Effects
of brief caffeinated-beverage deprivation on
mood, symptoms, and psychomotor
performance
Lane JD
Department of Psychiatry and
Behavioral Sciences,
Duke University Medical
Center, Durham, USA.
The effects of short-term deprivation of
caffeinated beverages on mood, withdrawal
symptoms, and psychomotor performance were
studied in habitual coffee drinkers. Twenty-four
male and female coffee drinkers were tested at
midday (1130-1330 h) under two conditions. On
one day they consumed caffeinated beverages ad
lib prior to testing, and on the other they
remained caffeine abstinent. The order of
treatments was counterbalanced. Mood and
withdrawal symptom reports were collected by
questionnaires. Psychomotor performance was
tested with a computerized test battery.
Caffeinated-beverage deprivation was associated
with decreased vigor and increased fatigue and
with symptoms including headache. No changes in
psychomotor performance were observed. Even
short periods of caffeinated-beverage
deprivation, equivalent in length to missing
regular morning coffee, can produce noticeable
unpleasant caffeine-withdrawal symptoms by the
middle of the day. These symptoms may be a
common side effect of habitual caffeinated
beverage consumption.
CAFFEINE is one of the most commonly used
drugs, but it is not without side effects.
Perhaps the most frequent is the pattern of
physiological withdrawal symptoms that occur
when habitual consumers abruptly stop. The
characteristics and time course of the
withdrawal syndrome appear to be consistent and
are characterized by headache and arousal
deficits that develop in a day or two and last
up to a week with continued abstinence. The
syndrome occurs even in people who consume as
little as 100 mg of caffeine daily, equivalent
to a single cup of coffee. One recent study of
caffeine withdrawal in low to moderate consumers
found that caffeine deprivation for 2 days
produced increases in symptoms of depression and
anxiety, decreases in vigor and friendliness,
and increases in fatigue and confusion.
Deprivation also elicited a variety of specific
symptoms related to irritability, sleepiness and
fatigue, difficulty with thinking and working,
headache, and feeling generally unwell. These
effects can be clinically important because the
symptoms associated with caffeine withdrawal
overlap with medical complaints commonly
reported to physicians.
Most experimental investigations of caffeine
withdrawal symptomatology have involved several
days of caffeine deprivation. Although long
periods of caffeine deprivation provide the
opportunity to observe the full range and
intensity of symptoms as they develop and
resolve over time, such extended deprivation is
relatively uncommon under normal circumstances,
except for the rare individuals who attempt to
quit caffeine consumption "cold turkey." Shorter
periods of deprivation, for example, when a
regular coffee drinker misses his or her normal
morning coffee, would be much more common in
everyday life. Studies suggest that these short
deprivation periods too can lead to cli a y s
ificant withdrawal symptoms, such as headach and
fatigue.
In an earlier study of caffeine effects on
neur endocrine stress reactivity in the work
evironment, assessed mood and withdrawal symptom
in people who were deprived of caffeine
overnight and then eceived either 300 mg of
caffeine or placebo at the start of the workday.
Participants performed their normal work
activities for 4 h and then rated their
experience of the morning. When given placebo,
participants reported higher levels of
sleepiness, lethargy, and headache and a reduced
desire to socialize. They also reported casually
that it was much harder to work and to pay
attention to what they were doing. Simply being
deprived of normal morning coffee appeared to
have clinically significant effects on these
regular coffee drinkers, even after a few hours
of deprivation.
The current study was designed to pursue
this observation and to investigate the effects
of such short-term caffeine deprivation on
withdrawal symptoms and psychomotor performance.
I sought to explore how regular coffee drinkers
would feel during a normal workday morning if
deprived of their regular morning coffee and
whether such deprivation produced cognitive
performance deficits that could affect their
work. Regular coffee drinkers were tested at
midday after mornings when they either consumed
coffee and other caffeinated drinks ad lib or
abstained completely from caffeine. Self-report
questionnaires assessed mood and caffeine
withdrawal symptoms, and a battery of
computerized psychomotor tasks assessed
psychomotor performance. Based on earlier
observations, it was expected that even this
brief period of deprivation would be associated
with detectable withdrawal symptoms and
performance decrements.
DISCUSSION
Periods of experimental caffeinated-beverage
deprivation equivalent to people skipping their
normal morning coffee produced detectable
symptoms of caffeine withdrawal at midday. These
effects were observed both in the POMS measures
of self-rated mood and in the appearance of
specific symptoms that have been associated with
caffeine withdrawal. The pattern of results is
similar to that observed for longer periods of
deprivation and in my earlier ambulatory study
.
