New data published in Lancet Public Health show that nearly a quarter of children aged between 0 and 16 years are exposed to maternal mental illness. These data come from a national, retrospective cohort study conducted by Professor Kathryn Abel and colleagues in Manchester (UK) and Stockholm (Sweden). Their study included >500,000 children aged 0-16 years and >300,000 mothers who were included in the mother–baby link register of the UK Clinical Practice Research Datalink (CPRD).1
From this large cohort, the researchers found that the overall 2-year prevalence estimate of maternal mental illness (defined as depression, anxiety, non-affective psychosis, affective psychosis, eating disorders, personality disorders, alcohol misuse disorder or substance misuse disorder) in the UK was 23.2%. Importantly, they noted that the prevalence of diagnosed and treated maternal mental illness had risen, as the proportion of exposed children increased by almost 3% between 2005-2007 and 2015-2017. Whether this rise indicates that more mothers are developing a mental illness or that fewer mothers are missed by primary care is unclear. Regardless, Abel et al. show that by the age of 16 years, the cumulative risk of exposure to maternal mental illness is 53.1%.
The researchers also looked at how the prevalence of maternal mental illness varies across the UK. Here, the prevalence ranged from a high of 29.8% in Northern Ireland to a low of 16.8% in London. The identified geographic areas of highest prevalence seem to coincide with the most deprived regions. The researchers suggest, therefore, that more resources could be allocated to areas of higher deprivation, where the prevalence of maternal mental illness is highest.
These latest data add to previous studies conducted in Canada2 and Australia3 that estimated the prevalence of parental mental illness as 12% and 23%, respectively. These prior studies, however, relied on self-reported measures of mental illness rather than primary care data, and thus might be limited by responder bias. By comparison, Abel et al. explain that their UK-based study using the CPRD exemplifies how detailed health records and linkage to survey data can provide reliable information to guide policy and programmes to address the problems faced by children and adolescents and their families.
In an interview for Medical Xpressm,4 study author Matthias Pierce explained that affected children “are more likely to suffer from a range of negative life outcomes, including poorer physical and mental health, lower educational attainment and reduced quality of life”. Consequently, the researchers conclude that long-term planning of high-quality public health initiatives for children affected by maternal mental illness is urgently needed.
Additional studies that report on paternal mental illness are now needed to complete the picture on childhood exposure to parental mental illness.
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Abel, K.M., Hope, H., Swift, E., Parisi, R., Ashcroft, D.M., Kosidou, K., Su Osam, C., Dalman, C. & Pierce, M. (2019), Prevalence of maternal mental illness among children and adolescents in the UK between 2005 and 2017: a national retrospective cohort analysis. Lancet Public Health 4: e291-300. doi: 10.1016/S2468-2667(19)30059-3.
Weis, J.R. & Renshon, D. (2019), Steps towards a comprehensive approach to maternal and child mental health. Lancet Public Health 4: PE268-PE269. doi: 10.1016/S2468-2667(19)30087-8.
2Bassani, D.G., Padoin, C. V., Philipp, D. & Veldhuizen, S. (2009), Estimating the number of children exposed to parental psychiatric disorders through a national health survey. Child Adolesc. Psychiatry Ment. Health 3: 6. doi: 10.1186/1753-2000-3-6.
3Maybery, D.J., Reupert, A.E., Patrick, K., Goodyear, M. & Crase, L. (2009), Prevalence of parental mental illness in Australian families. BJPsych. Bull. 33: 22–26. doi: 10.1192/pb.bp.107.018861.
4Addelman, M. (2019) One in four U.K. children have a mother with mental illness. Medical Xpress: https://medicalxpress.com/news/2019-06-uk-children-mother-mental-illness.html.