Journal of Child Psychology and Psychiatry (JCPP) dedicates one whole issue a year to broad-based authoritative reviews by leading authorities on hot topics in the field of child psychology and psychiatry. Widely regarded as a ‘go to’ resource these Annual Research Reviews (ARRs) issues constitute the JCPP's flagship issue for that year. In recent times, under the brilliant editorship of Jim Leckman, we have published themed issues covering broad but clearly delimited domains. For instance in 2011 Jim, together with John March, edited a spectacular number on developmental cognitive neuroscience (Leckman & March, 2011); in 2012 with the impending publication of DSM-5 the topic was diagnostic schemes and nosology (Leckman & Pine, 2012); while in 2013 the focus shifted to resilience (Panter-Brick & Leckman, 2013). That was Jim's last ARR and working from the maxim that ‘nobody does it like him’, we decided that the current ARR 2014 would revert to the more traditional format – making a broad sweep across different fields within child psychology and psychiatry. With this in mind the editors have carefully selected the eight reviews in this ARR 2014 issue to be especially timely and significant and then identified key figures who we believed could prepare for our readers definitive ‘state of the science’ reviews on each topic. In addition, this year, for the first time, each review is accompanied by a commentary penned by a leader in their respective area of research. In each case commentators have really embraced our request for a balanced but appropriately probing piece that really provides the reader with a new perspective and adds value to the review. Without exception the review–commentary combinations are of an exceptional quality and the journal would like to express our thanks to all authors.
I am struck … by the way these diverse articles are united by a recognition of the central importance of developmental perspectives for the science of childhood mental health and disorder … and remind us how much farther we have to go to achieve this vision.
In reading the articles once again in order to prepare this Editorial, I am struck by the way they, though diverse in nature, are united by a recognition of the central importance of developmental perspectives for the science of childhood mental health and disorder. In fact, more generally the need for thoroughgoing developmental approaches appears so widely acknowledged that it is regarded by many as a self-evident truth. The articles in this ARR both articulate the importance of this direction of travel wonderfully well and remind us how much farther we have to go to achieve this vision. Their message is that while the conceptual, theoretical, methodological and logistical challenges remain substantial, the limitations of non-developmental approaches, evident in practically every disorder-related sub-domain of our discipline, leave no viable alternative if we are serious about really understanding the factors that shape mental health and disorder across the lifespan. I have extracted four specific lessons from this year's ARR articles that seem especially important in this regard.
First, models of disorder should be grounded in contemporary knowledge of normal developmental processes and their neurobiological underpinnings. The first two reviews highlight the value of viewing pathology as an aberration of normal development. The question of the role of callous-unemotional traits in the characterisation of conduct disorder has received considerable attention recently (Kahn, Frick, Youngstrom, Findling, & Youngstrom, 2012). Frick and colleagues1 (pp. 532–48) [commentary by Rowe, pp. 549–52] tackle this issue using a development psychopathology framework. They plot trajectories of callous-unemotional traits and demonstrate patterns of continuity and discontinuity and the role of genetic and environmental influences across different periods of development. Building on this they draw on normal studies of pro-social development especially in relation to the emergence of conscience to illuminate which important functions may be lacking in those with these traits and how they might later lead to more significant anti-social conduct disorders. Happé and Frith (pp. 553–77) [commentary by Nelson, pp. 578–81] take on the task of providing a general framework for understanding the neurodevelopmental origins of the range of disorders characterised by altered social cognition (including autism spectrum disorder; Williams syndrome; fragile X syndrome). While also highlighting the need to understand disorder in the light of normal development, these authors extend this approach to include causal models specifying differential effects of deficits in specific neurobiological networks (e.g. mentalizing, emotion and mirror networks) and related cognitive processes (e.g. agent identification, mental state attribution, self-processing and social hierarchy mapping involving social ‘policing’ and in-group/out-group categorization) to explain the emergence of dissociable disorder–specific developmental trajectories.
