The author reviews a series of important Danish studies that have been conducted since 2000 using data from several longitudinal case registers. He acknowledges that the use of such registers has enabled sophisticated analyses of very large numbers of subjects, & highlights the powerful statistical capabilities of these registers by reviewing the studies’ key findings & their implications for clinical practice. He concludes by identifying some of the shortcomings of using National registers in suicide research, & suggests directions for future research. (9 refs)