Psychiatric epidemiology
Encyclopedia
Psychiatric epidemiology is a field which seeks to study the conceptualization, etiology
, and prevalence
of mental illness
in society. It is a subfield of the more general epidemiology
. It is very difficult to accurately study mental illness conceptualization, etiology, and prevalence, and current techniques are relatively poor. Two areas of concern, sometimes called the crisis of psychiatric epidemiology today, are the high estimates of mental illness
that many studies produce and the difference in results between studies.
. Sensitivity is a measure of how well a given selection criteria detects all of the people with a specific mental illness. Specificity is a measure of how well the technique identifies people with a mental illness without falsely identifying people without a mental illness.
is a measure of how well the study measures what it is intended to measure. Reliability
refers to how consistently the same result can be achieved. If an experiment is not reliable or valid, it will not withstand peer review
.
and Darrel A. Regier conducted a study called the Epidemiological Catchment Area Project which surveyed samples of the general population at five sites across America. In the study, it was found that about a third of all Americans suffer from mental illness at some point in their lives. This statistic is often referred to as lifetime prevalence.
of symptoms and character traits can have a damaging effect on those that display these symptoms and traits. For example, a person being surveyed for major depressive disorder in the ECA project would be asked questions such as "In your lifetime, have you ever had two weeks or more during which you felt sad, blue, depressed
, or when you lost all interest and pleasure in things that you usually cared about?" Although many people would answer yes to this question, it is not necessarily because they were experiencing depression. Rather, they could be experiencing a natural reaction to some kind of life stress. By labeling this reaction as a mental illness, it increases the stigma
of the person's symptoms and thus creates problems for their recovery.
Studies like the ECA
do not draw the line between mental illness and normal human stress responses. This creates many problems for those who suffer from both mental illness and those who don't by decreasing the seeming seriousness of mental conditions and increasing the stigma on those who are suffering a stress response.
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
, and prevalence
Prevalence
In epidemiology, the prevalence of a health-related state in a statistical population is defined as the total number of cases of the risk factor in the population at a given time, or the total number of cases in the population, divided by the number of individuals in the population...
of mental illness
Mental illness
A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...
in society. It is a subfield of the more general epidemiology
Epidemiology
Epidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
. It is very difficult to accurately study mental illness conceptualization, etiology, and prevalence, and current techniques are relatively poor. Two areas of concern, sometimes called the crisis of psychiatric epidemiology today, are the high estimates of mental illness
Mental illness
A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...
that many studies produce and the difference in results between studies.
How studies are conducted
The common technique for psychiatric epidemiological research today is structured interviewing, a technique in which a series of questions is administered by lay interviewers to determine whether an individual is disordered or nondisordered.Clinical versus actual prevalence
Clinical prevalence is a measure of how many people who seek out mental health services are actually diagnosed with a mental illness, whereas actual prevalence is the number of people in all of society who have a mental illness. It is much easier to study clinical prevalence because people with mental illness are identified by receiving a diagnosis, but epidemiologists are most interested in actual prevalence. To that end, efforts are continually made to improve research techniques in order to better estimate the actual prevalence of mental illness.Sensitivity and specificity
Another concern of psychiatric epidemiological studies are the issues of sensitivity and specificitySensitivity and specificity
Sensitivity and specificity are statistical measures of the performance of a binary classification test, also known in statistics as classification function. Sensitivity measures the proportion of actual positives which are correctly identified as such Sensitivity and specificity are statistical...
. Sensitivity is a measure of how well a given selection criteria detects all of the people with a specific mental illness. Specificity is a measure of how well the technique identifies people with a mental illness without falsely identifying people without a mental illness.
Validity and reliability
In order for a study to be useful, it must be both valid and reliable. ValidityValidity (statistics)
In science and statistics, validity has no single agreed definition but generally refers to the extent to which a concept, conclusion or measurement is well-founded and corresponds accurately to the real world. The word "valid" is derived from the Latin validus, meaning strong...
is a measure of how well the study measures what it is intended to measure. Reliability
Reliability (statistics)
In statistics, reliability is the consistency of a set of measurements or of a measuring instrument, often used to describe a test. Reliability is inversely related to random error.-Types:There are several general classes of reliability estimates:...
refers to how consistently the same result can be achieved. If an experiment is not reliable or valid, it will not withstand peer review
Peer review
Peer review is a process of self-regulation by a profession or a process of evaluation involving qualified individuals within the relevant field. Peer review methods are employed to maintain standards, improve performance and provide credibility...
.
Example: The Epidemiological Catchment Area Project
In an attempt to measure the prevalence of mental illness in the United States, Lee RobinsLee Robins
Lee Nelken Robins was an American professor of social science in psychiatry and a leader in psychiatric epidemiology research. She was affiliated with the Washington University in St. Louis for more than 50 years from 1954 until 2007.-Early years:Robins was born in New Orleans, Louisiana...
and Darrel A. Regier conducted a study called the Epidemiological Catchment Area Project which surveyed samples of the general population at five sites across America. In the study, it was found that about a third of all Americans suffer from mental illness at some point in their lives. This statistic is often referred to as lifetime prevalence.
Sociological concerns
There is a negative consequence to the conduction of studies that are not valid and reliable. The medicalizationMedicalization
Medicalization is the process by which human conditions and problems come to be defined and treated as medical conditions and problems, and thus come under the authority of doctors and other health professionals to study, diagnose, prevent or treat...
of symptoms and character traits can have a damaging effect on those that display these symptoms and traits. For example, a person being surveyed for major depressive disorder in the ECA project would be asked questions such as "In your lifetime, have you ever had two weeks or more during which you felt sad, blue, depressed
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
, or when you lost all interest and pleasure in things that you usually cared about?" Although many people would answer yes to this question, it is not necessarily because they were experiencing depression. Rather, they could be experiencing a natural reaction to some kind of life stress. By labeling this reaction as a mental illness, it increases the stigma
Social stigma
Social stigma is the severe disapproval of or discontent with a person on the grounds of characteristics that distinguish them from other members of a society.Almost all stigma is based on a person differing from social or cultural norms...
of the person's symptoms and thus creates problems for their recovery.
Studies like the ECA
ECA
ECA may refer to:Government and government agencies:* Bureau of Educational and Cultural Affairs, a part of the United States Department of State* Economic Cooperation Administration, a former United States government agency...
do not draw the line between mental illness and normal human stress responses. This creates many problems for those who suffer from both mental illness and those who don't by decreasing the seeming seriousness of mental conditions and increasing the stigma on those who are suffering a stress response.