1. Cognitive disorders and the assessment of brain damage (p. 459) Cognitive disorders are behavioral disturbances that result from transient or permanent damage to the brain and affect thinking, memory, consciousness, and perception and are affected by social and psychological factors, such as coping ability and stress. DSM-IV-TR differentiates delirium, dementia, amnestic disorders, and other cognitive disorders. Although exact diagnosis is typically a process of elimination, overall prevalence of cognitive disorders is about 1 percent for severe disorders and 6 percent for mild disorders, with people 75 years old having twenty-two times the rate of such disorders as those between 18 and 34. There is no gender difference, but African Americans have higher rates of severe cognitive disorders than whites or Hispanic Americans.
   Brain damage can be assessed through neuropsychological testing and neurological tests. The first uses behavioral responses from the patient on memory or manual dexterity tasks. The second directly monitors the brain through electroencephalography (EEG), computerized axial tomography (CAT) scans, positron emission tomography (PET), magnetic resonance imaging (MRI), and dynamic functional magnetic resonance imaging (fMRI). Each has its strengths and weaknesses.
2. Localization and the dimensions of brain damage (p. 463) Neurological techniques can locate brain damage; however, there is extensive overlapping of functions in the brain, which complicates assessment. Localization is also complicated by diaschisis, where lesions in one area disrupt other intact areas, and by recovery of function after damage, which can occur because of redundancy or plasticity in the brain. Brain damage ranges from mild to severe, and can be distinguished as exogenous (caused by external factors) or endogenous (something within the person), diffuse or specific, acute or chronic.
3. Diagnostic problems (p. 465) People without brain damage can be misdiagnosed as having a cognitive disorder. This is particularly likely for those suffering from severe depression, or someone with a head injury who is desirous of making money through litigation or compensation and is thus motivated to show impairment on neurological tests. The elderly are also vulnerable to misdiagnosis. Most older persons who function well may nonetheless score in the brain-damaged range on neuropsychological tests. The opposite is also true: those with brain damage may be misdiagnosed as having a psychological disorder. For this reason, follow-up testing at regular intervals is often recommended.
4. Types of cognitive disorders (p. 466) Within each of the four types of cognitive disorders, clinicians categorize according to cause, such as psychoactive substance-induced or general medical condition. The most prominent features of dementia are memory impairment and cognitive disturbance, including language disturbance (aphasia, impairments in motor activities (apraxia), misidentification of faces or objects (agnosia), and problems with planning and abstractions. These impairments hinder social and occupational life. The onset of dementia is usually gradual and is often caused by general medical conditions (especially Alzheimer's disease), substance abuse, combinations of the two, or dementia not otherwise specified. About 1.5 million Americans suffer from severe dementia, and 1 to 5 million have mild to moderate forms. It affects about 5-7 percent of people over age 65 (2-4 percent have Alzheimers); prevalence increases with age: over 20 percent of people over age 85 suffer from dementia.
   Delirium involves impairments in consciousness and changes in cognition (disorientation, incoherent speech, perceptual distortions), and it usually develops rapidly. Amnestic disorders entail an inability to retain new information or recall old information, or both, and may be caused by head trauma, stroke, Wernickes encephalopathy which is an alcohol-induced thiamine deficiency). While the three conditions have overlapping symptoms, dementias are usually accompanied by language problems such as aphasia and come on gradually (as opposed to delirium). Memory loss is the primary symptom of amnestic disorders.
5. Etiology of cognitive disorders: Brain trauma (p. 469) Brain traumaa physical wound tot he brain-is one cause of cognitive disorders. Head injuries include concussions, when blood vessels are damaged by a blow to the head; contusions, when blood vessels rupture because of the brains impact against the skull; and lacerations, when tissue is tom or pierced by an object penetrating the skull. More than eight million Americans suffer head injuries each year, and 20 percent of these result in serious head trauma. Personality changes as well as cognitive and motor impairments are common. Only one-third of closed-head injury patients return to gainful employment after traditional rehabilitation. New treatments for head-injury survivors, including intensive cognitive retraining, increased awareness of the injury and its consequences, and compensatory skills training, hold promise.
