Are child-, adolescent-, and adult-onset depression one and the same disorder?

This paper reviews prior research studies examining neurobiological correla tes and treatment response of depression in children, adolescents, and adul ts. Although theta are some similarities in research findings observed acro ss the life cycle, both children and adolescents have been found to differ fram depressed adults on measures of basal cortisol sedation, corticotropin stimulation post-corticotropin releasing hormone (CRH) infusion, response ra several serotonergic probes immunity indices, and efficacy; of a tricycl ic medications. These differences are proposed to be doe to 1) developmenta l factors, 2) stage of illness factors (e.g., number of episodes, total dur ation of illness), or 3) heterogeneity in clinical outcome (e.g., recurrent unipolar course vs. new-onset bipolar disorder). Relevant clinical and pre clinical studies that provide support for these alternate explanations of t he discrepant findings are reviewed, and directions for future research are discussed. To determine whether child, adolescent-, and adult-onset depres sion represent the same condition, it is recommended that researchers II us e the same neuroimaging paradigms in child, adolescent and adult depressed cohorts; 2) carefully characterize subjects' stage of illness; and 3) condu ct longitudinal clinical and repeat neurobiological assessments of patients of diffrrent ages at various stages of illness. In addition careful attent ion to familial subtypes (e.g., depressive spectrum disorders vs. familial pure depressive disorders) and environmental factors; (e.g., trauma history ) are suggested for future investigations, (C) 2001 Society of Biological P sychiatry.