Schizophrenia and Psychotic Disorders Review

Chapter 11: Schizophrenia (and other Psychotic Disorders)

Categories of Symptoms in Schizophrenia

Positive Symptoms

  • Hallucinations: Incorrect perceptions without external stimuli.
      - Auditory: Hearing voices or sounds that are not present.
      - Visual: Seeing things that are not there.
      - Tactile: Feeling sensations on the skin that have no physical cause.
      - Olfactory: Smelling odors that don't exist.
      - Gustatory: Tasting things that are not in the mouth.

  • Delusions: Strongly held false beliefs despite contradictory evidence.
      - Persecution: Belief that one is being targeted or harassed.
      - Thought insertion: Belief that thoughts are being placed in one’s mind by an external force.
      - Thought broadcasting: Belief that one’s thoughts are accessible to others.
      - Grandiose: Exaggerated sense of self-importance.
      - Ideas of reference: Belief that common elements of the environment are directly related to oneself.

  • Disorganized Speech: Incoherent or nonsensical speech patterns, often reflecting disrupted thought processes.

  • Disorganized Behavior: Behavior that is inappropriate or ineffective in a given situation or context.

  • Catatonia: Marked by unusual movements or immobility, which can include waxy flexibility.

Negative Symptoms

  • Flat/Blunted Affect: Reduced emotional expression.

  • Alogia/Poverty of Speech: Limited speech output, reflecting a lack of thought.

  • Avolition: A decrease in motivation to initiate or sustain activities.

  • Asociality: Lack of interest in social interactions.

  • Anhedonia: Inability to experience pleasure from activities typically found enjoyable.

Schizophrenia: Diagnostic Criteria

  • Diagnosis requires the presence of two or more of the following symptoms, each for a significant time during a one-month period:
      1. Delusions
      2. Hallucinations
      3. Disorganized Speech
      4. Disorganized or Catatonic Behavior
      5. Negative Symptoms

  • Functioning: Must show a decreased level of functioning in one or more major areas, such as:
      - Work
      - Interpersonal relations
      - Self-care

  • Duration: Continuous signs must persist for at least six months, including at least one month of the first three symptoms listed. If symptoms remitted with treatment, the six-month period can be less.

  • Differential Diagnosis: Other disorders must be ruled out to ensure an accurate diagnosis.

Other Related Disorders

  • Schizoaffective Disorder: Hybrid symptoms of mood disorder and psychosis.

  • Schizophreniform Disorder: Symptoms similar to schizophrenia lasting between 1 and 6 months.

  • Brief Psychotic Disorder: Symptoms lasting less than 1 month.

  • Delusional Disorder: Characterized by delusions lasting for at least 1 month.

Demographics

  • Gender and Age:
      - Schizophrenia appears at equal rates in men and women across a lifetime.
      - Onset varies: earlier onset in men compared to women, with women showing fewer negative symptoms and often a better prognosis.

  • Socioeconomic Class: Notable increases in schizophrenia prevalence exist among the poorest populations.

Biological Predisposing Factors

  • Genetic Factors:
      - Higher concordance rates in monozygotic (MZ) twins compared to dizygotic (DZ) twins, indicating a genetic component.
      - Adoption studies support a polygenic model.

  • Environmental Influences:
      - Extreme stress during the second trimester of pregnancy and exposure to viruses may contribute.
      - A correlation exists between being born in winter or spring and increased risk of developing schizophrenia.

Brain Abnormalities in Schizophrenia

  • Enlarged Ventricles: Indicative of brain structural changes.

  • Prefrontal Cortex:
      - Decreased volume and activation, associated with cognitive deficits.

Neurotransmitter Abnormalities in Schizophrenia: Dopamine Theory

  • Accidental Discovery: The anti-psychotic effects of neuroleptic drugs lead to questions regarding the role of dopamine.

  • Negative Symptoms: Neuroleptics are ineffective against negative symptoms, indicating complexity in dopamine function.

  • Differential Receptor Functioning: Decreased functioning of dopamine receptors (D1) noted in the prefrontal cortex.

Complexity of Dopamine Functioning in Schizophrenia

  • Dual Pathways Theory:
      - It is not simply 'too much' or 'too little' dopamine; instead, multiple pathways exist with some having excessive dopamine and others deficient.

Glutamate Dysfunction in Schizophrenia

  • Role of Glutamate:
      - Glutamate receptors influence other neurotransmitter systems, including dopamine.
      - Research indicates decreased glutamate activity in the brains of individuals with schizophrenia, suggesting a multifactorial pathology.

Pharmacological Intervention

  • Neuroleptics/Antipsychotics: Common medications used to manage symptoms.
      - Side Effects: Include dry mouth, sedation, sexual dysfunction, and movement disorders.

  • Atypical/Second Generation Antipsychotics:
      - Tend to have different side effects, including weight gain and risk of diabetes.

Cognitive Components

  • Attentional Processes: Impairments noted even in non-schizophrenic relatives, indicating potential genetic or environmental contributions.

  • Cognitive Intervention:
      - Cognitive restructuring applied for mild delusions.
      - Cognitive rehabilitation targeting attention, memory, and verbal skills for affected individuals.

Other Interventions

  • Social Skills Training: Focus on enhancing interpersonal abilities.

  • Psychoeducation: Involves educating patients and families about the disorder.

  • Family Counseling: Support and resources for families impacted by schizophrenia.