How might this tendency lead to future problems? What steps do you think could be taken to change this thinking style?<\/li>\r\n \t
                                                4. Try to find an example (via a search engine) of a past instance in which a person committed a horrible crime, was apprehended, and later claimed to have dissociative identity disorder during the trial. What was the outcome? Was the person revealed to be faking? If so, how was this determined?<\/li>\r\n \t
                                                5. Discuss the characteristics of autism spectrum disorder with a few of your friends or members of your family (choose friends or family members who know little about the disorder) and ask them if they think the cause is due to bad parenting or vaccinations. If they indicate that they believe either one to be true, why do you think this might be the case? What would be your response?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n

                                                  Review Questions Answers<\/h2>\r\n

                                                  Multiple Choice Question Answers<\/h3>\r\n
                                                    \r\n \t
                                                  1. A<\/li>\r\n \t
                                                  2. B<\/li>\r\n \t
                                                  3. D<\/li>\r\n \t
                                                  4. A<\/li>\r\n \t
                                                  5. A<\/li>\r\n \t
                                                  6. C<\/li>\r\n \t
                                                  7. B<\/li>\r\n \t
                                                  8. C<\/li>\r\n \t
                                                  9. A<\/li>\r\n \t
                                                  10. C<\/li>\r\n \t
                                                  11. D<\/li>\r\n \t
                                                  12. A<\/li>\r\n \t
                                                  13. A<\/li>\r\n \t
                                                  14. A<\/li>\r\n \t
                                                  15. C<\/li>\r\n \t
                                                  16. B<\/li>\r\n \t
                                                  17. D<\/li>\r\n \t
                                                  18. C<\/li>\r\n \t
                                                  19. B<\/li>\r\n \t
                                                  20. C<\/li>\r\n \t
                                                  21. A<\/li>\r\n<\/ol>\r\n

                                                    Critical Thinking Question Answers<\/h3>\r\n
                                                      \r\n \t
                                                    1. Just because something is atypical or unusual does not mean it is disordered. A person may experience atypical inner experiences or exhibit unusual behaviours, but she would not be considered disordered if they are not distressing, disturbing, or reflecting a dysfunction. For example, a classmate might stay up all night studying before exams; although atypical, this behaviour is unlikely to possess any of the other criteria for psychological disorder mentioned previously.<\/li>\r\n \t
                                                    2. The DSM-5 is the classification system of psychological disorders preferred by most US mental health professionals, and it is published by the American Psychiatric Association (APA). It consists of broad categories of disorders and specific disorders that fall within each category. Each disorder has an explicit description of its symptoms, as well as information concerning prevalence, risk factors, and comorbidity. The DSM-5 provides a common language that enables mental health professionals to communicate effectively about sets of symptoms.<\/li>\r\n \t
                                                    3. The ICD is used primarily for making clinical diagnoses and more broadly for examining the general health of populations and monitoring the international prevalence of diseases and other health problems. While the DSM is also used for diagnostic purposes, it is also highly valued as a research tool. For example, much of the data regarding the etiology and treatment of psychological disorders are based on diagnostic criteria set forth in the DSM.<\/li>\r\n \t
                                                    4. The perspective one uses in explaining a psychological disorder consists of assumptions that will guide how to best study and understand the nature of a disorder, including its causes, and how to most effectively treat the disorder.<\/li>\r\n \t
                                                    5. Learning theories suggest that some anxiety disorders, especially specific phobia, can develop through a number of learning mechanisms. These mechanisms can include classical and operant conditioning, modelling, or vicarious learning. Cognitive theories, in contrast, assume that some anxiety disorders, especially panic disorder, develop through cognitive misinterpretations of anxiety and other symptoms.<\/li>\r\n \t
                                                    6. Each of the three disorders is characterised by repetitive thoughts and urges, as well as an uncontrollable need to engage in repetitive behaviour and mental acts. For example, repetitive thoughts include concerns about contamination (OCD), imagined physical defects (body dysmorphic disorder), and discarding one\u2019s possessions (hoarding disorder). Uncontrollable needs to engage in repetitive behaviours and mental acts include persistent handwashing (OCD), constantly looking in the mirror (body dysmorphic disorder) and engaging in efforts to acquire new possessions (hoarding disorder).<\/li>\r\n \t
                                                    7. Risk factors associated with PTSD include gender (female), low socioeconomic status, low intelligence, personal and family history of mental illness, and childhood abuse or trauma. Personality factors, including neuroticism and somatisation, may also serve as risk factors. Also, certain versions of a gene that regulates serotonin may constitute a diathesis.<\/li>\r\n \t
                                                    8. This kind of research is important because it enables investigators to identify potential warning signs that predict the onset of schizophrenia. Once such factors are identified, interventions may be developed.<\/li>\r\n \t
                                                    9. Several explanations are possible. One explanation is that perhaps there is little scientific interest in this phenomenon, maybe because it has yet to gain consistent scientific acceptance. Another possible explanation is that perhaps dissociative amnesia was fashionable at the time publications dealing with this topic peaked (1990s) and since that time it has become less fashionable.<\/li>\r\n \t
                                                    10. Genetic factors appear to play a major role in the development of both ADHD and autism spectrum disorder; studies show higher rates of concordance among identical twins than among fraternal twins for both disorders. In ADHD, genes that regulate dopamine have been implicated; in autism spectrum disorder, de novo genetic mutations appear to be important. Imaging studies suggest that abnormalities in the frontal lobes may be important in the development of ADHD. Parenting practices are not connected to the development of either disorder. Although environmental toxins are generally unimportant in the development of ADHD, exposure to cigarette smoke during the prenatal period has been linked to the development of the disorder. A number of environmental factors are thought to be associated with an increased risk for autism spectrum disorder: exposure to pollutants, an urban versus rural residence, and vitamin D deficiency. Although some people continue to believe that MMR vaccinations can cause autism spectrum disorder (due to an influential paper that was later retracted), there is no scientific evidence that supports this assertion.<\/li>\r\n \t
                                                    11. The environment is likely to be very instrumental in determining the likelihood of developing antisocial personality disorder. Research has shown that adverse family environments (e.g., divorce or marital problems, legal problems, and drug use) are connected to antisocial personality disorder, particularly if one is genetically vulnerable. Beyond one\u2019s family environment, peer group delinquency and community variables (e.g., economic deprivation, community disorganisation, drug use, and the presence of adult antisocial models) heighten the risk of violent behaviour.<\/li>\r\n<\/ol>\r\n

                                                      Key Terms<\/h1>\r\n
                                                      \r\n

                                                      Key Terms<\/p>\r\n\r\n<\/header>\r\n

                                                      \r\n