Epidemiology is the study of disease transmission and prevalence in a population. Although it is often used to track movement of infectious disease, epidemiology can also be used to map the characteristics of non-communicable diseases such as psychiatric illness. Psychiatric epidemiology researchers look at factors such as where diseases often occur, the number of those affected, and which public health interventions are useful in reducing the level of illness. Interpretation of statistics, collation of medical records, and research studies are all important tools for a person investigating aspects of psychiatric epidemiology.
Psychiatric illness is generally not related to infectious diseases, so it does not have the ability to move from person to person. In a certain population, such as a city, for example, the presence of this type of disease does not follow as predictable a pattern as infectious disease. Despite this, psychiatric epidemiology can still be a useful tool for researchers, who want to get the big picture of disease in a population.
To do this, scientists need data to make up a realistic picture of a population. This data can be gleaned from existing sources like medical records and statistics already calculated by other researchers. Often, though, a researcher has to create new data sources such as getting people to fill in questionnaires or undergo interviews. Once he or she gets all the data necessary, statistics and computer programs that create models of the information, are typically used to produce usable and understandable results from the raw data.
Suicide, for example, falls into the realm of psychiatric illness. Various factors can make the risk of suicide more likely in certain people than in others. A person with an pre-existing psychiatric disease, such as schizophrenia, may be more at risk of suicide, whereas a person with a different psychiatric problem may not be at increased risk. If a psychiatrist knows the likelihood of a person committing suicide based on his or her existing disease, then the psychiatrist may be able to tailor the person's treatment accordingly. Other indicators that may affect the chance of suicide, for example, could be issues like abuse, lack of social life, or poor socioeconomic conditions.
Data from psychiatric epidemiology can also be used to tailor public health services to those people who need it most. When a researcher finds that depression, for example, is particularly high in women who have just given birth, then nurses and doctors can be particularly vigilant for signs of post-natal depression in new mothers, and put treatment systems in place accordingly. Emergence of previously rare psychiatric problems such as attention-deficit and hyperactivity disorder (ADHD) can also be mapped and identified using psychiatric epidemiology, bringing the attention of the health authorities to the problem.
