Schizophrenia Lecture Notes

Schizophrenia

  • Present in humans throughout history.
  • Affects approximately 1 in 100 people worldwide.
  • About 3.2 million Americans currently have the disorder.
  • Appears in all socioeconomic groups but is more frequent in lower levels.
  • Downward Drift Theory: Schizophrenia causes a fall from higher to lower social levels.
  • Equal numbers of men and women are diagnosed.
  • In men, symptoms begin earlier (average age of onset = 23 years) and are more severe compared to women (average age of onset = 28 years).

Symptoms of Schizophrenia

  • Symptoms are grouped into three categories:
    • Positive symptoms
    • Negative symptoms
    • Psychomotor symptoms

Positive Symptoms of Schizophrenia

  • Positive symptoms: "Pathological excesses" or bizarre additions to a person’s behavior.
    • Delusions: Faulty interpretations of reality.
      • Content varies: being controlled by others, persecution, reference (special messages), grandeur (perceived special powers).
    • Disordered thinking and speech (thought disorder).
      • May include loose associations, neologisms (made-up words), perseverations, and clang.
    • Heightened perceptions: Senses are being flooded.
    • Hallucinations: Sensory perceptions that occur in the absence of external stimuli.
      • Most common are auditory hallucinations.
      • Other senses: tactile, somatic, visual, gustatory, or olfactory.
    • Inappropriate affect: Emotions that are unsuited to the situation.

Negative Symptoms of Schizophrenia

  • Negative symptoms: "Pathological deficits" or characteristics lacking in an individual.
    • Poverty of speech (alogia):
      • Long lapses before responding to questions or failure to answer.
      • Reduction of quantity of speech or speech content.
    • Blunted and flat affect: Show less emotion than most people, face is expressionless, avoidance of eye contact.
    • Loss of volition: Apathy, lack of motivation or directedness.
    • Social withdrawal

Psychomotor Symptoms of Schizophrenia

  • Psychomotor symptoms: Awkward movements, repeated grimaces, odd gestures.
  • The movements seem to have a ritual quality.
  • These symptoms may take extreme forms, collectively called catatonia.
    • Includes stupor, rigidity, posturing, and excitement.

Course of Schizophrenia

  • Usually first appears between the late teens and mid-30s.
  • Three phases:
    • Prodromal: Beginning of deterioration; mild symptoms.
    • Active: Symptoms become increasingly apparent.
    • Residual: A return to prodromal levels.
  • Each phase of the disorder may last for days or years.
  • One-quarter of patients fully recover; three-quarters continue to have residual problems.
  • Better prognosis (fuller recovery) is more likely in people:
    • With high premorbid functioning (how the person was functioning before the onset of the illness).
    • Whose disorder was triggered by stress.
    • With abrupt onset.
    • With later onset (during middle age).
    • Those who receive treatment.

Diagnosing Schizophrenia

  • The DSM calls for a diagnosis only after signs of the disorder continue for six months or more.
  • Must include a period of a month or more of active symptoms: delusions, hallucinations, and/or thought disorder.
  • People must also show a deterioration in their work, social relations, and ability to care for themselves.

Type 1 and Type 2 Schizophrenia

  • Type I schizophrenia: Dominated by positive symptoms.
    • Seem to have better adjustment before the disorder, later onset of symptoms, and greater likelihood of improvement.
    • May be linked more closely to biochemical abnormalities in the brain.
    • Seen in 80-85% of cases.
  • Type II schizophrenia: Dominated by negative symptoms.
    • May be tied largely to structural abnormalities in the brain.

Schizophrenia Spectrum Disorders

  • Brief psychotic disorder
  • Schizophreniform disorder
  • Schizoaffective psychosis
  • Delusional disorder
  • Psychotic disorder due to another medical condition
  • Substance/medication-induced psychotic disorder

Explaining Schizophrenia

  • Research has focused on:
    • Biological factors (most promising)
    • Psychological factors
    • Sociocultural factors

Biological Views of Schizophrenia

  • Genetic factors:
    • Schizophrenia is more common among relatives of people with the disorder.
      • General population: 1%
      • Second-degree relatives: 3%
      • First-degree relatives: 10%
    • The closer the biological relationship, the greater the risk of developing the disorder.
    • Twin studies and Adoption studies

Dopamine Hypothesis

  • Biochemical abnormalities:
    • Over the past 4 decades, researchers have developed the dopamine hypothesis:
      • Certain neurons using dopamine fire too often, producing symptoms of schizophrenia.
    • This theory is based on the effectiveness of antipsychotic medications (dopamine antagonists).

