When the Brain Dies First


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When the Brain Dies First

  1. 1. When the Brain Dies FirstCamara PowellPeriod 1, Anatomy & PhysiologyFebruary 2012
  2. 2. Definition of a Neurological Disorder The DSM-IV proposed definition of a mental disorder is as follows:  A behavioral or psychological syndrome or pattern that occurs in an individual  That reflects an underlying psychobiological dysfunction  The consequences of which are clinically significant distress (e.g., a painful symptom) or disability (i.e., impairment in one or more important areas of functioning)  That is not primarily a result of social deviance or conflicts with society
  3. 3. Environmental Impact Identical twins don’t show 100% concordance, so there must be an environmental component Stress triggers potential risk and can make it worse, however the severity of impact is difficult to measure Persons born in winter are more likely to develop post- natal mental illness in Northern climates In years of influenza epidemics, babies born 3 months later are at increased risk for mental illness (diagnosed 20 years later) Pre-natal development is highly influential, and can be detrimental
  4. 4. Biological Bases Evidence from several case studies via the following methods concludes that most neurological disorders are a result of highly active synapses within the brain:  Brain scans  Studies using antipsychotic drugs  Drugs decreasing dopamine activity in brain reduce severity  Drugs increasing dopamine in brain (e.g., L-dopa) can produce schizophrenic-like conditions  Dopamine Hypothesis: Underlying cause of neurological disorders is excessive stimulation of certain types of dopamine synapses
  5. 5. Most Common Disorders  Schizophrenia  Depression  Dissociative Identity Disorder (MPD)  Phobias  Mood Disorders (Bi-polar, etc.)  Anxiety  Compulsions
  6. 6. Schizophrenia Literal translation: “split mind”  Subtypes: Paranoid, Disorganized, Catatonic, Indifferent  Symptoms include disorders of thought (e.g., delusions & paranoia). language (e.g., incoherence, rhyming speech), perception (e.g., auditory hallucinations – 70% of schizophrenics report hearing voices), blunted or inappropriate emotions, and/or strange or odd behaviors (e.g., facial grimaces)  Typically caused by either genetic, biological, environmental, or developmental abnormalities  Positive neurology: Hallucinations, delusions  Negative neurology: Isolation, withdrawal, apathy  Negative symptoms are less influenced by medications than positive symptoms
  7. 7. Genetic Influences on Schizophrenia
  8. 8. Depression “Common cold” of mental illness  17% lifetime prevalence  Twice as common among women as men  Bias in diagnosis? Characteristics: Persistent sadness, gloom, hopelessness, guilt, worthlessness, decreased energy, marked changes in sleeping/eating, difficulty concentrating, restlessness Environmental factors  ¾ of recently depressed individuals experienced a preceding negative life event. However, only 1 in 5 experiencing a negative life event develop depression Cognitive features  Negative view of themselves, the world, and the future (cognitive triad)  Attention turned inward (rather than outward) Important Risk factors  Low social support, low self-esteem, ruminative response style, physical/emotional illness, previous episode of depression, heredity
  9. 9. The Depression Cycle
  10. 10. Dissociative Identity Disorder Formerly called Multiple Personality Disorder  The presence of 2 or more distinct identities or personality states that recurrently take control of behavior  Each personality has its own memories, behavior patterns and social relations  Misconception: schizophrenia = having multiple personalities  Identities may have contrasting personalities which may emerge in certain circumstances and may differ in reported age and gender, vocabulary use, general attitude and predominant affect  Time to switch between identities is usually only a matter of seconds and often accompanied by visible changes.
  11. 11. Phobias  Specific phobia types in DSM-IV  Animal type (snakes, spiders)  Natural environment type (heights, storms)  Blood-injection-injury (BII) type (seeing blood, getting a shot, watching surgery)  Situational type (enclosed spaces, bridges)  Other (vomiting, loud sounds, clowns, being constantly watched by a duck) Thought experiment: What are your three biggest fears?
  12. 12. Adaptations to Predators & Environmental Dangers Fears: Snakes, spiders, heights, separation, darkness, strangers Responses: Freeze, flee, fight, submit Developmental timing of onset of fears: Coincides with adaptive problems
  13. 13. List of Common Phobias:  Myrmecophobia- Ants  Phalacrophobia- Becoming bald  Hobophobia- Bums or beggars  Acrophobia- Heights  Pentheraphobia- Mother-in-law  Hypengyophobia- Responsibility  Venustraphobia- Beautiful women  Ailurophobia- Cats  Gamophobia- Marriage  Ophidiophobia- Snakes  Arachnophobia- Spiders  Hydrophobia- Water
  14. 14. Mood Disorders Manic Depression  Characterized by dramatic mood swings—from overly "high" and/or irritable to sad and hopeless, and then back again, often with periods of normal mood in between  Depressive episode: usual symptoms of depression  Manic episode  Increasing rates of teen suicide 1% prevalence Approximately 1 in 5 die from suicide Highly heritable  70% concordance rate for MZ twins, 20% for DZ
  15. 15. Bipolar Disorder "Manic-depression distorts moods and thoughts, incites dreadful behaviors, destroys the basis of rational thought, and too often erodes the desire and will to live. It is an illness that is biological in its origins, yet one that feels psychological in the experience of it; an illness that is unique in conferring advantage and pleasure, yet one that brings in its wake almost unendurable suffering and, not infrequently, suicide. “ -- Kay Redfield Jamison, Ph.D., An Unquiet Mind, 1995
  16. 16. PET Scan of Bipolar Brain