Week 2 Flashcards
Childhood Videotaped Social and Neuromotor Precursors of Schizophrenia
Study Objective
To examine social and neuromotor behaviors in children who later developed schizophrenia compared to those who did not.
Childhood Videotaped Social and Neuromotor Precursors of Schizophrenia
Study Design
Longitudinal study using childhood videotapes of Danish children aged 11–13 in 1972, with adult diagnostic follow-up in 1991.
Childhood Videotaped Social and Neuromotor Precursors of Schizophrenia
Key Findings
- Preschizophrenia children showed reduced sociability and, in boys, neuromotor deficits.
- Differences were specific to schizophrenia, not other psychiatric disorders.
Childhood Videotaped Social and Neuromotor Precursors of Schizophrenia
Neuromotor Deficits
Poor motor coordination and increased involuntary movements observed in childhood predicted schizophrenia in adulthood.
Childhood Videotaped Social and Neuromotor Precursors of Schizophrenia
Conclusions
Findings support a neurodevelopmental hypothesis of schizophrenia, with social and motor deficits as early precursors.
Childhood Precursors of Schizophrenia
Neuromotor Abnormalities
Children who later developed schizophrenia displayed higher rates of neurological “soft signs” like involuntary movements, poor coordination, and dyskinesia.
Childhood Precursors of Schizophrenia
Social Behavior Deficits
Children who developed schizophrenia showed reduced sociability, fewer smiles, and less vocal interaction compared to peers.
Childhood Precursors of Schizophrenia
High-Risk Sample
Children with a parent diagnosed with schizophrenia had increased likelihood of developing schizophrenia-related disorders.
Childhood Precursors of Schizophrenia
Gender Differences
Boys showed more pronounced neuromotor deficits, while social impairments were observed across genders.
Childhood Precursors of Schizophrenia
Videotape Coding Variables
Included measures of smiles, laughter, involuntary hand movements, nystagmus-like eye movements, and abnormal motor signs.
Childhood Precursors of Schizophrenia
Strengths of the Study
- Prospective design with standardized videotaping protocols.
- Long-term follow-up (20 years).
- Use of DSM-III-R criteria for adult psychiatric diagnoses.
Childhood Precursors of Schizophrenia
Study Limitations
- Small sample size for schizophrenia group (N=16).
- Moderate interrater reliability for neuromotor measures.
- Missing videotape data for some subjects.
Childhood Precursors of Schizophrenia
Longitudinal Results
Differences in childhood behaviors were consistent with adult diagnostic outcomes, supporting a neurodevelopmental hypothesis of schizophrenia.
Epidemiology of Schizophrenia: Global Insights
Global Prevalence
Schizophrenia affects 1.4–4.6 per 1000 individuals globally, with small variations across populations.
Epidemiology of Schizophrenia: Global Insights
Incidence Rates
Schizophrenia incidence is 0.16–0.42 per 1000 annually, with minimal global variation.
Epidemiology of Schizophrenia: Global Insights
Better Outcomes in Developing Countries
Patients in developing nations have higher remission rates and lower social impairment, often without sustained medication.
Epidemiology of Schizophrenia: Global Insights
Key Risk Factors
Genetic predisposition, early neurodevelopmental issues, and environmental interactions are primary contributors.
Epidemiology of Schizophrenia: Global Insights
Sex Differences
Earlier onset in men; women show better premorbid functioning, outcomes, and fewer brain abnormalities.
Epidemiology of Schizophrenia: Global Insights
Schizophrenia Prevalence
Occurs in 1.4–4.6 per 1000 people globally, with a consistent prevalence across most populations but notable exceptions, such as isolated or endogamous communities.
Epidemiology of Schizophrenia: Global Insights
Incidence Rates
Annual incidence ranges from 0.16 to 0.42 per 1000 individuals, with “broad” criteria (ICD-9) showing higher rates than restrictive diagnostic criteria (DSM or ICD-10).
Epidemiology of Schizophrenia: Global Insights
Better Outcomes in Developing Countries
Schizophrenia patients in developing nations (India, Nigeria, Colombia) experience higher remission rates, better social integration, and less chronic disability compared to those in developed countries.
Epidemiology of Schizophrenia: Global Insights
Potential Factors for Better Outcomes in Developing Countries
Differences may involve acute illness onset, supportive social networks, and reduced stigma, though environmental and genetic interactions are not fully understood.
