Association between Maternal Depression Symptoms across the First Eleven Years of Their Child’s Life and Subsequent Offspring Suicidal Ideation

RESEARCH ARTICLE Association between Maternal Depression Symptoms across the First Eleven Years of Their Child’s Life and Subsequent Offspring Suicidal Ideation Gemma Hammerton1*, Liam Mahedy1, Becky Mars2, Gordon T. Harold3,4, Anita Thapar1, Stanley Zammit1,2, Stephan Collishaw1 1 Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom, 2 Centre for Academic Mental Health, University of Bristol, Bristol, United Kingdom, 3 Andrew and Virginia Rudd Centre for Adoption Research and Practice, School of Psychology, University of Sussex, Sussex, United Kingdom, 4 International Center for Research in Human Development, Tomsk State University, Tomsk, Tomsk Oblast, Russia * OPEN ACCESS Citation: Hammerton G, Mahedy L, Mars B, Harold GT, Thapar A, Zammit S, et al. (2015) Association between Maternal Depression Symptoms across the First Eleven Years of Their Child’s Life and Subsequent Offspring Suicidal Ideation. PLoS ONE 10(7): e0131885. doi:10.1371/journal.pone.0131885 Editor: Klaus Ebmeier, University of Oxford, UNITED KINGDOM Received: April 7, 2015 Accepted: June 8, 2015 Published: July 7, 2015 Copyright: © 2015 Hammerton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Data used for this submission will be made available on request to the ALSPAC executive committee ( alspac-exec@bristol. ac.uk). The ALSPAC data management plan (available here: http://www.bristol.ac.uk/alspac/ researchers/data-access/) describes in detail the policy regarding data sharing, which is through a system of managed open access. Funding: This research was specifically funded by a PhD stipend from the Neuroscience and Mental Health Interdisciplinary Research Group (NNH-IRG) at Cardiff University. SC is supported by the Waterloo Abstract Depression is common, especially in women of child-bearing age; prevalence estimates for this group range from 8% to 12%, and there is robust evidence that maternal depression is associated with mental health problems in offspring. Suicidal behaviour is a growing concern amongst young people and those exposed to maternal depression are likely to be especially at high risk. The aim of this study was to utilise a large, prospective population cohort to examine the relationship between depression symptom trajectories in mothers over the first eleven years of their child’s life and subsequent adolescent suicidal ideation. An additional aim was to test if associations were explained by maternal suicide attempt and offspring depressive disorder. Data were utilised from a population-based birth cohort: the Avon Longitudinal Study of Parents and Children. Maternal depression symptoms were assessed repeatedly from pregnancy to child age 11 years. Offspring suicidal ideation was assessed at age 16 years. Using multiple imputation, data for 10,559 families were analysed. Using latent class growth analysis, five distinct classes of maternal depression symptoms were identified (minimal, mild, increasing, sub-threshold, chronic-severe). The prevalence of past-year suicidal ideation at age 16 years was 15% (95% CI: 14-17%). Compared to offspring of mothers with minimal symptoms, the greatest risk of suicidal ideation was found for offspring of mothers with chronic-severe symptoms [OR 3.04 (95% CI 2.19, 4.21)], with evidence for smaller increases in risk of suicidal ideation in offspring of mothers with sub-threshold, increasing and mild symptoms. These associations were not fully accounted for by maternal suicide attempt or offspring depression diagnosis. Twenty-six percent of non-depressed offspring of mothers with chronic-severe depression symptoms reported suicidal ideation. Risk for suicidal ideation should be considered in young people whose mothers have a history of sustained high levels of depression symptoms, even when the offspring themselves do not have a depression diagnosis. PLOS ONE | DOI:10.1371/journal.pone.0131885 July 7, 2015 1 / 18 Maternal Depression and Offspring Suicidal Ideation Foundation. BM is supported by an Elizabeth Blackwell Institute for Health Research Institutional Wellcome Trust Strategic Award (grant reference: 097822/Z/11/ZR). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. Introduction Suicidal ideation is common in adolescence and is one of the most salient risk factors for later suicide [1]. Therefore, understanding risk factors for suicidal ideation may be important for suicide prevention strategies [2]. Given that a large proportion of young people with suicidal ideation do not present to specialist services, even when their parents are known to services [3], it is crucial to identify those most at risk in community samples. Evidence from existing community studies suggests that maternal depressive disorder is associated with an increased risk of later suicidal ideation in offspring [4,5]. Using a sample of 240 young adolescents and their mothers (the majority of whom had a history of a mood disorder), Garber et al found evidence for an association between maternal history of mood disorder and offspring suicidal symptoms one year later (d’ = 0.13), when adjusting for offspring baseline suicidal symptoms. A more recent study that assessed suicidal ideation repeatedly over a four year period in a sample of college students also found evidence that maternal history of depressive disorder, assessed retrospectively with the student, was associated with persistent suicidal ideation in offspring [5]. The majority of previous literature has examined links between a lifetime diagnosis of maternal depression and offspring suicidal ideation [4,5]. Heterogeneity in the course, timing and severity of depression that might influence risk for offspring suicidal ideation is typically not taken into account [6]. Given that depression can be episodic or persistent, focusing only on a single time point or on presence or not of a lifetime diagnosis could give a misleading impression of the level and duration of maternal depression symptoms that offspring are exposed to. Prospective longitudinal studies enable some aspects of this heterogeneity to be captured by identifying patterns of maternal depression symptoms over time. This allows severity as well as stability or change in maternal depression symptoms over time to be considered. Several studies have demonstrated the added value of using longitudinal trajectories of maternal depression symptoms to predict offspring psychopathology over an assessment at a single point in time or predefined measures of severity and chronicity [6,7], but these have thus far not considered (...truncated)