Mechanisms of Antidepressant Non-Response in Late-Life Depression

Completed · Not applicable · Has a placebo group

Conditions studied: Major Depressive Disorder

In brief

This project seeks to elucidate the mechanisms by which antidepressant medications have limited efficacy in Late Life Depression (LLD) in order to develop new treatment interventions for this prevalent and disabling illness. Investigators hypothesize that the presence of executive dysfunction (ED),which is common in depressed adults over 60, impairs the ability to form appropriate expectancies of improvement with antidepressant treatment. Greater expectancy has been shown to improve antidepressant treatment outcome and is hypothesized to be a primary mechanism of placebo effects. Moreover, white matter hyperintensities (WMH) on magnetic resonance imaging (MRI) are more prevalent in patients with LLD compared to healthy controls. It has been argued that WMH contribute to the pathogenesis of LLD with ED and decrease the efficacy of antidepressant medications by disrupting connections between prefrontal cortical (PFC) and subcortical structures. Vascular lesions to white matter tracts may also compromise the pathway by which expectancy-based placebo effects influence depressive symptoms. Expectancies reflect activation in PFC areas that may improve depressive symptoms by modulating the activity of subcortical regions subserving negative affective systems (i.e., amygdala) as well as those important in reward and hedonic capacity (nucleus accumbens and ventral striatum). Thus, LLD patients with ED and WMH may sustain a "double-hit" to their ability to experience placebo effects in antidepressant treatments: ED diminishes the ability to generate appropriate treatment expectancies, while WMH disrupt the physiologic pathways by which expectancies lead to improvement in depressive symptoms.

Key facts

Study ID
NCT01931202
Run by
New York State Psychiatric Institute
People needed
138
Starts
2014-02-19
Expected to finish
2020-01-17
Last updated by the study team
2020-07-02

Who can join

Age: 60 and older, up to 90. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

You may not qualify if…

Where it is running

Full record on ClinicalTrials.gov

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