When the Brain Dies FirstCamara PowellPeriod 1, Anatomy & PhysiologyFebruary 2012

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

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

Biological BasesEvidence 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

Most Common DisordersSchizophrenia

Depression

Dissociative Identity Disorder (MPD)

Phobias

Mood Disorders (Bi-polar, etc.)

Anxiety

Compulsions

SchizophreniaLiteral 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, apathyNegative symptoms are less influenced by

medications than positive symptoms

Genetic Influences on Schizophrenia

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

The Depression Cycle

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.

PhobiasSpecific 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?

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

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

Mood DisordersManic 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

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

PET Scan of Bipolar Brain