Epidemiology of Schizophrenia: Global Insights
WHO Ten-Country Study Findings
- Remission rates were higher in developing countries (62.7%) compared to developed countries (36.8%).
- Fewer patients in developing countries required long-term hospitalization or antipsychotic medication.
Epidemiology of Schizophrenia: Global Insights
Sex Differences in Schizophrenia
Men: Earlier onset (by 4–5 years), worse premorbid functioning, and more brain abnormalities.
Women: Better outcomes and higher remission rates, especially post-menopause.
Epidemiology of Schizophrenia: Global Insights
Challenges in Diagnosing Schizophrenia in Epidemiology
- Reliance on self-reports and lack of biological markers complicates diagnosis.
- Verbatim diagnostic interviews (e.g., DIS, CIDI) have limited sensitivity for psychosis.
Epidemiology of Schizophrenia: Global Insights
Impact of Late-Onset Schizophrenia
Schizophrenia onset after 40 years changes sex ratios (more common in women) and symptoms, with predominance of delusions and fewer negative symptoms.
Epidemiology of Schizophrenia: Global Insights
Historical Development of Schizophrenia Epidemiology
- Early studies by Kraepelin focused on heredity and cultural factors.
- Modern epidemiology uses longitudinal and cross-cultural methods to understand schizophrenia’s global distribution.
Epidemiology of Schizophrenia: Global Insights
Population-Specific Observations
- Low prevalence in Hutterite communities due to genetic selection and cultural norms.
- High prevalence in isolated populations like northern Sweden and Croatia due to genetic bottlenecks.
Epidemiology of Schizophrenia: Global Insights
Course and Prognosis of Schizophrenia
- Chronic but highly variable course; up to 60% achieve remission after long-term follow-up.
- Longitudinal studies confirm higher recovery rates in developing nations.
Categorical versus dimensional models of early psychosis
Categorical Model of Psychosis
Psychosis is viewed as a distinct, separate entity from normal mental functioning, classified into discrete disorders like schizophrenia or bipolar disorder.
Categorical versus dimensional models of early psychosis
Dimensional Model of Psychosis
Psychotic symptoms are seen on a continuum, varying in severity across the general population rather than being confined to specific diagnoses.
Categorical versus dimensional models of early psychosis
Key Differences Between Models
- Categorical Model: Clear boundaries between “ill” and “healthy.”
- Dimensional Model: Overlapping symptoms and gradients of severity across populations.
Categorical versus dimensional models of early psychosis
Advantages of the Dimensional Model
- Reflects the full spectrum of psychotic experiences.
- Captures subthreshold symptoms and early markers.
- Allows for personalized treatment approaches.
Categorical versus dimensional models of early psychosis
Limitations of the Dimensional Model
- Challenges traditional diagnostic boundaries.
- Difficult to apply in legal and clinical contexts requiring categorical decisions.
Categorical versus dimensional models of early psychosis
Clinical Utility of Categorical Models
- Clear criteria aid in diagnosis and treatment decisions.
- Useful for research standardization and epidemiological studies.
Categorical versus dimensional models of early psychosis
Continuum of Psychotic Experiences
Psychotic symptoms, such as hallucinations or delusions, occur in milder forms in the general population, with only severe cases meeting clinical thresholds.
Categorical versus dimensional models of early psychosis
Subthreshold Symptoms
Symptoms that do not meet full diagnostic criteria but indicate vulnerability to developing psychotic disorders.
Categorical versus dimensional models of early psychosis
Implications for Early Intervention
Dimensional models support identifying and treating individuals with mild or subclinical symptoms to prevent full-blown psychosis.
Categorical versus dimensional models of early psychosis
Neurobiological Correlates
Evidence supports shared genetic and neurobiological underpinnings across psychotic disorders, aligning with the dimensional model.
Categorical versus dimensional models of early psychosis
Hybrid Approaches
Combines categorical and dimensional perspectives to capture the complexity of psychosis and improve diagnostic accuracy.
Categorical versus dimensional models of early psychosis
Criticisms of Categorical Models
- Oversimplifies complex symptom presentations.
- May overlook individuals with significant impairment but no diagnosis.
Categorical versus dimensional models of early psychosis
Transdiagnostic Research
Studies focusing on shared mechanisms across disorders, supporting the dimensional approach.
