from the ClinicalTrials.gov record
Major depressive disorder (MDD) is the current leading cause of disability worldwide and adolescence is an especially vulnerable period for the onset of depression. Non-pharmacologic approaches are particularly attractive as treatment of adolescent depression due to the elevated risks of side effects related to the use of psychotropic drugs during development. A recent meta-analysis detected a positive and significant effect of non-deceptive placebos (open-label placebo, OLP) for a series of clinical conditions, including adult depression. To the investigators' knowledge, no studies of OLP have been conducted in depressed adolescents to date, although placebo response rates in adolescent depression are especially high, accounting for over 80% of the actual response to antidepressant treatment. The study's main objective is to estimate the effectiveness and understand the mechanism of OLP in depressed adolescents. The central hypothesis is that the mechanism by which OLP exerts its action in adolescent depression is by forming a positive expectation, which activates endogenous mu-opioid receptor (MOR)-mediated neurotransmission in a network of regions implicated in emotion, stress regulation, and the pathophysiology of MDD, namely, the anterior cingulate cortex (ACC) - striato - amygdalo - thalamic network. The hypothesis has been formulated on the basis of published research and preliminary data. The investigators will test the hypothesis by performing structural and functional neuroimaging in 60 untreated 13-18 year-old adolescents with mild to moderate depression. The proposed research is significant, because it is expected to elucidate the mechanism of action of OLP and advance the understanding of the neural underpinnings of positive expectations in adolescent depression.