A three generation study of the mental health relationships between grandparents, parents and children

Children of parents with mental illness are at significantly greater risk for multiple psychosocial problems [1–4]. These children are also more likely to experience developmental delays, lower academic competence and difficulty with social relationships [5–7]. Most inter-generational research has focused on documenting parent–child mental health associations, as parents are typically the most proximal and influential people in a child’s development, particularly during the early years. By virtue of these parent–child mental health relationships, it follows that the mental health histories of grandparents could have some influence on the mental health of their grandchildren. This may occur through a direct relationship with the child, or through their indirect relationship with the child via the parents. Many mental disorders are considered to have a hereditary component to them [8–10], but families also share environments and experiences in addition to their genes.

Studies examining multi-generational mental health relationships have received greater attention in recent years [11–17]. Of the scant literature examining these relationships, there is wide variation in methodologies and in diagnostic tools used to assess mental health problems, including the completeness of family pedigree, the use of direct and indirect assessments and differing interview or questionnaire methods. For example, some of the studies collected mental health data for either maternal or paternal family members [12, 14] where others collected data for both [11, 13]. These variations contribute to a generally mixed and inconsistent range of findings, which we briefly review below.

In the most recent study, Cents et al. [11] found grandparent lifetime anxiety and depression predicted both internalizing and externalizing problems in their 3 year old grandchildren. These associations were independent of parent psychopathology, but were found only when using mother’s, but not father’s, report of children’s internalizing and externalizing problems. Cents et al. also found that for each additional grandparent with a lifetime history of psychiatric disorder, the risk of both internalizing and externalizing problems for children increased by a factor of 1.6–1.7, independent of parental psychiatric disorder.

Using a variety of mental health measures included in the 1970 British Cohort Study, Johnston et al. [17] found a grandparent-parent and parent–child intergenerational mental health correlation of about 0.2. The correlation between grandparent and grandchild mental health was weaker, and the effect persisted across different frequencies of grandparent-grandchild contact. There was no significant grandparent-grandchild correlation once parent mental health was taken into account.

Pettit et al. [14] examined the relationships between grandparent major depressive disorder (MDD), parent psychiatric history, and internalizing problems in children aged 2 to 18 years. They found no evidence of a direct relationship between grandparent MDD and grandchild internalizing problems, however children had higher levels of internalizing problems when both a parent and a grandparent had experienced depression.

Olino et al. [13] examined the extent to which MDD in parents and grandparents, assessed using an array of clinical diagnostic instruments, was related to children’s internalizing and externalizing problems. Parent MDD, grandparent MDD and the interaction of both were associated with children’s internalizing problems at age two. In contrast to Pettit et al. [14], Olino et al. found the presence of MDD in both the parent and grandparent generation did not convey additional risk over and above the direct effect of parent and grandparent MDD on children’s internalizing problems. The presence of grandparent MDD was only associated with internalizing problems in the absence of MDD in both parents.

Weissman et al. [16] used a clinical sample of grandparents to examine the impact of grandparent and parent MDD upon assessments of children’s psychopathology. They found both parent and grandparent MDD was related to children’s psychopathology in middle childhood. They also found children were at greater risk of a mood disorder if they had both a parent and grandparent with MDD. This finding mirrored the results of an earlier study by Warner et al. [15].

Finally, Hammen, Shih and Brennan [12] collected data from a community sample of adolescents, mothers and maternal grandmothers, to examine mental health transmission over three generations, finding that both maternal grandmother and maternal depression had an influence on adolescent mental health. They were unable to assess the influence of paternal depression on children’s mental health outcomes.

These multi-generation studies used different sampling methods and diverse measures of mental health, often collected at a variety of developmental epochs. Several used small samples [15, 16], had limited measures of family socio-demographic environments [12, 13], or lacked mental health data for the full family pedigree [14, 17]. Only one study had complete information on socio-demographic environment and the full family pedigree [11]. Despite these differences, the studies collectively indicate that the mental health histories of grandparents appear to have an effect on children’s mental health, and particularly so in families where mental health problems exist for multiple family members in multiple generations. However, because the pattern of results differs across the studies, it is difficult to ascertain how this occurs. Direct and indirect influences may operate through shared environments, genes, or an interaction of the two.

Grandparents may directly influence the mental wellbeing of their grandchild, which is partially supported by the studies demonstrating a grandparent-grandchild mental health association even in the absence of mental health problems in parents [11, 13, 15, 16]. An example of a direct pathway might be in the way that a grandparent with anxiety disorder interacts with their grandchild. When spending time together, the child may learn through the grandparent’s disposition and behavior that the world should be viewed a frightening place. The child may then learn to become anxious and frightened in general. In such cases, we would expect that the grandparent-grandchild mental health relationship would be stronger in families where children are in frequent contact with their grandparents. Only one of the previous studies examined this idea [17], with results showing that the strength of the grandmother-grandchild mental health association was the same across families with differing frequencies of contact with grandmothers, however the grandmother-grandchild relationship was no longer significant once parent mental health was included in the model.

