Schizophrenia

Schizophrenia

Clinical Symptoms of Schizophrenia

  • Definition:
    Schizophrenia is a psychotic disorder characterized by major disturbances in thought, emotion, and behavior.
      - Disordered thinking where ideas are not logically related.
      - Faulty perception and attention.
      - Flat or inappropriate affect.
      - Bizarre disturbances in motor activity.

Prevalence

  • Prevalence in Canada:
      - Median 12-month prevalence: 0.33%
      - Median lifetime prevalence: 0.48%
      - Usually appears in late adolescence or early adulthood.
      - Appears earlier for men than for women.
      - Almost half are treated in the community.
      - Almost 50% commit suicide.
      - 18% suffer from a comorbid disorder, which can include:
        - Personality disorders (e.g., avoidant, paranoid, dependent).
        - Substance use disorders (e.g., alcohol, cannabis).
        - Mood disorders (e.g., major depressive disorder, anxiety).

  • Meta-Analysis Findings (Goldner, Hsu, Waraich, & Somers, 2002):
      - Real variation in schizophrenia across geographical regions.
      - Higher rates in psychotic disorders among immigrants from the Caribbean and Bermuda.
      - Specific populations have the lowest prevalence rates.
      - Symptoms like auditory and visual hallucinations are significantly higher among individuals from certain nations (Bauer et al., 2011).
      - India shows better recovery rates, especially in Southern India due to various social factors.

Remission in Schizophrenia

  • Remission Rates:
      - Vary widely across studies.
      - Slightly more than 35.6% experience symptom remission in first-episode schizophrenia.
      - 37.0% in multiple episode schizophrenia.
      - Factors associated with remission include:
        - Milder initial symptoms.
        - Better premorbid functioning.
        - Earlier treatment response.
        - Shorter duration of untreated psychosis.

Symptoms in Schizophrenia

  • Disturbances in:
      - Thought.
      - Perception.
      - Attention.
      - Motor behavior.
      - Affect.
      - Life functioning.

  • People with schizophrenia demonstrate greater variability compared to those with other disorders.

Positive Symptoms

  • Definition: Excess of behaviors not seen in most people.

  • Includes:
      - Disorganized Speech (Word Salad):
        - Speech is incoherent with difficulty in maintaining an organized thought process.
        - Not always evident in diagnosis, as this symptom overlaps with other psychoses (Andreasen, 1979).
        - Examples include loose associations or derailment where the speaker drifts from one topic to another.
      - Delusions:
        - False beliefs held contrary to reality.
        - Most common delusions include persecutory delusions (65%).
          - Individuals may feel their thoughts are broadcasted or controlled by external forces.
      - Hallucinations:
        - Sensory experiences without external stimuli.
          - Auditory hallucinations are more common (74% in studied populations – Sartorius et al., 1974).
          - Hallucinations may include hearing voices arguing or commenting on one's behavior.

Negative Symptoms

  • Definition: Absence of behaviors typical in most people.

  • Includes:
      - Avolition (Apathy): A lack of motivation in daily activities, grooming, and socialization.
        - May result in attention deficit towards personal care; a 10-year longitudinal study identifies this as a predictor of poorer life functioning (Evensen et al., 2012).
      - Alogia:
        - Refers to poverty of speech; thought disorder leading to reduced fluency and amount of speech.
        - Although discourse may be adequate, it lacks substantial information and can be repetitive.
      - Anhedonia:
        - Inability to experience pleasure in activities once enjoyed, including social relationships and sexual activities.
      - Flat Affect:
        - Minimal emotional expression; vacuously vacant facial expressions and toneless speech observed.
        - Lacked expressiveness compared to non-schizophrenics in response to emotional stimuli (Kring and Neale, 1996).
      - Asociality:
        - Severe impairment in social relationships; few friends and poor social skills evident, often noted as childhood social troubles.

Other Symptoms

  • Motor Abnormalities:
      - Odd gestures and movements, motor overactivity akin to mania, or catatonic immobility.
      - Catatonia can include bizarre postures maintained for long durations and waxy flexibility.

  • Inappropriate Affect:
      - Rapid emotional shifts with responses seemingly unsuitable to circumstances (e.g., laughing upon hearing of a death).

