Antidepressants and adolescent brain development

Future Neurol. (2011) 6(6), 783–808 10.2217/FNL.11.51 © 2011 Future Medicine Ltd The idea that the developing brain is a highly malleable structure that is particularly vulnerable to environmental toxins has long been recognized. Both the preclinical and human literature has repeatedly demonstrated that prenatal and early life exposure to a variety of drugs can have untoward and lasting consequences on brain development (see [1–3] for reviews). Examples include methamphetamineinduced disturbances in dopaminergic regions [4] and the widespread structural and functional abnormalities apparent in individuals with fetal alcohol spectrum disorders [5]. The last decade has brought increasing recognition that this period of vulnerability is not limited to early life. Instead, the brain continues to undergo extensive reorgani zation and growth during childhood and adolescence and into early adulthood, rendering it susceptible to environmental influences throughout these periods. While much of the literature has focused on the characteristics of the adolescent brain in terms of vulnerability to addiction and susceptibility to the toxicity of alcohol, nicotine and illicit drugs [6–12], there is increasing recognition that the susceptibility of this period also extends to the effects of psychotropic drugs, including antidepressants, stimulants and antipsychotics [13–15]. Children and adolescents are not little adults, and often display different behavioral and neural responses to pharmacological manipulations. However, there is debate on whether the malleability of the brain during adolescence is a window of opportunity in which treatment might allow greater potential for adaptive recovery or whether exposure to psychotropic medications may have enduring negative effects [14]. Given the recent increases in the prescription of psycho tropic drugs to children and adolescents [16] and the explosion in the diagnosis of psychiatric disorders in this population [17,18], a detailed knowledge of the immediate and long-term effects of such drug treatment is vital to informing clinical practice. In this article, we review and discuss the current knowledge on both the immediate and long-term neural effects of antidepressant treatment during late childhood and early adolescence.