Preventing mental disorders: the challenge ahead

Abstract

Mental disorders, defined by alterations in thinking, mood, or behavior, are currently understood as the expression of deviant processes of brain development, precipitated by the conjoint effect of genetic predisposition, biological and environmental risks, which begin early in life and have last-longing effects [1, 2]. It is very likely that alterations in thinking, mood or behavior, as described by current diagnostic criteria, are late manifestations of deviant neurodevelopmental processes that are no longer sensible to remediation [3]. This would explain why available treatments for mental disorders are not curative. A good example of the persistence and severity of mental disorders and the limitations of currently available treatments is presented by Wachtel et al. in this issue [4]. To reduce the enormous burden caused by mental disorders, a logical strategy is to direct efforts to preventive measures, impeding deviations of neurodevelopmental processes or addressing them at early stages, when they are still sensible to modification [5, 6]. In fact, preventive interventions, such as hand washing and vaccines have played a crucial role in the history of medicine, and are clearly responsible for striking positive outcomes. However, prevention has not been a priority in the field of psychiatry until recently [6]. Nevertheless, a consistent body of evidence have accumulated over the past decades supporting the efficacy and effectiveness of preventive interventions that target a whole population (universal interventions) or individuals who are at risk of developing a disorder or who already present minimal symptoms (selective and indicated interventions, respectively) [6]. One example is a prenatal and early childhood nurse home visitation program for new mothers that reduced the incidence of antisocial behavior and use of substance in their offspring 15 years after the intervention [7]. Another example is the study by McArdle et al. in this issue [8] reporting the 2 and 3-year outcomes of a school-based intervention for children at risk or with behavioral or emotional difficulties in reducing general psychopathology. Children were identified by their teachers, and were subsequently randomized to either a drama group therapy or to a group of curriculum studies, which were delivered in weekly sessions over a school term. The investigators detected a decline in psychopathology as measured by teachers for the sample as a whole and low scores were maintained during time, with no effect reported by the subjects and their parents. The empirical evaluation of preventive measures faces several conceptual and methodological challenges. Universal strategies are expensive and it is not clear whether they are cost-effective as a group of interventions for preventing specific mental disorders. Selective and indicated interventions seem to be more cost-effective, but also offer challenges (for an excellent review on the subject, see [9]). One of the several challenges is to identify the deviant neurodevelopmental processes involved in the pathophysiology of the disorder, and have a specific intervention that addresses them. Besides that we need to reach at-risk children, who are not in the clinical settings, but at the community and schools. Teachers play a major role in this task, as the study by Lundervold et al. in this issue shows us [10]. Cognitive processing speed is an important aspect of intellectual ability, and seem to mediate the age-related G. V. Polanczyk (&) Department of Psychiatry, University of Sao Paulo Medical School, National Institute of Developmental Psychiatry for Children and Adolescents (INCT-CNPq), Rua Dr Ovidio Pires de Campos 785, Sao Paulo, SP 05403-010, Brazil e-mail: gvp@usp.br