thus had lower power, making it more difficult to detect true small effects. However, null findings for nicotine persistence do not appear to be due to low power, given the larger sample size and low adjusted odds ratio magnitude. Fourth, incremental analyses assume that the varied maltreatment types affected persistence risk equally, implying equal “harm magnitude”. Future research could investigate this assumption. Finally, this study does not explore more complex issues such as (a) the possibility that these associations may differ for different demographic groups, or (b) the possible existence of mediators that could explain these associations. Exploration of interactions with demographic variables could provide insight on groups most at risk; such analyses are beyond the scope of the current paper and should be assessed through deliberate a-priori testing after hypothesis development in future research. Similarly, future research is also needed to determine why history of childhood maltreatment impedes recovery from alcohol and nicotine dependence.
