These results should be interpreted in the context of three potential methodological limitations. First, while ascertaining cases of DA, CB and AUD from registry data has important advantage, especially independence from subject cooperation and accurate recall and reporting, it also has significant limitations. In Sweden as in most other countries, a majority of most crimes are not officially reported or do not result in a conviction so we are sampling from the more severe end of the spectrum of criminal activities (Swedish National Council for Crime Prevention 2008). For DA and AUD, there are surely false negatives for individuals who abuse substances but avoid medical or police attention. The validity of our detection of these syndromes is supported by evidence for strong co-registration across our registries. The mean OR for case detection of DA across our 5 relevant registries was 52 (Kendler et al. 2012) and for AUD across 4 registries was 33 (Kendler et al. 2014).
