Week 3: Epidemiology of Mental Disorder Flashcards
The study of how diseases (or, more broadly, health problems) spread and affect a population.
Epidemiology
The study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.
Epidemiology
What does Epidemiology involve?1
1) Defining ‘disorders’
2) Counting and mapping ‘disorders in place and time
3) Linking the occurrence of ‘disorder’ to potential causative factors
4) Identifying appropriate (public health) interventions
Two strands of Epidemiology
1) Descriptive Epidemiology
2) Analytical Epidemiology
This branch of epidemiology focuses on describing the characteristics of a disease or health condition within a population.
It aims to explain:
- prevalence
- incidence
- variations between populations
- comorbidities
- burden of disorder
Descriptive Epidemiology
This branch of epidemiology aims to identify the causes and risk factors of a disease or health condition.
It involves studying different groups of people (e.g., those with and without the disorder) to determine the factors associated with its development.
Analytical Epidemiology
Considered one of the founders of modern epidemiology.
His investigation of the 1854 cholera outbreak in London is a classic example of how epidemiological principles can be used to identify the cause of a disease and implement effective control measures.
John Snow
A specialized field that applies epidemiological principles to the study of mental disorders.
Psychiatric Epidemiology
Goals of Psychiatric Epidemiology
1) Understand mental disorders (onset, course, and outcomes)
2) Measure the burden on society
3) Identify risk factors
4) Develop prevention strategies
The underlying biological, psychological, and social processes involved in the development of mental disorders.
Causal Mechanisms
The prevalence, incidence, and variation of mental disorders within a population.D
Distribution
Key Concepts in Psychiatric Epidemiology
1) Caseness
2) Incidence
3) Prevalence
Caseness
Incidence
The presence of a mental disorder as determined by specific diagnostic criteria (e.g., those outlined in the DSM-5).
Prevalence
The number of new cases of a mental disorder that occur within a specified period of time, typically a year.
Incidence
The proportion of individuals in a population owho have a mental disorder (total number of cases) at a specific point in time (point prevalence) or over a defined period (e.g., one-year prevalence, lifetime prevalence).
Prevalence
Steps in conducting Descriptive Epidemiology
1) Identify/define the population of interest
2) Select the sample of the population to study
3) Conduct structured interviews to collect data
4) Analyze data
5) Interpret findings
6) Disseminate results
What does Analytical Epidemiology involve?
Population-based studies
Structured analysis
Correlation and causation: Ex. Case-control studies
Various methodologies: Ex. Cohort studies, twin studies, family studies
Compare individuals with a mental disorder (cases) to individuals without the disorder (controls).
Case-control Studies
Goal: Estimate the prevalence of mental disorders in various communities across the United States
Methods: Structured interviews based on DSM-III
Findings: Prevalence and distribution of mental disorders in different populations
Epidemiological Catchment Area (ECA) Studies (1980s)
Goal: Examine the prevalence, comorbidity, and correlates of mental disorders in the United States
Methods: Large-scale survey with structured interviews based on DSM-III-R criteria
Findings: High prevalence of mental disorders, particularly comorbid conditions, and their impact on individuals and society
National Comorbidity Study (NCS) (1990s)
Goal: Replicate the findings of the NCS and examine changes in the prevalence of mental disorders over time
Methods: Large-scale survey with structured interviews based on DSM-IV criteria
Findings: Confirmed the high prevalence of mental disorders and identified trends in their occurrence over time.
National Comorbidity Study Replication (NCSR) (2000s
Is a statistical measure that compares the probability of an event occurring in an exposed group to the probability of it occurring in a non-exposed group.
Example: Doll and Hill’s study on smoking and lung cancer calculated the relative risk of lung cancer for smokers compared to non-smokers.
Relative Risk or Risk Ratio
Key Findings from the National Comorbidity Study Replication (NCSR)
1) Mental illnesses are common
2) Early onset (24 y/o)
3) Serious or moderate severity
4) Comorbidity is common
5) Access to treatment is limited, delayed, or subpar
Refers to the process of dividing a population into subgroups based on specific characteristics or variables. These subgroups are often called strata.
Example: In Doll and Hill’s study, the researchers stratified the population of smokers by smoking habits (e.g., light smokers, heavy smokers). This allowed them to examine how the risk of lung cancer varied across different levels of smoking exposure.
Stratification
Is a statistical measure that compares the odds of an event occurring in one group to the odds of the event occurring in another group.
It is often used in epidemiological studies to assess the association between an exposure (e.g., smoking) and an outcome (e.g., lung cancer).
Odds Ratio
Early epidemiological studies primarily focused on these factors such as migration, urban living, psychosocial stressors, and life events as potential risk factors for mental disorders.
Social Factors
Examining the role of inflammation in common mental disorders.
Inflammatory Biomarkers
This emerging field combines traditional epidemiological methods with biological and genetic approaches to investigate the underlying causes of mental disorders.
New Psychiatric Epidemiology
refers to the underlying processes or factors that contribute to the development of a disease or condition.
In the context of mental disorders, it can involve biological, psychological, social, or environmental factors
Causal Mechanisms