Evidence Supporting Dopamine Hypothesis

  • Patients with Parkinson’s develop schizophrenic symptoms if they take too much L-dopa, a medication that raises dopamine levels.
  • People who take high doses of amphetamines, which increase dopamine activity in the brain, may develop amphetamine psychosis – a syndrome similar to schizophrenia.
  • Investigators have also located the dopamine receptors to which antipsychotic drugs bind, preventing further neuron firing.
  • Messages traveling from dopamine-sending neurons to dopamine-receptors (particularly D-2) may be transmitted too easily or too often.

Challenges to the Dopamine Hypothesis

  • Discovery of a new type of antipsychotic drug (“atypical” antipsychotics) now called “second-generation antipsychotic drugs”.
    • More effective than traditional antipsychotics
    • Bind to D-2 dopamine receptors and many D-1 receptors, and to other neurotransmitters (serotonin, glutamate, & GABA) receptors
    • Therefore, schizophrenia may be related to abnormal activity or interactions of both dopamine and other neurotransmitters.
  • Dysfunctional brain structures and circuitry:
    • Researchers have also linked schizophrenia to a dysfunctional brain circuit.
    • This circuit includes the prefrontal cortex, hippocampus, amygdala, thalamus, striatum, and substantia nigra, among other structures.

Viral Problems

  • A growing number of researchers suggest that the biochemical and structural brain abnormalities seen in schizophrenia result from exposure to viruses before birth.
  • Some of the evidence comes from animal model investigations.

Psychodynamic Explanation

  • Fromm-Reichmann: Schizophrenogenic mothers
    • Elaboration on Freudian view; little research support & has been rejected by most psychodynamic theorists

Cognitive-Behavioral Explanations

  • Operant conditioning—focus on reinforcement: Circumstantial support; more recently viewed as a partial explanation.
  • Misinterpreting unusual sensations: No direct research support.

Sociocultural Views

  • Sociocultural theorists believe that three main social forces contribute to schizophrenia:
    • Multicultural factors
    • Social labeling
    • Family dysfunction
  • Although these forces are considered important in the development of schizophrenia, research has not yet clarified what their precise relationships might be.

Multicultural Factors

  • Rates of the disorder differ by ethnicity and race.
  • Ex: African Americans are more likely than non-Hispanic white Americans to receive this diagnosis and are overrepresented in mental hospitals.
    • More prone to biased diagnoses
    • Misread cultural differences
    • Economic hardship effects

Social Labeling

  • Many sociocultural theorists believe that the features of schizophrenia are influenced by the diagnosis itself.
  • Society labels people who fail to conform to certain norms of behavior.
  • Once assigned, the label becomes a self-fulfilling prophecy.

Family Dysfunctioning

  • One of the best-known family theories of schizophrenia is the double-bind hypothesis:
    • Some parents repeatedly communicate mutually contradictory messages that place the child in so-called double-bind situations; the child cannot avoid displeasing the parents because nothing the child does is right.
  • Schizophrenia linked to family stress:
    • Parents often:
      • Display more conflict
      • Have greater difficulty communicating
      • Are more critical of and overinvolved with their children
    • High “expressed emotion” – family members frequently express criticism and hostility and intrude on each other’s privacy.

Developmental Psychopathology View

  • Applies an integrative and developmental framework
  • Individual’s genetic predisposition is implemented by a dysfunctional brain circuit
  • May lead to schizophrenia if he/she experiences significant life stressors, difficult family interactions, and/or other negative environmental factors

Developmental Psychopathology—Developing Schizophrenia

  • Genetically-based Brain Circuit Dysfunction
  • Overreactive HPA Axis
  • Chronic Brain Inflammation
  • Social Withdrawal
  • Substantial Life Stress
  • MULTIFINALITY