Lecture Notes on Schizophrenia

Introduction to Schizophrenia

• Definition: Schizophrenia is derived from "schizo" (split) and "phrenia" (mind).
• Often misunderstood as split personality; in reality, it’s characterized by fragmented thinking.
• Syndrome: A collection of symptoms that vary among individuals.

Symptoms of Schizophrenia

Three Major Categories:

1. Positive Symptoms

   • Do not refer to helpful traits; indicate new features without a physiological counter.
   • Types:
     • Delusions: False beliefs resistant to contrary evidence.
       • E.g., delusion of control (belief others control actions), delusion of reference (insignificant remarks are directed at them).
     • Hallucinations: Sensations without external stimuli (auditory, visual).
     • Disorganized Speech: Random jumble of words (e.g., "pencil dog hat coffee blue").
     • Disorganized Behavior: Bizarre, purposeless actions (e.g., inappropriate clothing for weather).
     • Catatonic Behavior: Extreme resistance to movement or unresponsive stupor.

2. Negative Symptoms

   • Involve reduction or removal of normal functions.
   • Types:
     • Flat Affect: Lack of emotional response.
     • Alogia: Poverty of speech (limited content).
     • Avolition: Decreased motivation to achieve goals.

3. Cognitive Symptoms

   • Difficulties in memory, learning, and understanding.
   • Often subtle and detected through specific tests (e.g., trouble tracking multiple pieces of information).

Phases of Schizophrenia

1. Prodromal Phase: Withdrawal, similar to depression/anxiety.
2. Active Phase: Severe symptoms (delusions, hallucinations, disorganized behavior).
3. Residual Phase: Return to cognitive symptoms and withdrawal.

Diagnosis Criteria

• Must have two of the following, one being from the positive symptoms:
  1. Delusions
  2. Hallucinations
  3. Disorganized Speech
  4. Disorganized Behavior or Catatonic Behavior
  5. Negative Symptoms
• Disturbances must last at least 6 months with one month of active symptoms.
• Symptoms must not be due to another condition (e.g., substance abuse).

Causes of Schizophrenia

• Unknown: Unique to humans; hard to model in animals.
• Dopamine Hypothesis: Many antipsychotics block D2 receptors, suggesting dopamine may play a role.
• Limitations: Medications aren't universally effective; other systems like norepinephrine, serotonin, and GABA may be involved.
• Genetic Factors: Twin studies indicate a genetic basis; no specific genes conclusively linked.
• Environmental Factors: Prenatal infections and autoimmune disorders are linked to schizophrenia.
• Epidemiology: More common in men, onset in mid-twenties; women have later onset and less severe symptoms (potential link to estrogen).
• No significant racial differences.

Treatment of Schizophrenia

• Challenges: Treatment is complex; requires a multidisciplinary approach.
• Antipsychotic Medications: Can reduce symptoms but have considerations such as cost and potential side effects (tolerance, dependence, withdrawal).
• Importance of therapy and counseling alongside medication.