6. Aging and disorders associate with aging (p. 471) The aging population of the United States is growing, due both to longer life expectancy and the large number of baby boomers.
   Stroke, the third major cause of death in the United States, is a common cognitive disorder in the elderly. Strokes (cerebrovascular accidents) occur when blood flow to an area of the brain is cut off, causing a loss of brain function. Only 50 to 60 percent of stroke victims survive, and they require long-term care. At least 25 percent of stroke victims develop major depression. Causes of stroke include bursting of blood vessels and narrowing or blockage of blood vessels owing to the buildup of fatty material on interior walls (atherosclerosis), which results in cerebral infarction (death of the brain cells results). A series of small strokes is known as vascular dementia; it is characterized by uneven deterioration of physical and intellectual abilities. Risk factors include hypertension, heart disease, cigarette smoking, diabetes, and excessive alcohol consumption.
   Memory loss in the elderly may be due to brain cell deterioration, vascular dementia, and the normal aging process. A common cause is intoxication from prescribed medications. To assess age-related cognitive deficits, the individuals performance can be compared with general population norms, age-group norms, norms based on similarity in status or education, and the persons previous functioning.
7. Alzheimers disease (p. 474) Alzheimers disease, involving atrophy of cortical tissue, leads to intellectual and emotional deterioration, including memory loss, irritability, and social withdrawal. Death usually occurs within five years. Alzheimers is the fourth leading cause of death in the United States. The likelihood of developing Alzheimers increases with age, affecting about 8 to 15 percent of those over 65. Autopsies show neurofibrillary tangles and senile plaques in the brains of people with the disease. The causes of Alzheimers are unknown, but heredity may play a role in some subtypes; infection, head injury, exposure to aluminum, and reduced neurotransmitter levels may be related to others. The gene that appears to be associated with plaques and tangles is located on chromosome 21. Protective factors include genetic endowment with the ApoE-e2 allele; higher education, use of non-steroidal anti-inflammatories or estrogen replacement, and vitamin E.
8. Other diseases and infections of the brain (p. 477) Parkinsons disease has the following symptoms: muscle tremors; a stiff, shuffling gait; and an expressionless face. The disorder is associated with lesions in the motor area of the brain stem and insufficient dopamine levels. Treatment is generally L-dopa or a similar drug.
   The majority of AIDS patients also suffer from some form of dementia. It is not clear whether the AIIDS virus affects the brain, AIDS-related infections cause neuropsychological problems, or depression and anxiety about having AIDS cause cognitive symptoms.
   Neurosyphilis (general paresis) is brain damage caused by the delayed effect of a syphilis infection. It occurs in about 10 percent of syphilis cases. Symptoms include memory impairment, delusions, paralysis, and death within five years.
   Encephalitis (sleeping sickness) is a viral infection of the brain that produces long periods of sleep followed by agitation and seizures.
   Meningitis, an inflammation of the membrane around the brain, can be caused by bacteria, viruses, or fungi, and has a wide range of effects and potential residual disturbances.
   Huntingtons disease is a genetically transmitted disorder that first shows in early middle age. Symptoms begin with twitches and progress to uncontrollable jerking movements, irritability, and confusion. Death comes within thirteen to sixteen years after onset. A gene has been identified that causes the disorder. It is frequently misdiagnosed as schizophrenia.
9. Cerebral tumors (p. 480) A cerebral tumor is a mass of abnormal tissue growing in the brain. Fast-growing tumors in the brain produce severe mental symptoms, such as diminished attention, drowsiness, dementia, and mood changes, or may be severe enough to result in coma. Removal of tumors can result in dramatic improvement of functioning.
10. Epilepsy (p. 480) Epilepsy is a set of symptoms, not a disorder. It involves brief periods of altered consciousness, often accompanied by seizures. About 2.5 million children and adults in the United States have epilepsy or some other seizure disorder. The most common neurological problem, epilepsy is most often diagnosed during childhood. Causes are genetic a well as environmental. Although epilepsy cannot be cured, it can be controlled with medication.
