Reciprocal longitudinal associations between pain and depressive symptoms in adolescents

Background: Elevated depressive symptoms are common in youth with chronic pain, and pain symptoms are frequent in adolescents with depressive disorders. While studies have identified concurrent associations between pain and depression over time in youth, it is unclear how change in one symptom impacts change in the other symptom. Methods: This three-time point 12-month longitudinal study examined reciprocal associations among pain and depression in a clinical sample of adolescents (12-18) diagnosed with chronic pain (n = 55) or a depressive disorder (n = 40). Mixed-effects multivariate models were used to test if changes over a preceding time interval predicted symptom severity at subsequent time points. Study group, age, sex, race, baseline pain intensity and baseline depressive symptoms were included as covariates. Results: Generalized estimating equations revealed that pain and depressive symptoms were significantly associated over time (β = 1.54; p < 0.001). As hypothesized, changes in pain were associated with subsequent depressive symptoms (β = 1.16; p < 0.001). Conversely, changes in depressive symptoms predicted subsequent pain (β = 0.026; p < 0.05), but with a weaker association. In the model predicting pain, an interaction between depressive symptoms and study group emerged (β = -0.02; p < 0.05), with change in depressive symptoms having the greatest impact on pain in the depressed sample. Conclusions: Findings extend previous adult research to an adolescent sample showing changes in pain intensity are predictive of subsequent depressive symptoms. In comparison to adult data, changes in depressive symptoms had less impact on subsequent pain in youth. Future research can examine how targeting persistent pain may also aid the treatment of depressive symptoms in adolescents.