Categorical versus dimensional models of early psychosis
Global Burden of Psychosis
Psychotic disorders are significant contributors to disability worldwide, highlighting the need for comprehensive diagnostic models.
Schizophrenia Spectrum Disorders
Schizophrenia Spectrum Disorders
A group of related conditions sharing psychotic features, including schizophrenia, schizoaffective disorder, delusional disorder, and schizotypal personality disorder.
Schizophrenia Spectrum Disorders
Core Symptoms of Schizophrenia
- Delusions: Fixed, false beliefs.
- Hallucinations: Sensory experiences without stimuli, usually auditory.
- Disorganized Thinking: Often evidenced through incoherent speech.
- Abnormal Motor Behavior: Ranges from agitation to catatonia.
- Negative Symptoms: Reduced emotional expression, motivation, or social engagement.
Schizophrenia Spectrum Disorders
Negative Symptoms
- Avolition: Lack of motivation.
- Alogia: Reduced speech.
- Anhedonia: Inability to feel pleasure.
- Asociality: Lack of interest in social relationships.
Schizophrenia Spectrum Disorders
Schizophreniform Disorder
Symptoms similar to schizophrenia but lasting 1-6 months, with no requirement for impaired social or occupational functioning.
Schizophrenia Spectrum Disorders
Schizoaffective Disorder
Features of schizophrenia co-occurring with major mood episodes (depressive or manic) for a significant portion of the illness duration.
Schizophrenia Spectrum Disorders
Delusional Disorder
Persistent delusions lasting 1+ months without other schizophrenia spectrum symptoms.
Schizophrenia Spectrum Disorders
Risk Factors for Schizophrenia Spectrum Disorders
- Genetic Factors: Family history increases risk.
- Prenatal Complications: Malnutrition, infections, or hypoxia.
- Early Developmental Issues: Delays in motor skills or language.
- Environmental Stressors: Urban upbringing, trauma, or cannabis use.
Schizophrenia Spectrum Disorders
Prevalence and Incidence
Schizophrenia affects about 1% of the global population, with onset typically in late adolescence or early adulthood.
Schizophrenia Spectrum Disorders
Neurodevelopmental Hypothesis
Schizophrenia results from disruptions in brain development, influenced by genetic and environmental factors, evident before the illness onset.
Schizophrenia Spectrum Disorders
Differential Diagnosis
Distinguishing schizophrenia spectrum disorders from conditions like mood disorders with psychotic features, substance-induced psychosis, and personality disorders.
Schizophrenia Spectrum Disorders
Treatment Approaches
- Medication: Antipsychotics for symptom control.
- Psychotherapy: Cognitive-behavioral therapy (CBT).
- Rehabilitation: Social skills training and vocational support.
Schizophrenia Spectrum Disorders
Prognosis
Variable outcomes with a spectrum of recovery, from full remission to chronic disability; better prognosis associated with early intervention and supportive environments.
Schizophrenia Spectrum Disorders
Early Intervention Benefits
Treatment during prodromal or early stages improves long-term outcomes, reducing relapse rates and functional impairment.
Schizophrenia Spectrum Disorders
Comorbidities
Common comorbidities include substance use disorders, depression, anxiety, and cardiovascular diseases.
Lessons from the Wings of Drosophila
Timing of Organ Teratogens in Development
The effects of organ teratogens during fetal development depend heavily on timing. For example, the drug thalidomide acts as a teratogen during one specific week of the first trimester, leading to specific and recognizable effects. Similar mechanisms are observed in Drosophila melanogaster, where heat shock during specific developmental windows affects the growth of body parts such as wings and legs.
Lessons from the Wings of Drosophila
Developmental Windows in Drosophila
Each part of the Drosophila body has a unique narrow developmental window. For instance, heat shock during 37-41 hours of the pupal stage can result in wing deformities, while heat shock during 40-44 hours can impair head development.
Lessons from the Wings of Drosophila
Gene Expression and Teratogens
During critical periods of rapid gene expression in Drosophila, teratogens like heat shock can pause development. When the stressor subsides, genes resume expression, but developmental errors remain uncorrected, resulting in deformities.
Lessons from the Wings of Drosophila
Heat Shock as a Model Teratogen
In Drosophila melanogaster, heat shock is used as a model teratogen. It highlights how environmental stress during key developmental windows impacts gene expression and morphology, providing insights into the timing and mechanisms of teratogenesis.
