Limitations of Case Register Studies for Violence and Psychiatric Disorders

To the Editor The Original Investigation by Sariaslan and colleagues¹ is important in questioning previous misperceptions of violence by individuals with serious mental illness and that it is primarily due to comorbid substance misuse.² However, case registers do not have perfect coverage of all mental disorders in a population, and complex cases with co-occurring disorders may be disproportionately registered—those most likely to experience violence and be perpetrators. There is then the problem of temporal proximity.³