# Dynamics of Inflammation and its Blockade on Motivational Circuitry in Depression

> **NIH NIH R01** · EMORY UNIVERSITY · 2020 · $414,013

## Abstract

Project Summary
Motivational anhedonia–a subset of anhedonic symptoms involving dopamine-linked impairments in effort-
based decision-making, reward anticipation and reinforcement learning–are common in psychiatric disorders
such as major depression, and are notoriously difficult to treat. In recent years, these symptoms have been
associated with alterations in dopaminergic corticostriatal circuitry, yet the underlying causes of this circuit
dysfunction remain unknown. One candidate mechanism is inflammation; increased inflammatory cytokines
have been reliably found in depressed patients, and administration of inflammatory cytokines or cytokine
inducers has been shown to foment depressive symptoms of apathy, anhedonia and fatigue. In addition,
inflammatory cytokines have been found to disrupt dopamine synthesis, alter basal-ganglia metabolism, and
blunt striatal responsivity during reward anticipation. To date, however, the majority of data supporting the
relationship between cytokines and symptoms in patients with major depression and other disorders is
correlational in nature, and thus alternative experimental strategies are required to elucidate causal
relationships. One strategy is to block inflammatory cytokines in a sample of depressed patients with high
inflammation so as to determine which symptom domains are most affected and through which molecular
pathways. Previously, we found that the TNF antagonist infliximab (a “biologic” monoclonal antibody that
selectively inhibits TNF) selectively reduced symptoms of motivational anhedonia, but only in depressed
patients with high inflammation as reflected by plasma c-reactive protein (CRP) of at least >3mg/L.
Unfortunately, not all patients in this sample exhibited high inflammation, and these associations must
therefore be considered preliminary, albeit promising. More critically, this study was unable to address target
engagement at the level of neural circuitry. Building off of these initial data, the current study will assess
neuroimaging measures of corticostriatal circuitry before and after a placebo-controlled pharmacologic
blockade of inflammation in 80 depressed patients (n = 40 per group) recruited to ensure high levels of
peripheral inflammation (CRP > 3mg/L). Primary aims are to evaluate whether 1) corticostriatal function during
reward motivation and anticipation are associated with change in peripheral inflammation following
pharmacologic blockade relative to placebo 2) the temporal dynamics of change in inflammation, gene-
expression, reward motivation and reinforcement learning behavior and motivational symptoms assessed at
baseline, and 24 hours, 3 days, 1 week and two weeks post infliximab infusion, and 3) test an integrative multi-
level path model to determine whether change in corticostriatal circuitry following inflammation blockade
mediates the relationship between change in inflammation and change in motivational anhedonia symptoms.
These data will provide further valida...

## Key facts

- **NIH application ID:** 9917858
- **Project number:** 5R01MH108605-05
- **Recipient organization:** EMORY UNIVERSITY
- **Principal Investigator:** Michael Tilghman Treadway
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $414,013
- **Award type:** 5
- **Project period:** 2016-07-20 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9917858

## Citation

> US National Institutes of Health, RePORTER application 9917858, Dynamics of Inflammation and its Blockade on Motivational Circuitry in Depression (5R01MH108605-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9917858. Licensed CC0.

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