Are increased weight and appetite useful indicators of depression in children and adolescents?

During childhood and adolescence, physiological, psychological, and behavioral processes strongly promote weight gain and increased appetite while also inhibiting weight loss and decreased appetite. The Diagnostic and Statistical Manual-IV (DSM-IV) treats both weight-gain/increased-appetite and weight-loss/decreased-appetite as symptoms of major depression during these developmental periods, despite the fact that one complements typical development and the other opposes it. To disentangle the developmental versus pathological correlates of weight and appetite disturbance in younger age groups, the current study examined symptoms of depression in an aggregated sample of 2307 children and adolescents, 47.25% of whom met criteria for major depressive disorder. A multigroup, multidimensional item response theory model generated three key results. First, weight loss and decreased appetite loaded strongly onto a general depression dimension; in contrast, weight gain and increased appetite did not. Instead, weight gain and increased appetite loaded onto a separate dimension that did not correlate strongly with general depression. Second, inclusion or exclusion of weight gain and increased appetite affected neither the nature of the general depression dimension nor the fidelity of major depressive disorder diagnosis. Third, the general depression dimension and the weight-gain/increased-appetite dimension showed different patterns across age and gender. In child and adolescent populations, these results call into question the utility of weight gain and increased appetite as indicators of depression. This has serious implications for the diagnostic criteria of depression in children and adolescents. These findings inform a revision of the DSM, with implications for the diagnosis of depression in this age group and for research on depression.