First paper combining four CID cohorts examines parental age and behavioural problems

Data from 32,892 children was used to examine the relation between parental age and behavioural problems in a recent paper published in Child Development. The children were part of four Dutch longitudinal cohort studies: Generation R, the Netherlands Twin Register, the Research on Adolescent Development and Relationships-Young Cohort (RADAR-Y), and the Tracking Adolescents’ Individual Lives Survey (TRAILS). They represent the entire Dutch geographic region across all strata of society and a range of socioeconomic statuses. To combine the results across all four cohorts and find robust results, the researchers used a cutting edge Bayesian research synthesis technique.

The plan for a multi-cohort study examining parental age and behavioural problems arose at a consortium on individual development (CID) principal investigator (PI) meeting. Ever since, despite being spread across the country, the project has had the full support of the PIs, cohorts, analysts and data-managers involved.

Multidisciplinary collaboration

The resulting paper is a fine example of CID’s added value by incorporating not just all four work package 3 cohorts, but using statistical know-how from work package 4. A reflection of this multidisciplinary collaboration is the joint first authorship of Mariëlle Zondervan-Zwijnenburg (WP4 PhD student) and Sabine Veldkamp (WP3 PhD student). Another indication is the diverse expertise of important members of the manuscript writing team, PI’s Tineke Oldehinkel (professor of lifecourse epidemiology of common mental disorders at University Medical Center Groningen), Dorret Boomsma (professor of biological psychology and behavior genetics at Vrije Universiteit Amsterdam) and Herbert Hoijtink (professor of applied bayesian statistics at Utrecht University). To combine and interpret the results, they needed the input from the cohorts as well as methodological assistance.

No evidence for harmful effect of advanced parenthood on behavioural problems

Amid a trend towards delayed childbearing, the researchers examined the contribution of maternal and paternal age on externalizing and internalizing behavioural problems in children around age 10-12 years. Unexpectedly, there was no indication of more behavioural problems in children of older parents. In fact, there was evidence that older parents have children with fewer externalizing behaviour problems. This favourable effect of parental age was still present when adjusting for socioeconomic status (SES), indicating it is not solely due to SES. For internalizing problem behaviour no relationship, either positive or negative, was found with parental age. Overall, this study suggests there is no reason for (future) parents to worry about a harmful effect of advanced parenthood on behavioural problems during early adolescence (10-12 years).

More information:

Here Mariëlle Zondervan-Zwijnenburg explains how the Bayesian research synthesis technique was applied for this study.

Press release Child Development

Dutch press release by Utrecht University and VU Amsterdam.

Zondervan-Zwijnenburg M.A.J.*, Veldkamp S.A.M.*, Nelemans S.A., Neumann A., Barzeva S.A., Branje S.J.T., Van Beijsterveldt C.E.M. Meeus W.H.J., Tiemeijer H.W., Vollebergh W.A.M., Hoijtink H.J.A., Oldehinkel A.J., Boomsma D.I. (2019) Parental age and offspring childhood mental health: A multi-cohort, population-based investigation. Child Development. http://doi.org/10.1111/cdev.13267

*These authors contributed equally