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