The POMS factor for Vigor-Activity
represents a mood of vigorousness, ebullience,
and high energy associated with feeling
cheerful, alert, active, and full of pep. The
POMS factor for Fatigue-Inertia represents a m
of w mess, inertia, and low energy. The
combinatio of reduced vigor and increased
fatigue reported on the PO *S was consistent
with the pattern of reported withdrawal mptoms,
which emphasized decreased levels of arousal as
ociated with difficulty in concentrating.
However, the shorte period of deprivation in our
study was not associated with ircreases in
anxiety or depression, as noted in longer
periods of caffeine deprivation.
It is noteworthy that even this short period
of deprivation produced significant ratings of
headache and flu-like symptoms. On average,
these differences may appear small in magnitude,
but examination of the number of participants
who experienced these particular symptoms
suggests a different interpretation. Only one
person reported headache on the ad lib
consumption day, and the headache was given a
rating of 1 on the O to 3 scale. In contrast, 10
people reported headache during the morning of
deprivation, including 4 who gave their headache
the maximum rating available. No one reported
any flu-like symptoms during ad lib consumption,
but five people did during deprivation, rating
the magnitude as a 1. Thus, even short periods
of caffeinated-beverage deprivation may produce
clinically significant physical symptoms in
regular coffee drinkers. In many respects, these
observations are similar to reports of headache
symptoms during short-term caffeine abstinence
associated with religious fasting and surgical
procedures.
The observed differences in casual blood
pressure (lower when caffeine-deprived) are
consistent with laboratory findings that
caffeine administration is associated with
increases in blood pressure. Our own laboratory
studies have found that a single 250 mg dose of
caffeine raises resting systolic and diastolic
blood pressure by 7-10 mmHg 60 min after
administration. The effects seen here are
consistent with these earlier observations,
given the variability in caffeine dose and
timing in the present ad lib study. They confirm
that ad lib caffeine consumption is associated
with elevated blood pressure compared with
caffeine abstinence, even in habitual coffee
drinkers who should have developed tolerance to
the drug's effects. This finding has
implications for epidemiological studies of
caffeine and cardiovascular disease risk, which
have often collected blood pressure data under
fasting (thus, caffeine-deprived) conditions.
Casual blood pressure in heavy coffee drinkers
is probably underestimated under such
conditions, which could lead to false negative
results regarding the association of coffee
drinking and elevated blood pressure and
misleading conclusions about the coronary
disease risks associated with coffee or
caffeine. Coffee's potential as a hypertension
and coronary disease risk factor may need to be
reevaluated.
Although anecdotal reports from participants
and subjective measures of mood and symptoms
suggested the presence of diminished cognitive
capacity and functional impairment during
caffeinated beverage deprivation, no deficits in
psychomotor task performance were found. Similar
negative results are common in the decades of
research into caffeine's effects on performance,
where comparisons of caffeinated and
caffeine-deprived conditions yield performance
differences that are typically small and
capricious. The battery of tasks covered a
variety of psychomotor functions from simple to
complex. Only the serial memory task yielded
possible evidence of impairment, and this was
compromised by an order interaction. Given the
changes in mood and symptoms, performance
deficits caused by functional impairment or
decreased motivation would be expected. It is
possible that the specific tasks of the present
study do not tap the dimensions of cognitive
performance affected by caffeine deprivation.
Furthermore, these tasks were all of relatively
short duration, and participants may have been
able to push themselves to overcome any
withdrawalrelated deficits. Recently Streufert
and colleagues reported that caffeine
deprivation produced significant deficits in
managerial performance measures collected during
long, complex work simulations. Perhaps longer
periods of more naturalistic cognitive and
work-related tasks will provide a clearer
demonstration of performance deficits in future
studies.
The attempt to investigate whether heavier
consumers experienced stronger withdrawal
symptoms yielded some supporting evidence of
correlation. This effort was hindered by the
relatively small sample size, but relationships
were observed for at least some of the symptoms.
Other studies have demonstrated that deprivation
can produce symptoms of withdrawal even in
people who consume light to moderate amounts of
caffeine, even as low as 100 mg (one cup of
coffee) per day. Although this may be true, our
preliminary evidence suggests that the
experience of withdrawal symptoms may be more
intense in people who habitually consume larger
amounts of caffeine.