Such a result suggests that the influence of mental health problems in grandparents could operate indirectly, where the grandparent’s mental health influences parents’ mental health which, in turn, influences the child’s mental health. For example, a grandparent with an anxiety disorder might influence the way their own child views the world. When that child grows up and becomes a parent, at greater risk of anxiety disorder themselves, the parent in turn influences the emotional wellbeing of the grandchild. Thus, the role of grandparents operates via the parent generation. This pathway would be supported by results where the grandparent-grandchild association is no longer observed once parent mental health is accounted for, though this pattern has only been shown in one of the multi-generational studies [17]. Finally, both direct and indirect mechanisms are likely to be in play. Where this occurs we might expect to see an attenuated, though not entirely diminished, relationship between grandparent and grandchild mental health once the mental health of parents has been accounted for. We might also observe an interaction between parent and grandparent mental health on child wellbeing, where the risk of mental health problems in children would increase in terms of both generational proximity and intergenerational burden, which has also been supported by the studies reviewed earlier [11, 14–16].

This study examined multi-generational mental health associations in Australian families in order to further understand the nature of intergenerational mental health associations. We used data from Growing Up in Australia, the Longitudinal Study of Australian Children (LSAC) to investigate how mental health problems in two generations of family members impacted upon children’s subsequent social and emotional wellbeing. Data were collected for over 4,600 children, and included mental health data for mothers, fathers and maternal and paternal grandparents of these children. The LSAC also collects substantial contextual information, including the amount of face-to-face contact children have with their grandparents, along with the family’s social and demographic characteristics. Such data have been relatively rare in other multi-generational studies.

We hypothesized parents would be at greater risk of mental health problems if their own parents (hereafter to be called grandparents) had a history of mental health problems. Second, children would be more likely to have poorer social and emotional wellbeing if they had a grandparent with a history of mental health problems, however this grandparent-child association would be attenuated relative to the more proximal parent–child estimate of association. Finally, we hypothesized that children would have poorer social and emotional wellbeing if they had multiple family members with mental health problems, relative to children with only a parent or grandparent with a mental health problem.

It has only been in the last 10–15 years that research has extended beyond the association between parent and child mental health relationships to consider the link between the mental health of grandparents and grandchildren. The few studies on this topic have generally demonstrated that children of grandparents with a mental illness such as MDD or anxiety disorder are at greater risk of social and emotional wellbeing problems [11–16]. However, there is considerable variability in the results of these studies, and the nature of the grandparent-grandchild mental health association remains unclear. Whilst some studies have found that poor mental health in grandparents predicts poor mental health in grandchildren, independently from parent mental health status [11, 13, 16], others did not find any such relationship [14, 17].

Some of the multi-generational mental health literature has provided support for a cumulative or dose–response pattern, finding children are at greater risk of developing mental health problems if there is a history of mental health difficulties in both the parent and grandparent generations, compared to history in just the parent or grandparent generation [14–16]. However, this pattern has not always emerged [13] or been tested [11, 12, 17] in these multi-generational mental health studies.

There are two key features of this study that merit comment. First, though we found a significant association between a history of mental health problems in maternal grandparents and child SDQ scores, there was no evidence of a cumulative impact on children from having a parent and a grandparent with mental health difficulties, as noted by a the lack of significant interactions between parent and grandparent mental health. However, we did find a cumulative impact of having both a mother and a father with elevated psychological distress for the 8–9 year old children. That is, there appears to be some cumulative impact of having two parents with elevated psychological distress, but no cumulative relationship of children having worse outcomes if they had a grandparent and parent with a mental health problem.

This pattern has not been a consistent result in other multi-generational studies. Of the studies examining the cumulative impact of familial mental health problems, three found evidence of a cumulative relationship [14–16] related to psychopathology and internalizing problems in children. One study did not find a cumulative relationship [13] though this study examined behavior outcomes of children. Cents et al. [11] also found a cumulative impact in the grandparent generation, where the risk of both internalizing and externalizing problems in grandchildren increased for each successive grandparent with an anxiety or depressive disorder.

The second notable finding of this study is that a history of broadly defined nervous and emotional mental health problems in grandparents is associated with elevated SDQ scores, even after controlling for elevated psychological distress in parents. This result suggests that children are susceptible to the mental health influence of grandparents, and supports the notion of some direct impact of grandparental mental health on children. This result is consistent with the other multi-generational studies that have used either community or clinical samples along with comprehensive, validated diagnostic instruments [11–13, 15, 16].

We also found a different pattern of results for the 4–5 year olds compared to the 8–9 year old children. With the exception of paternal grandfathers, there were no significant differences in SDQ scores according to the history of mental health problems in grandparents for the 4–5 year old children. For children aged 8–9 years however, a history of mental health problems in either the maternal grandmother or grandfather was associated with significantly higher SDQ scores. It is difficult to determine why different patterns would be observed for each cohort. It is possible that the older children, by virtue of their age, have had more opportunity to interact with their grandparents, and the association may reflect the accumulation of exposure to potential mental health problems in grandparents, though we are not able to offer additional evidence in support of this. It is also possible that the SDQ measure is more sensitive to problem behavior amongst older children. That average SDQ scores were somewhat higher in the younger cohort of children, particularly amongst those whose parents did not have elevated psychological distress (Table 3) would support this explanation. As such, any relationship between grandparent mental health and child SDQ scores would become more evident when children are older. We do note that some of the other multi-generational studies that used different measures observed a grandparent-grandchild mental health relationship for children as young as two or three years of age [11, 13].

