A lot of children have parents who abuse alcohol. It has been estimated that 8.3% of all Norwegian children live in homes where at least one of the parents suffer from an alcohol use disorder
]. Research indicates a variety of adverse effects of parental alcohol abuse on the offspring. Particularly, offspring of alcohol abusing parents experience externalizing problems more often than offspring of non-abusing parents
]. The existing literature concerning the impact on internalizing problems – such as mental distress - show less consistent findings, as some studies report detrimental effects of parental alcohol abuse [e.g.
], whereas others do not [e.g.
]. The inconsistency in the literature and the vast amount of children at potential risk warrants more research on the relationship between parental alcohol abuse and offspring internalizing problems.
The gender of the alcohol abusing parent may impact the outcome of the offspring. Previous results suggest that paternal alcohol abuse may represent the strongest risk factor for externalizing problems, whereas maternal alcohol abuse is more strongly associated with internalizing problems
]. In general, maternal alcohol abuse may lead to more serious psychopathology among the offspring than paternal alcohol abuse
]. Findings regarding paternal alcohol abuse and offspring internalizing problems are somewhat conflicting, but the majority of studies do not report significant impact of paternal alcohol abuse after adjusting for other influential variables
]. Several studies do not distinguish between maternal and paternal alcohol abuse, and these studies tend to find an association between parental alcohol abuse and internalizing problems in the offspring
]. The effects of the combined measures of maternal and paternal alcohol abuse may account for some of the inconsistencies in the literature.
Maternal and paternal alcohol abuse may also bestow different risks based on the gender of the offspring, as some studies find that alcohol abuse in the same-sex parent may have a greater impact on the offspring than abuse in the opposite-sex parent
]. Another study found female offspring of alcohol abusing mothers to be prone to depression, whereas male offspring were prone to anxiety
]. Other studies have been unable to find differential effects for male and female offspring
]. Parent–child gender interaction effects have been investigated in a limited number of small studies, and the results need to be interpreted with caution.
Most previous studies have been based on small clinical or community samples. The observed associations may be specific to the sample in which they are investigated and may differ systematically from associations in population based samples. Only a few population studies have investigated the association between parental alcohol abuse and offspring mental health. A Danish registry based study by Christoffersen and Soothill
] investigated the relative risk of hospital admissions for mental illness for offspring of alcohol abusing parents, compared to the remaining population. Parental alcohol abuse did not significantly predict hospital admissions, after adjustments of other adverse life experiences. A population based study by Kessler and colleagues
] found a significant effect of parental substance abuse on offspring mental illness. However, none of these studies segregated the risk of developing externalizing and internalizing disorders, which makes it difficult to know if there is an augmented risk specific to internalizing disorders among offspring of alcohol abusers.
The association between parental alcohol abuse and offspring internalizing problems may be confounded, mediated or moderated by a variety of factors that may complicate attributing poor mental health in offspring specifically to the alcohol abuse of the parent. Many of the studies on adverse effects of parental alcohol abuse have not taken into account the confounding or mediating effect of other potentially influential variables. Comorbid parental mental health problems could be a particularly important mediator, which often has been ignored
]. This may have caused overestimations of the relationship.
Despite the extensive literature, there remain several uncertainties regarding the relationship between parental alcohol abuse and offspring internalizing problems, largely due to lack of control of other influential factors and possibly due to sample characteristics. In the present population based study we want to distinguish the effect of maternal and paternal alcohol abuse and examine whether offspring of alcohol abusing mothers and fathers show more symptoms of mental distress, compared to offspring of non-abusing parents. The confounding, mediating or moderating role of various parental and adolescent factors will be investigated. The design does not permit safe conclusions regarding the status of some of the predictors - as confounders or mediators. Some factors, like age, are confounders by nature, as they are established prior to the onset of alcohol abuse. Other factors may be assumed both to precede and succeed parental alcohol abuse in a causal chain and may thus both confound and mediate the relationship. Nonetheless, we will a priori classify the covariates as confounding or mediating factors, keeping in mind that their statuses as confounder or mediator are only tentative.