The Impact of Symptoms on Life

  • Distress: Delusions and hallucinations lead to significant distress, contributing to shattered hopes and dreams.

  • Cognitive Impairments and Avolition: Difficulties in maintaining stable employment due to cognitive impairments.

  • Social Implications:
      - High rates of substance abuse as an escape from negative emotions (Blanchard et al., 1999).
      - A high suicide rate amongst those diagnosed with schizophrenia.

History of the Concept of Schizophrenia

  • Emil Kraepelin and Eugen Bleuler:
      - Kraepelin first introduced ‘dementia praecox,’ while Bleuler coined ‘schizophrenia,’ deriving from Greek terms meaning 'to split mind'.
      - Kraepelin's focus on early onset and progressive deterioration led to differentiating between different types of psychoses.
      - Bleuler introduced the notion of schizophrenia emphasizing a broader spectrum of symptoms and disputing Kraepelin's views on inevitable decline.

DSM Diagnosis of Schizophrenia

  • DSM-IV-TR Classifications:
      - Three initial subtypes:
        - Disorganized (Hebephrenic).
        - Catatonic.
        - Paranoid.

  • Contemporary DSM-5 Approach:
      - Discontinued subtypes in favor of dimensional ratings of symptoms.
      - Despite issues with previous systems, differentiation remains of interest, focusing on neurocognitive features relating to brain abnormalities.

Etiology of Schizophrenia

Genetic Factors

  • Family Studies: Evidence suggests heritable risk, with closer genetic relationships showing increased susceptibility.

  • Twin Studies: MZ twins show a concordance rate of 44.3%, while DZ twins are at 12.08%.

  • Adoption Studies: Children born to mothers with schizophrenia face increased risk, independent of environmental factors.

  • Molecular Genetics: Multiple genes are implicated, potentially contributing to several psychiatric disorders, with various disruptions identified (e.g., DACGR2 in the 22q11.2 microdeletion area).

Biochemical Factors

  • Dopamine Hypothesis: Suggests schizophrenia arises from dopamine overactivity, supported by antipsychotic efficacy.

  • Other Neurotransmitters: Investigations into serotonin and glutamate reveal regulatory roles on dopamine pathways; low glutamate levels have been reported among affected individuals (Faustman et al., 1999).

Brain Structure and Function

  • Structural Changes: Enlarged ventricles observed through CT/MRI scans may reflect brain cell loss.

  • Functional Impairment: Prefrontal cortex functioning is disrupted, linking cognitive deficits with behavioral symptoms. Twin studies indicate abnormalities are not strictly genetic, hinting at environmental contributions.

Developmental Considerations

  • Congenital Damage: Birth complications can increase risk factors for developing schizophrenia.

  • Fetal Exposure: Intrauterine infections and poor maternal nutrition correlate with increased risks in later life, citing specific examples of the influenza virus.

Psychological Stress Factors

  • Psychological stress is implicated in exacerbating symptoms or triggering relapses (Hirsch et al., 1996).

  • Social Class Impact: Higher incidences of schizophrenia are correlated with lower socioeconomic status (Tandon et al., 2008).

The Family Influence

  • Stressful family environments may increase risk and facilitate relapses (expressed emotion - EE) through critical interactions (Masland & Hooley, 2015).

  • Analysis of atypical comments within high-EE households shows a bi-directional relationship in symptom exacerbation.

Therapies for Schizophrenia

Biological Treatments

  1. First-generation Antipsychotics:
       - Reduce positive symptoms (~30-50% effective).
       - Common side effects include extrapyramidal symptoms: tremors, rigidity, akathisia, and tardive dyskinesia (10-20% affected).

  2. Second-generation Antipsychotics:
       - More effective with fewer side effects (e.g., clozapine, risperidone).
       - Impact on serotonin in addition to dopamine, beneficial in reducing both positive and negative symptoms.

Psychosocial Treatments

  • Includes social skills training, cognitive-behavioral therapy, and family interventions to enhance social functioning and mitigate symptoms.

  • The integration of psychological and biological approaches shows improved outcomes in reducing relapse rates and enhancing treatment efficacy.