Compliance with instructions for caffeine
abstinence was not confirmed objectively by
measures of caffeine level in plasma or saliva.
However, the possibility that some participants
failed to maintain abstinence in the deprivation
condition is not a serious limitation.
Participants were asked directly about their
compliance with instructions for abstinence or
diary record-keeping, and we have no reason to
suspect their reports. Moreover, scattered
noncompliance with the abstinence condition
would not likely yield the significant
differences between ad lib and deprived
conditions observed here. Rather, it would tend
to increase the variability of scores in the
deprived condition, making it even more
difficult to detect differences between the
two.
The present study was intended to simulate
natural conditions of caffeinated beverage
consumption and deprivation in the real world.
This decision had several implications for the
outcome. Because participants were asked to
consume ad lib, caffeinated beverages, and
presumably caffeine dose, varied both in amount
and timing. Variations in caffeine dose probably
contributed to variability among participants in
scores for mood, symptoms, and performance on
the ad lib day, which may have prevented
detection of differences in some variables. In
contrast, expectations about the effects of
caffeine deprivation may have contributed to the
observed differences in mood and symptoms, which
were based on retrospective self-reports.
Participants were not blind to treatment
condition, because they maintained their own ad
lib or abstinent status, and beliefs about
caffeine withdrawal symptoms could have colored
their reports. Moreover, the disruption of other
normal routines that was caused by the
experimental demands for caffeinated beverage
deprivation may have had a negative effect on
mood during the morning. A naturalistic study
such as this cannot control these extraneous
factors. As a result, observed differences
reflect more than the presence or absence of
caffeine. However, they do represent the broader
experience of caffeinated-beverage deprivation,
which naturally includes the expectations and
the changes in routine, and which was the
subject of the investigation.
In many respects, the present study confirms
what most regular coffee drinkers would probably
admit: they suffer when they don't get their
regular morning coffee. However, investigation
of the clinically significant effects of even
brief periods of deprivation is worthwhile
because these symptoms (e.g., headache, fatigue,
etc.) are such common complaints presented to
physicians and may be otherwise difficult to
explain. Moreover, given the widespread use and
increasing popularity of coffee, it is worth
noting that habitual caffeine consumption is not
without a potential cost to well-being. At the
very least, habitual coffee drinkers run the
risk of misery when they cannot get their
regular cup.
Aloe F Yawning.
Arq Neuropsiquiatr 1994; 52; 2; 27-36`
Beale MD. Murphree
TM. Excessive yawning and SSRI therapy. Int.
J. Neuropsychopharmacol. 2000; 3: 275-276.
Bertschy G;
Vandel S; Sechter D; Bizouard P
Bâillements et excitation sexuelle sous
clomipramine. Place des mécanismes
serotoninergiques. A propos of 2 cases Encephale
1991; 17; 6; 515-7
Cohen AJ.
Fluoxetine-induced yawning and anorgasmia
reversed by cyproheptadine treatment. J. Clin.
Psychiatry 1992: 53: 174.
Goldberg RL
Sustained yawning as a side effect of imipramine
Int J Psychiatry Med 1983-84; 13; 4; 277-80
Gutierrez-Alvarez
AM Do your patients suffer from excessive
yawning? Acta Psychiatrica Scandinavica
2007;115(1)-80-81
Modell JG.
Repeated observation of yawning, clitoral
engorgement, and orgasm associated with
fluoxetine administration. J. Clin.
Psychopharmacol. 1989; 9: 63-65.
Pae CU, JJ
Kim et al Injured temporomandibular joint
associated with fluoxetine-monotherapy-induced
repeated yawning Gen Hosp Psychiatry 2003; 25;
3; 217-218
Prescrire
Bâillements : parfois un effet
indésirable d'un médicament La
Revue Prescrire 2005; 25 ; 265; 676
Sommet
A et coll. "Drug-induced yawning:a review of
the French pharmacovigilance database" 9e
congrès annuel de la
Société française de
pharmacologie; 26e journées de
pharmacovigilance, Bordeaux : 26-28 avril 2005.
Fundamental Clin Pharmacol 2005; 19 (2):227
(abstract P123).
Tesfaye Y,
Lal S Hazard of yawning Canadian Med Assoc J
1990; 142; 1; 15 & 1991;1 45;12; 1560