    Tonic-clonic seizures are most dramatic and include four stages: an aura (a signal before seizures), the tonic phase (the person becomes unconscious and falls to the ground), the clonic phase (convulsions), and a coma (exhaustion; the muscles relax) after the seizures are over. Causes ranging from tumors to illness to stress can account for epilepsy. Heredity may not be a necessary condition for onset; no personality type is associated with epilepsy.
11. Etiology of cognitive disorders: Psychoactive substances (p. 482) Substances can cause cognitive disorders by having effects on the nervous system. The most common substances involved include alcohol, amphetamines, cocaine, PCP, hallucinogens, and opiates.
12. Treatment considerations (p. 482) Treatment approaches include medical strategies such as surgery and medication (for the disorder itself or to control emotional problems accompanying the disorder), and psychological efforts such as skills acquisition, cognitive preparation, application training, and psychotherapy, such as behavior modification and biofeedback.
    How family and friends can assist those with cognitive disorders is an important issue. Some suggestions are preserving a sense of independence and control, maintaining interpersonal contacts that do not overwhelm, engaging in pleasant diversions, providing tasks that increase self-worth, and ensuring that caregivers obtain social support for themselves.
13. Mental retardation (p. 484) Mental retardation is diagnosed on Axis II of DSM-IV-TR; it is not actually considered a cognitive disorder, although cognitive abilities are affected. Until recently, people with mental retardation were considered incapable of benefiting from schooling and were institutionalized. It is now estimated that about 75 percent of people with mental retardation, if given appropriate training, can be completely self-supporting. About 7 million people in the United States are mentally retarded, based on IQ scores below 70 and deficiencies in adaptive behavior that are diagnosed before age 18. IQ scores are particularly problematic with Hispanic and African Americans. While some argue that genetics explain lower IQ scores among African Americans, others point to the disadvantages African Americans face cultural biases in the IQ tests, and psychological maladjustments such as low self-esteem. The DSM-IV-TR uses levels of retardation based on Wechsler IQ scores to categorize mental retardation into four types: Mild (IQ 50-55 to 70); Moderate (IQ 35-40 to 50-55); Severe (IQ 20-25 to 35-40); and Profound (IQ under 20). The American Association on Mental Retardation uses the individual's need for support as a way of subdividing retardation, but uses an IQ score cutoff of 75, not 70.
    Environmental factors such as poor nutrition and substandard school or home environments are associated with retardation. Genetics may account for the low end of intelligence where appearance and health are normal. Genetic abnormalities result in severe forms of retardation such as Fragile X Syndrome or Down syndrome, whose characteristics include short stature, slanted eyes, and protruding tongue. There is an association between increasing age of the mother and higher risk of having a Down syndrome baby. Down syndrome stems from having an extra chromosome (trisomy 21), something that can be identified during pregnancy through amniocentesis or even earlier with chorionic villus sampling. People with Down syndrome who live past 40 are at risk for developing Alzheimers (having a common flaw on chromosome 21). Less common genetic anomalies (e.g., Tay-Sachs disease, Klinefelters syndrome, etc.) can also cause mental retardation.
    Retardation can be caused by environmental mishaps before birth (prenatal), during birth (perinatal), or after birth (postnatal). Important prenatal causes are infections during pregnancy and fetal alcohol syndrome, which causes small body and brain size and may cause retardation and hyperactivity. Important perinatal factors are prematurity, low birth weight, and trauma. Postnatal causes, which seem to be on the rise, include head injury sustained in auto accidents or in child abuse.
    Programs such as Head Start have had positive long-term, if not dramatic, results. High-risk children in such programs show improved school performance compared to control children, and families are positively influenced as well. People with mental handicaps can achieve more than was once imagined. More and more people with mental retardation are living in the least restrictive environment. Nontraditional group living arrangements can be helpful if they teach living skills.