Investigating Children at High Risk for Bipolar and Psychotic Disorders: Findings and Implications

Abstract

Bipolar disorders (BDs) and psychotic disorders were initially conceived as disorders of adulthood, with an occasional onset in adolescence. However, those concepts are gradually changing, and, based on recent studies of children of parents with BD and psychotic disorders, these aged constructs require intense rethinking. A series of longitudinal studies paints a new, different picture: the true beginnings of these disorders were either different or have changed. In nearly all departments of psychiatry, adult and childadolescent psychiatry represent 2 separate universes that did not enable continuous studies. However, in recent years, several adult and child specialists have joined forces to investigate the populations of young people at high risk for BDs and psychotic disorders and came up with identical basic findings regarding the early clinical course. This issue of The Canadian Journal of Psychiatiy offers 2 excellent reviews of this fruitful approach by its major proponents, Dr Anne Duffy1 and Dr Patrick D McGorry, Dr Barnaby Nelson, Dr Sherilyn Goldstone, and Dr Alison R Yung.2 They present their findings, and review the relevant literature and convergent conclusions. They report replicated evidence that, in predisposed people over time, major mood and psychotic disorders develop from nonspecific harbingers. Based on her longitudinal studies of offspring of affected parents, Dr Duffy' describes the early natural history of BD as unfolding in a series of clinical stages. BDs evolve from nonspecific childhood antecedents, including anxiety and sleep problems, followed by adjustment and minor mood disturbances through early adolescence, culminating in major mood episodes in later adolescence and early adulthood. As BDs have a forceful genetic contribution, the study of children of affected parents is an important strategy to capture this unfolding of the illness. The clinical staging model is likely to improve early detection and may enable early intervention. Interestingly, Dr Duffy 's longitudinal studies shed light on seemingly contradictory findings that emerged from earlier cross-sectional high-risk studies and studies of pediatrie clinical populations. To wit, the diversity of BDs in parents appears to explain why ADHD and other cognitive difficulties are reported in some high-risk offspring studies and not in others. Studies focusing on the early phase have also mushroomed in psychotic disorders. Dr McGorry and coauthors2 introduce an ultra-high-risk (UHR) approach to identify people in the prodromal phase of psychotic disorder. UHR criteria are based on a combination of known trait and state risk factors for psychosis, including attenuated positive psychotic symptoms, brief self-limited psychotic symptoms, and a family history of psychotic disorder. Early identification is critical, as meta-analysis, as well as systematic reviews, demonstrated that a longer duration of untreated psychosis is associated with worse outcome, poorer response to antipsychotic treatment, and greater neuroimaging changes. Moreover, intervening during the early stages appears to reduce the burden of disability and the prevalence of full-blown illness. An imperative reason for offering these 2 papers1,2 here together is their striking convergence. In particular, in their longitudinal investigations, the authors have found evidence of staging during the development of the disorders. Staging, a notion already recognized in other areas of medicine, is a more advanced way of characterizing a disorder. These findings are both comforting and disturbing. Comforting, because we are finally learning about the early stages of major disorders from prospective observations. Disturbing, because they point to the limitations of the symptom-based approach to diagnosis, which delays any advance in developing effective early interventions. Past classifications in psychiatry were developed on the implicit assumption of lasting stability. …