In the part about limitations, the linked paper says

> Although several important confounders were adjusted for, the observed independent associations may nonetheless have been prone to residual confounding. This is because many salient adverse childhood experiences, including most instances of abuse and neglect, are not routinely registered. The underlying reasons for residential change, such as family dissolution, were also unknown. Furthermore, socio-economic trajectories among the cohort members beyond their 15th birthdays, which could have mediated the observed associations, were not examined. Selection of potential confounders was essentially restricted according to their availability, which is a common limitation of many studies conducted using administrative registers. An unknown degree of reverse causality bias may also have been present. Earlier unregistered problematic behaviors among older children and adolescents may have motivated some families to relocate to start afresh. However, it seems unlikely that these hidden biases could wholly explain the strong links observed between residential mobility in early/mid-adolescence and subsequent adverse outcomes. Finally, the findings may not apply universally beyond Denmark, although it seems likely that they are relevant to other western societies with similar drivers of residential mobility.

I quickly skimmed some of your comment history. You are clearly capable of writing much more constructive comments than this. I encourage you to do so :)

It isn't a great look to snidely put down people who have experienced difficulty and are simply trying to understand themselves better.