The grandparent-grandchild relationship persisted after controlling for elevated psychological distress in parents, irrespective of the amount of contact with grandparents. This result could suggest that the relationship does not necessarily occur through the face-to-face relationship, but rather through other inherited pathways, be they genetic or environmental and family contexts. For example, mental health problems are more prevalent in disadvantaged families, and previous research has consistently shown there are also strong intergenerational associations in education, occupation, and family income [29, 30]. For many families, the persistence of mental health problems across generations is likely to be tied to these inherited family contexts. However, in assessing the ability of the contact measures to shed light on how these pathways might operate, it is important to note the limitations of the items measuring contact with grandparents. For example, the question did not specify which grandparent the child spent time with. It is possible that grandchildren spend more time with one grandparent than another, particularly in circumstances where grandparents had separated or one had passed away. As such, the measure may not be a reliable indicator of the amount of time spent with the grandparent who had the history of mental health problems and these results should therefore be interpreted with some caution. There are also many reasons that children may have limited contact with their grandparents that could relate to their social and emotional wellbeing. Grandparents may be deceased, or live a long distance away, and for some parents a lack of family support may impact on their wellbeing. There may also be relationship difficulties, perhaps related to mental health, that mean parents feel it is in the best interest of the children that they should have limited contact with their grandparents. As such, it is difficult to hypothesize exactly what role contact with grandparents would have on the grandparent-grandchild mental health association.

There are limitations to this study. The mental health measures used, while commonly employed in large scale epidemiological studies, are not direct measures of psychiatric morbidity. The broad-based developmental focus of the LSAC precluded using diagnostic tools for study children and parents. The questions posed to parents about grandparent’s mental health were very broad and represent secondary and retrospective recall rather than a direct measure on the grandparent. The grandparent mental health questions directed to parents were in the context of their family life when they were growing up. Therefore, for grandparent mental health, the timing, severity and persistence of any nervous or emotional problems is unclear. We cannot determine whether these problems occurred before or after the study child was born and therefore what sort of influence the grandparent may have had on the study child. In this respect, finding grandparent-parent and grandparent-grandchild associations at all demonstrates how strong and pervasive these relationships can be. Also, the relationships documented in this study are observational and as such we cannot make any causal conclusions, particularly in relation to parental mental health. For example, the presence of mental health problems in both parents and children may reflect aspects of their shared environment that have not been accounted for, such as a death in the family or income instability.

For the majority of families, the mother was the informant for her child, her own and the maternal grandparent mental health measures, and the father was the informant for his own and paternal grandparent mental health measures. Therefore, we cannot discount that there may be an informant bias. Such a bias may inflate these intergenerational mental health relationships to be stronger than they might otherwise be, and could be an explanation as to why stronger grandparent-grandchild mental health relationships were found for maternal grandparents than paternal grandparents. However, given some of our findings, it is unlikely that the results we observed were solely due to informant bias. For example, we show that elevated psychological distress in fathers and paternal grandparents was associated with child wellbeing even though mothers completed the SDQ for the majority of children. Additionally, though we used Wave 3 measures for child wellbeing and parent mental health, questions relating to grandparent mental health were collected at Wave 2. Finally, another research study using the LSAC data has shown similar patterns for the intergenerational impacts of joblessness and separation on children [31]. In that study, joblessness and separation in grandparents were associated with lower social and emotional wellbeing, literacy and numeracy achievement in grandchildren. These significant family events are examples of reports that are less biased or subjective than the reports of mental health history used in this study. However, similar patterns were observed, and as such, we have reasonable confidence that results we observed are not solely the result of informant bias.

In acknowledging these limitations, there are several strengths to this study that should also be noted. In addition to the availability of data on both parent and grandparent mental health, our study offers further advances with respect to the strength of the LSAC data. The large sample size and the wide range of socio-demographic characteristics included in this study has alleviated concerns other studies have faced around poor statistical power and allowed us to control for potential socio-demographic confounders, which previous studies could not achieve. Though contact with grandparents did not modify the grandparent-grandchild association, assessing the amount of face-to-face contact children had with their grandparents is particularly important as the ability of grandparents to directly influence the mental wellbeing of their grandchildren would be constrained in situations where grandparents see their grandchildren less frequently. These relationships require further research with more informative measures as to the nature of the relationship that grandparents have with their grandchildren.

With the noted limitations in mind, we can conclude from this study that assessments of children’s social and emotional wellbeing should take into account a full family history of mental health problems. Grandparent mental health relates to parental mental wellbeing, which in turn is associated with the wellbeing of children. However, there is also a direct mental health relationship between grandparents and grandchildren independent of mental health difficulties in parents.