Epidemiological Challenges in the Study of Behavioral Addictions: a Call for High Standard Methodologies

Purpose of Review
The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) categorizes gambling disorder in the section on substance-related and addictive disorders, and the 11th revision of the International Classification of Diseases (ICD-11) includes both gambling and gaming disorder as disorders due to addictive behaviors. However, there is less evidence for other putative behavioral addictions. This review focuses on requirements for epidemiological studies of disorders that may be considered as behavioral addictions and compares the current state of research with principles of sound epidemiological research.

Recent Findings
In studies of behavioral addictions, samples are often quite small, which may lead to increased random error. The lack of sound assessment tools—particularly the lack of agreed-upon diagnostic criteria and standardized diagnostic interviews—may also increase systematic error. Other concerns related to systematic bias include the use of convenience samples, lack of pro-active recruitment, inadequate assessment of confounding variables, and a dearth of representative and longitudinal studies.

Summary
This review recommends that future studies of putative behavioral addictions should more closely adhere to methodological standards of epidemiological research to reduce random and systematic error. Specific recommendations are detailed to advance epidemiological research in this area with the aim of improving the evidence base and generating more refined public health recommendations and policies.