Adults 25 to 44, female only, with Anhedonia or Depression. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Non-social (Monetary) Reward Response (Reward Learning and Sensitivity)Primary· Baseline and post-injection (2.25 hrs)
Implicit reward learning and sensitivity to monetary reward is assessed with the probabilistic reward task (PRT) a behavioral computer task; change in the magnitude of response bias from baseline to post-injection is the outcome measure. More positive response bias indicates a bias towards the more frequently reward stimuli (a better outcome); more negative response bias indicates a bias towards the less frequently reward stimuli (a worse outcome). This is not a standardized scale with minimum and maximum values. Response bias is calculated using a formula from signal detection theory and is a
Motivation for monetary reward is assessed with a 10-minute version of the Effort Expenditure for Rewards Task (EEfRT), a behavioral computer task; change in the amount of hard trials chosen (relative to total trials) from baseline to post-injection is the outcome measure. The task is analyzed using generalized estimating equations (GEE) with a binary outcome; outcome values at each timepoint therefore range from 0 to 1, with higher numbers indicating higher motivation (a better outcome). The predictor for the GEE model is a time (coded as 0 and 1) by condition (coded as 0 and 1) interaction t
Sensitivity for monetary reward is assessed with a 10-minute version of the Effort Expenditure for Rewards Task (EEfRT) a behavioral computer task, tested as the strength of the association between increases in potential monetary reward for hard trials and selection of hard (vs) easy trials during the task. This is tested using generalized estimating equations, with condition (LPS vs. placebo) by time (pre vs post-injection) by reward magnitude (ranges from $1-$4.12) predicting hard (vs easy) trial choice. More positive values indicate higher reward sensitivity ( a better outcome), and lower v
Group
Value
95% CI
Endotoxin
-.0525937
-.1125722 – .0073848
Placebo
.0521303
.0032571 – .1010036
General Social Reward Response (Reward Sensitivity Via Emotional Dot Probe)Primary· Baseline and post-injection (2.7 hrs)
Sensitivity to general social reward cues (i.e., response to positive emotional faces) assessed as positive attentional bias with an emotional dot probe task. Attentional bias is assessed by measuring reaction times to targets that appear in the same location as emotional (e.g., happy faces) versus neutral cues (e.g., neutral faces).
Outcomes are change from baseline to post-injection in attentional bias towards positive vs neutral faces. Higher positive attentional bias scores indicate higher sensitivity to reward; negative attentional bias score indicate less sensitivity to reward. A score
Group
Value
95% CI
Endotoxin
11.85463
± 18.61149
Placebo
5.806407
± 38.32138
General Social Reward Response (Reward Sensitivity Via Face Morphing Task)Primary· Baseline and post-injection (2.8 hrs)
Sensitivity to general social reward cues (i.e., response to positive emotional faces) assessed as positive emotion detection with a face morphing task. The outcome is the absolute change from baseline to post-injection in the percent of accurate responses. Higher accuracy is an indicator of higher sensitivity to reward and lower accuracy is an indicator of lower sensitivity to reward.
Group
Value
95% CI
Endotoxin
.0092593
± .0190538
Placebo
.0657895
± .0185456
General Social Reward Response (Social Reward Motivation)Primary· Baseline and post-injection (2 hrs)
Motivation for general social reward is assessed via self-report; participants rate their desire to engage in 3 different activities, one of which is social, on a 1 (not at all) to 10 (extremely) Likert scale.; change in desire for the social activity from baseline to post-injection is the outcome variable. Higher values indicate higher motivation.
Group
Value
95% CI
Endotoxin
-2.94
± 3.40
Placebo
-.29
± 1.65
Depressed Mood Subscale of the Profile of Mood States (POMS)Secondary· Hourly, from pre-injection (T0) to 9 hours later (T9)
The Depressed Mood Subscale of the POMS is a self-reported assessment of depressed mood in which subjects rate severity of depressed mood using a visual analog scale from 1 to 10 (10 being most severe). Each timepoint is scored and analyses examine the temporal profile of change with assessment every hour. The outcome reported below is the mean score at 2-hours post-injection, which is when the response to endotoxin is known to peak. Higher values indicate more depressive symptoms.
Group
Value
95% CI
Endotoxin
6.939871
± 1.952918
Placebo
2.680794
± 1.762826
Sponsor's own description
Compelling evidence indicates inflammation plays a role in depression, but potential mechanisms linking inflammation to depression, such as dysregulated reward processing, are poorly understood. This study comprehensively evaluates effects of inflammation on reward across dimensions (e.g., anticipating versus receiving a reward) and types (e.g., money vs. smiling faces) in younger and older women. Characterizing how inflammation shapes the dynamic and multidimensional reward system, and how this may differ by age, may give insight into risk factors for depression and help identify critical points for intervention.
Publications & conference data
2 peer-reviewed publications reference this trial (live from Europe PMC):
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by University of California, Los Angeles
Last refreshed: 27 January 2026
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03848715.