Evidence map›Paper›PMID 33123819›Full record

Trial reportPsychopharmacology2020

The effects of caffeine on olfactory function and mood: an exploratory study.

Lorenzo D Stafford, Kaylee Orgill

Open access · hybridAbstract readRandomized Controlled Trial
In one paragraph

Trial report in Psychopharmacology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.

0numbers the graph read from it
0cells of the map it votes in
4citing papers in PubMed
0.4field-weighted citation impact, top 41% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

4 citing papers in PubMed, 6 citations in OpenAlex.

  1. Caffeine Consumption and Rhinologic Symptom Severity.Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery · 2026
    Article
  2. Article
  3. Article
  4. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

2 authors at 1 institution in 1 country.

Lorenzo D StaffordDepartment of Psychology, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK. lorenzo.Stafford@port.ac.uk.ORCID http://orcid.org/0000-0002-8791-204X
Kaylee OrgillDepartment of Psychology, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, PO1 2DY, UK.
University of Portsmouth · GB

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Caffeine has been demonstrated to enhance olfactory function in rodents, but to date, the sparse research in humans has not shown any equivalent effects. However, due to the methodological nature of those human studies, a number of questions remain unanswered, which the present study aimed to investigate. Using a double-blind experimental design, participants (n = 40) completed baseline mood measures, standardised threshold and identification tests and were then randomly allocated to receive a capsule containing either 100 mg of caffeine or placebo, followed by the same olfactory tests and mood measures. Results revealed that despite a trend toward elevated arousal following caffeine for habitual caffeine consumers, there were no changes in odour function. In contrast, for non-caffeine consumers, caffeine acted to enhance odour (threshold) sensitivity but reduce odour identification. Overall, these findings demonstrate a complex profile of effects of caffeine on odour function and, given the evidence from the wider caffeine literature, it is proposed that the effects of caffeine might be limited to older populations.

Indexed as

AdolescentAdultAffectArousalCaffeineDouble-Blind MethodFemaleHumansMaleOlfactory PerceptionSensory ThresholdsYoung AdultCaffeineAdenosineCoffeeOdour identificationOdour thresholdSmellTea

Identifiers

PMID33123819
PMCPMC7683449
OpenAlexW3097627161

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.