What parent doesn't wonder how their "issues" may affect their children's well-being? It's a source of , uncertainty and concern. Understanding risk factors for mental illness is important, because some of them may be modifiable, allowing for prevention of future problems if they are identified early enough. There is a sizeable body of research on the subject of how maternal issues associate with mental health problems in offspring. Notably, Stein et al. (2014) identified higher risk with younger mothers, less educated mothers, and mothers with mental illness.

The authors of a new study, Pearson et al. (2017), note that among risk factors, parental traits have not been well-studied. Personality is an important factor in child-rearing and would be expected to have a potentially strong impact on . Reviewing the prior literature, the authors report that prior cross-sectional studies find that maternal is correlated with poor maternal competence and satisfaction, and furthermore, with behavioral problems among children.

Other studies they review look at the roles of personality traits connected with more emotionally distant : suspiciousness, anger, and impulsivity. These traits are characteristic of some , notably (BPD), which is marked by unstable relationships, , suspiciousness, novelty-seeking, self-destructive behaviors, and disturbance.

They note that children of mothers with BPD show difficulties with , social withdrawal, and emotion dysregulation earlier in life, and later in development tend to have continuing difficulty with social behaviors and distortions in how they perceive interpersonal relationships. These characteristics may be related to a tendency for mothers with BPD to be less sensitive, more intrusive, more hostile, and more over-protective. They report on two small cross-sectional studies which suggest an association with maternal BPD and adolescent and .

It is worth noting as a relevant aside that, although the study authors do not address this issue in detail, BPD is viewed by many to be related to developmental —and some believe it is at least partially a form of complex posttraumatic disorder (cPTSD), though this question is still being debated, and there appear to be genetic factors that contribute to the development of BPD. In analyzing different BPD symptoms to determine how much is heritable and how much environmental, Reichborn-Kjennerud et al. (2013) found that BPD broke down statistically into three domains: a general BPD susceptibility factor, 55% heritable and 45% environmental; an interpersonal factor (unstable relationships, fears of abandonment), 2.2% heritable and 97.8% environmental; and an emotional instability factor (feelings of emptiness, intense anger), 29.3% heritable and 70.7% environmental.

So, there are significant heritability factors. But much of how mothers with BPD treat their children is related to their own developmental experiences, suggesting strongly a component of transgeneration transmission of trauma—passing negative developmental experiences to offspring via —and perhaps also via factors, which researchers are finding are increasingly important in how trauma is passed from one generation to the next.

There is consensus that maternal personality is likely an important factor, but there are few if any prospective studies investigating the question about parental personality and the impact on the mental health of their children. Generally speaking, prospective longitudinal studies offer better statistical results than cross-sectional studies, because they look at people over long spans of time, checking hypotheses in a naturalistic setting rather than looking at one data set during a shorter time span. This allows researchers to draw more reliable and robust conclusions about causality rather than simply being able to identify associations.

The study authors set out to investigate the role of parental personality using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) data set. They tested the following hypotheses:

(1) At the level of the general population, dysfunctional maternal personality traits at child age 9 years will be associated with an increased risk of offspring mental health problems at age 18 years.



(2) Greater risk will be associated with the presence of greater numbers of dysfunctional maternal personality traits. (3) Any associations will be independent of maternal depression.

Out of the sample of more than 14,000 mothers and their families, they had complete data on more than 8,000 mothers and children and nearly 2,000 fathers and children. They looked at parental personality measured when the children were 9 years old and characteristics of the children 9 years later, at age 18.

For the parents, they measured dysfunctional personality traits using the Karolinska Scales of Personality inventory, which looks at 15 personality traits related to somatic anxiety, psychic anxiety, muscular tension, psychasthenia, inhibition of , irritability, , socialization, social desirability, monotony, avoidance, impulsivity, verbal aggression, indirect aggression, suspicion and detachment—many of which overlap with neuroticism and depressive traits. They looked at five traits distinct from neurotic and depressive traits—novelty seeking (monotony avoidance), impulsivity, verbal anger, suspicion, and detachment—which are more connected with relationship difficulty and emotional dysregulation, in order to distinguish neuroticism, depression and other personality factors from one another.

The 18-year-olds completed the Clinical Interview Schedule - Revised. This is a broad tool which covers multiple symptom domains and uses a computer program to determine what disorders are present, if any. Of particular interest were , anxiety disorders, and self-harming behaviors.

Their findings are interesting. While in general, dysfunctional maternal personality traits were associated with increased risk for children's mental illness, most traits were interrelated and not independently significant. Maternal suspicion had an independent effect, increasing the odds of all outcomes, and maternal impulsivity increased the likelihood of depression specifically. Additional analysis reinforced the finding that altogether, maternal personality dysfunction is correlated with mental health problems in children, increasing the likelihood of depression, anxiety disorders, and , independent of maternal neuroticism. The greater the extent of maternal personality dysfunction, the greater the risk of negative outcomes for the children.

Further research is needed to understand how maternal personality traits lead to adverse outcomes for children, and in particular the relationship between maternal impulsivity with depression in children independent of maternal depression. Because this effect of impulsivity is independent of depression (itself an independent non-personality related risk factor), it suggests that maternal impulsivity, independent of genetic risk factors for depression, has a negative effect on children. In general, though personality can be difficult to modify and many dysfunctional traits are stable over time, the research suggests that it may be possible to prevent or mitigate negative outcomes in offspring by modifying maternal behavior.

Coming back to the subject of the impact of trauma on personality, and intergenerational transmission of trauma, the example of Ububule springs to mind. Ububule is an organization started in 2000 in South Africa, based on attachment theory, to provide hands-on parenting training for predominantly mother-child pairs to prevent the transmission of trauma from one generation to the next. Using trained staff to foster more adaptive maternal behaviors, Ububele works to enable families to raise children to have a more secure attachment style, leading to improved outcomes. Similarly, Columbia-Presbyterian's Parent-Infant Psychotherapy Program does hands-on work with families to effect positive changes by intervening early on to teach mothers (typically) to more accurately interpret infant behaviors (for example, responding with recognition and rather than suspicion and hostility) and respond in ways that foster better developmental outcomes.

And what about fathers? Interestingly, and somewhat surprisingly, Pearson et al. found that paternal dysfunctional personality traits had no significant impact on the mental health of their children at age 18. On one hand, this seems like good news because it may put fathers more at ease, at least in terms of the impact of personality on how their kids turn out. (So, happy Father's Day...?)

On the other hand, it raises many questions about what impact the father does have on child development—and whether fathers might be able to mitigate the effect of negative maternal personality on their children given greater awareness of the impact of negative maternal personality traits. It may also be that the father's personality comes into play with mate selection.

Further research is required to understand the more complicated interactions among father, mother, and child that were not addressed in the current study. It may simply be that whoever spends more time with children has the greatest impact. Whoever the primary is, regardless of whether they're the father the mother or somebody else, has a greater impact on development. As family structures change and evolve, no doubt future research will reveal more nuanced and generalizable findings.

For any parents reading this, and related folks feeling concerned—rather than blame or worry, consider working toward positive changes, because it is possible to improve many of these issues, and seek professional consultation if appropriate.

Please send questions, topics or themes you'd like me to try and address in future blogs, via my PT bio page.