Second, common causal/developmental mechanisms can play a role in/lead to the emergence of markedly different clinical states. The next two reviews focus on the current hot topic of trans-diagnostic risk processes – in relation to different clinical phenotypes. The role of memory dysfunction has provided an important focus in studies of neuropsychological endophenotypes – deficits in different types of memory function have been implicated in a range of disorders (Rhodes, Park, Seth, & Coghill, 2012). In their article, Goodman and colleagues (pp. 582–610) [commentary by Tannock, pp. 611–4] present an innovative, biologically grounded, model in which common memory deficits in non-executive systems produce aberrant habit-like behaviours across a range of different disorder (e.g., Tourette syndrome, ADHD, OCD). Two memory systems are distinguished – ‘habit’ and ‘cognitive’ – the former grounded in early maturing striatal regions, the latter in the late developing hippocampal regions. The authors speculate that alterations in the maturational rate of these two systems may account for different patterns of symptoms and impairment. In this way they also highlight the potential importance of neurodevelopmental timing and sensitive periods in the pathogenesis of childhood disorders. Karalunas and colleagues (pp. 685–710) [commentary by Kuntsi, pp. 711–3] focus their investigation of shared endophenotypes on the growing corpus of data on reaction-time variability in childhood disorders (Karalunas, Huang-Pollock, & Nigg, 2012). Perhaps against expectation, their meta-analysis found that RT variability is specific to ADHD and is only increased in ASD individuals if they also have ADHD. The authors, fascinated by the possible underlying neurobiological mechanisms, use recently developed mathematical models to demonstrate the potential role of multiple brain systems implicated in state regulation and response organization implicating both bottom up and top down cognitive processes.
Third, the role of environment in neurodevelopmental pathways should not be underestimated. There is still a tendency in some areas to see development as the unfolding of genetically pre-determined programmes of brain growth. In contrast, contemporary developmental models focus on the interaction of environmental and genetic factors in regulating the way that vulnerability and risk and resilience and protective processes work together to determine the onset, persistence, escalation and offset of disorder and impairment. In their ARR article, O'Connor and colleagues (pp. 615–31) [Commentary by Leckman, pp. 632–4] highlight the potentially powerful role of the environment (especially with regard to stress exposure) in shaping brain development and mental health through their review of the exciting literature linking stress exposure, immune function, inflammation and disorder. So far, based largely on animal work (but see Mills, Scott, Wray, Cohen-Woods, & Baune, 2013), the authors help us to make sense of these new insights from a human perspective and to reflect meaningfully on their putative role in shaping developmental pathways to common mental disorders. In their review of harms associated with new online technologies, Livingstone and Smith (pp. 635–54) [commentary by Finkelhor, pp. 655–8] highlight the way in which the nature of risks to which individual children are exposed, varies from generation from generation and how important it is to place developmental models within the changing social-ecological context. The authors highlight the threat posed in particular by aggressive and sexual harms, and the way in which they may place already vulnerable children at increased risk for psychopathology – especially those with pre-existing low self-esteem, low parental support and monitoring and little peer support.
Fourth, longitudinal designs are essential to understand the causes and impact of childhood disorders. Neither of the final two articles in this issue focus primarily on development, but both make important methodological points highlighting the value of developmental perspectives. The first of these two articles by Horga and colleagues (pp. 659–80) [commentary by Castellanos & Yoncheva, pp. 681–4] is a wide-ranging critical review of research studies using magnetic resonance imaging (MRI). Functional magnetic resonance imaging (fMRI), and the spatial resolution it brings to the visualisation of the structure and function of the living human brain, is now very widely employed and has provided important new leads and insights. Its value even as a diagnostic tool is debated (Haubold, Peterson, & Bansal, 2012). Horga and colleagues’ thesis is that the over-emphasis of the power of fMRI technology, as a vehicle, in and of itself, to progress developmental neuroscience, has distracted us from the heavy lifting of normal science – the generation and testing of new hypotheses using appropriate and powerful experimental design. The authors highlight a range of shortcomings of current studies including inconsistency of results and failures to replicate initial findings and limited generalizability to the wider clinical populations. Crucially for us, they highlight a lack of longitudinal studies and a failure to characterise developmental pathways and the related problem of distinguishing biological cause from disorder effects. To address these, the authors highlight the need to integrate MRI technology into strong designs that will allow causal inference to be drawn – including natural experiments and clinical trials. The final article by Beecham (pp. 714–32) [Commentary by Taylor, 733–5] highlights the continuing need to better understand the direct and indirect costs of children disorders and the value of mental health interventions for reducing those costs (Snell et al., 2013). A systematic review of articles published between 2005 and 2012 is provided across common mental disorders of childhood including autism spectrum disorder, attention deficit hyperactivity disorder, conduct disorder and anxiety or depression. Overall the analysis supports the value of current treatments but concludes that, despite the existence of a relatively large number of studies, the variability in the quality of methods makes direct comparison of costs of different treatments and different disorders very difficult. The authors highlight the need for more focus on long-term costs and that lifespan impact of the different disorders is not fully understood, highlighting the need for the adoption of longitudinal perspectives in health economic studies as in other areas of enquiry.
These eight articles (and accompanying commentaries), each in their own way, illustrate the giant strides that have already been taken in bringing about this developmental vision in child psychology and psychiatry. It seems we have been moving ‘Towards …’ developmental accounts, perspectives and models in our field for quite some time. These ARR 2014 articles move us beyond ‘Towards…’.