Lessons from the Wings of Drosophila
Insights from Drosophila Models
Studies on Drosophila help understand how early developmental disruptions can lead to disorders like schizophrenia.
Lessons from the Wings of Drosophila
Schizophrenia and Developmental Disruption
Schizophrenia may result from environmental disruptions during critical developmental windows.
Lessons from the Wings of Drosophila
Teratogens and Schizophrenia
Environmental factors, such as infections or toxins, during prenatal development could increase schizophrenia risk.
Lessons from the Wings of Drosophila
Heat Shock Analogy in Schizophrenia
The effects of heat shock in Drosophila are used as a model to study environmental impacts on brain development in schizophrenia.
Lessons from the Wings of Drosophila
Gene Expression and Schizophrenia
Interruption of gene expression during fetal development may lead to errors associated with schizophrenia.
Lessons from the Wings of Drosophila
Critical Periods and Mental Health
Schizophrenia may arise if disruptions occur during critical periods of brain development.
Lessons from the Wings of Drosophila
Environmental Stress and Schizophrenia
Prenatal stressors, such as maternal infection, can influence neural development and increase schizophrenia risk.
Lessons from the Wings of Drosophila
Insights from Drosophila Models
Studies on Drosophila help understand how early developmental disruptions can lead to disorders like schizophrenia.
Lessons from the Wings of Drosophila
Developmental Errors in the Brain
Schizophrenia may be linked to uncorrected developmental errors during prenatal brain growth.
Lessons from the Wings of Drosophila
Teratogenic Mechanisms and Psychiatry
Teratogens illustrate how environmental factors disrupt normal development, offering insights into psychiatric conditions like schizophrenia.
Lessons from the Wings of Drosophila
Timing of Neural Development
The brain’s sensitivity to disruptions during specific developmental phases parallels findings in schizophrenia research.
Epidemiology and Natural History of Schizophrenia
Epidemiology in Schizophrenia
The study of the frequency, determinants, incidence, prevalence, and course of schizophrenia in populations.
Epidemiology and Natural History of Schizophrenia
Lifetime Prevalence Rate of Schizophrenia
Approximately 0.7%.
Epidemiology and Natural History of Schizophrenia
Strongly Confirmed Risk Factors for Schizophrenia
Family history of schizophrenia and lower social class.
Epidemiology and Natural History of Schizophrenia
Insidious Onset
A gradual development of symptoms in schizophrenia, making the exact onset of the illness difficult to identify.
Epidemiology and Natural History of Schizophrenia
Research Designs for Schizophrenia Identification
General population surveys, two-stage community surveys, and treatment setting samples.
Epidemiology and Natural History of Schizophrenia
Risk in Children of Two Schizophrenic Parents
Approximately 46.3% higher risk of schizophrenia compared to the general population.
Epidemiology and Natural History of Schizophrenia
Heritability Estimate for Schizophrenia
60% to 70%.
Epidemiology and Natural History of Schizophrenia
Social Drift Hypothesis
The hypothesis that individuals with schizophrenia fail to achieve their potential due to the illness, explaining the inverse relationship between social class and schizophrenia.
Epidemiology and Natural History of Schizophrenia
Male-to-Female Ratio in First-Episode Schizophrenia
More males than females diagnosed, especially in populations under 35 years old.
Epidemiology and Natural History of Schizophrenia
Season of Birth and Schizophrenia Risk
A slightly higher risk of schizophrenia is associated with being born in winter.
Epidemiology and Natural History of Schizophrenia
Prenatal Complications and Schizophrenia Risk
Complications such as preeclampsia, low maternal weight, small head circumference, and fetal distress increase the risk of schizophrenia.
Epidemiology and Natural History of Schizophrenia
Cannabis Consumption and Schizophrenia Risk
Heavy cannabis use is linked to a higher risk of developing schizophrenia, though causation remains uncertain.
Epidemiology and Natural History of Schizophrenia
Predictor of Relapse in Schizophrenia
Noncompliance with medication after treatment begins is the most consistent predictor of relapse.
Epidemiology and Natural History of Schizophrenia
Suffolk County Mental Health Project 24-Month Findings
40.2% of patients with schizophrenia were continuously ill, and only 13.3% achieved complete remission.
Epidemiology and Natural History of Schizophrenia
Key Factors Affecting Schizophrenia Outcomes
Severity of psychosis and insidious onset significantly influence the course of schizophrenia.
