Schizophrenia

• Delusion


  A false belief
• Hallucination


  A sensory perception that has no basis in external reality
• Delusions are different from hallucinations in that delusions are false beliefs while hallucinations are false sensory perceptions
• Disorganized thoughts


  Thoughts or speech that are jumbled and don't make sense
• Catatonic behavior


  When a person is unmoving and unresponsive to their environment, or exhibits repetitive movements
• Negative symptoms


  A loss or reduction of normal functioning, such as reduced speech or lack of facial expression
• Positive symptoms of schizophrenia are delusions, hallucinations, disorganized thoughts, and catatonic behavior
• Schizophrenia is on a spectrum, with symptoms varying in duration and severity
• Disorders on the schizophrenia spectrum

  • Schizotypal personality disorder
  • Delusional disorder
  • Brief psychotic disorder
  • Schizophreniform disorder
  • Schizophrenia
  • Schizoaffective disorder
  • Substance/medication-induced psychotic disorder
  • Psychotic disorder due to another medical condition
  • Catatonia associated with another mental disorder
  • Unspecified schizophrenia spectrum and other psychotic disorders
• Delusional disorder


  Persistent false beliefs without other symptoms like hallucinations or disorganized thoughts
• Types of delusional disorder

  • Erotomanic
  • Grandiose
  • Jealous
  • Persecutory
  • Somatic
• Bizarre delusion


  An extremely strange and implausible belief
• Non-bizarre delusion


  A false belief that is more plausible, like believing a partner is cheating
• Delusional beliefs


  • Believing Captain America is in love with you (erotomanic)
  • Believing the police are chasing you (persecutory)
  • Believing you are the Queen of England (grandiose)
• There was a virtual reality study by Freeman to understand the persecutory beliefs of people with schizophrenia
• The challenge in diagnosing schizophrenia is that some social behaviors may be misinterpreted as symptoms, when they are just cultural differences
• Schizophrenia


  A mental disorder characterized by a break from reality, including hallucinations and delusions
• Challenges in diagnosing schizophrenia

  • Social interactions may be misinterpreted as symptoms
  • Patients may not be truthful in clinical settings
• Using virtual reality to diagnose schizophrenia

  1. Standardize the environment

  2. Use neutral avatars

  3. Measure paranoid and persecutory thinking
• The study used 200 non-clinical students, not actual schizophrenic patients
• The study found that students with higher paranoid and persecutory thinking had stronger reactions to neutral avatar behaviors
• Explanations for schizophrenia


  • Genetic
  • Biochemical
  • Cognitive
• Endophenotypes


  Genetic markers that may be inherited and contribute to schizophrenia
• Twin studies showed that monozygotic twins (who share more genetic material) are more likely to both have schizophrenia compared to dizygotic twins
• Dopamine hypothesis


  Schizophrenia is linked to excess dopamine activity in certain brain regions
• Brain scans of schizophrenic patients show more dopamine receptors in some areas and less in the prefrontal cortex
• Cognitive approach


  Explains schizophrenia as a result of faulty mental processes and abnormalities in self-monitoring
• Schizophrenic patients may misattribute their own thoughts and actions to external sources
• Hallucinations in schizophrenia can be explained as a failure to recognize one's own internal speech
• People with schizophrenia often have abnormality of self-monitoring, where they don't realize they are the ones saying things to themselves and think there is another voice in their head
• Hallucinations can be explained from a cognitive perspective, where the brain is too active and misrepresents or misperceives things as real
• Delusions


  False perceptions, where someone misrepresents their perception of reality
• Paranoia


  Misrepresenting the intentions of others, thinking they have something against you
• Negative symptoms


  Loss of self-awareness, leading to lack of facial expression or catatonic behavior
• Treatments for schizophrenia


  • Biochemical (medication)
  • ECT (electroconvulsive therapy)
  • Token economy (behavioral conditioning)
  • CBT (cognitive behavioral therapy)
• Typical antipsychotics


  First generation drugs like chlorpromazine and haloperidol, used to treat psychotic disorders
• Atypical antipsychotics


  Second generation drugs like clozapine and risperidone, with fewer negative side effects
• How antipsychotic drugs work

  1. Block dopamine and serotonin receptors to reduce brain activity

  2. Reduce positive symptoms like hallucinations and delusions within 2-3 weeks
• Double-blind placebo study


  Patients and administrators don't know who gets the real drug vs placebo, to test effectiveness
• About 50% of patients show significant improvement with antipsychotic drugs, 30-40% show partial improvement, and a small minority show no improvement (treatment resistant schizophrenia)