Available online at:
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J Camosun Psyc Res. (2019). Vol. 1, pp. 12-19.
Submitted April 2019; accepted 16 May 2019.

The effect of CBD ingestion on anxiety.
Author: Kara Solecki*
Supervising Instructor: Michael Pollock, Psyc 245 (“Drugs & Behaviour”)
Department of Psychology, Camosun College, 3100 Foul Bay Road, Victoria, BC, Canada V8P 5J2
*Corresponding author email: ksolecki5@gmail.com

ABSTRACT
Anxiety disorders are a prevalent mental health concern, for which current anxiolytic
medications help to alleviate symptoms of, though often coincide with unwanted side effects.
The present study investigated the relationship between cannabidiol (CBD) ingestion (in mL)
and anxiety in longitudinal baseline conditions as well the effect in an experimental
manipulation, measured using a mood scale and by heart rate. It was hypothesized that CBD
ingestion would lead to a decrease in both self-reported and physiological anxiety. The results
supported the hypotheses. These results are discussed in terms of the important implication that
CBD does appear to have an anxiolytic effect, possibly without the harmful side effects seen in
other interventions.
1. Introduction
Generalized social anxiety disorder
(SAD) is a prevalent disorder with
symptoms that make various aspects of dayto-day life very difficult for those who suffer
the condition. Further, SAD seldom resolves
itself without treatment, and yet, many
people who undergo treatment suffer from
subsequent side effects from their drug
therapy (Bergamaschi et al., 2011). As such,
alternative pharmacological interventions
have recently been researched for the use in
SAD treatment. One such alternative
includes the use of cannabidiol (CBD), a
cannabinoid, which is a constituent of the
Cannabis plant that has been proven to have
anxiolytic effects in both animals and human
(Crippa et al., 2011).
Many studies that have researched
the effects of CBD on anxiety have found
that CBD causes a decrease in subjective

anxiety, but the findings regarding the
effects on physiological anxiety have been
varied (Bergamaschi et al., 2011; Crippa et
al., 2011). An example of such an
experiment was conducted by Bergamaschi
et al (2011). This study researched the
subjective and physiological effects of CBD
on anxiety using a randomized betweensubject, double blind design wherein half of
participants ingested CBD, half of
participants ingested a placebo and all
participants performed an anxiety-inducing
task, simulated public-speaking, and
subsequent levels of anxiety were recorded
using mood scales and various physiological
measures (Bergamaschi et al., 2011). The
researchers found that, on average, treatment
with CBD prior to the speech task
significantly reduced anxiety, while the
placebo group displayed high levels of
anxiety. This study measured anxiety with
the Visual Analogue Mood Scale (VAMS)
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and three physiological measures; skin
conductance, arterial blood pressure, and
heart rate.
The present study involved selfmeasured baseline measurements and a blind
experimental study. During the baseline
period, correlations were measured between
CBD ingestion and self-reported anxiety,
which was measured using the Tension item
in the Profile of Mood States (POMS) scale,
and CBD ingestion and physiological
anxiety, measured using heart rate. The
present experiment compared levels of
physiological anxiety, measured using heart
rate, using a blind procedure in which CBD
was ingested when mixed with orange juice
versus when orange juice was consumed on
its own. Based on previous research
demonstrating the anxiolytic effect of CBD,
during the baseline methods, it was
hypothesized that as CBD ingestion
increased, both psychological and
physiological anxiety would decrease. In the
present experiment, it was expected that
CBD ingestion would decrease heart rate.
2. Methods
2.1 Participants
The baseline methods and experiment
used a single participant. This participant
was a 24-year-old female psychology
student from Camosun College with high
levels of anxiety.
2.2 Materials and Apparatus
The materials used in this study consisted
of 12.5mg/mL of CBD oil (Sun Irisa
Cannabis, High Park Company Ltd, ON,
Canada) and orange juice (Simply Orange,
Minute Maid Canada Inc., Toronto, ON,
Canada). Additionally, during the baseline
methods, the Tension item is the POMS

scale was used to measure subjective levels
of anxiety. Tension is calculated by
summing the scores from 9 adjectives, each
of which is awarded a score from 0 (“Not at
all”) to 4 (“Extremely”), determined by how
one subjectively feels at the time of the
questionnaire (See Appendix A for copy of
POMS scale, modified to include only items
that contribute to Tension score. See
Appendix B for scoring methods).
2.3 Procedure
The participant measured the amount of
CBD ingested (in mL) over a two-week
baseline period by recording in a diary the
times and amount of CBD (in mL) ingested
each day. During this baseline period,
tension was recorded in a diary using the
POMS Scale item 30 minutes before going
to bed each night over the 2-week baseline
period, regardless of whether or not CBD
was ingested. During that same period,
physiological anxiety was measured using
the participant’s heart rate 45 minutes before
going to bed each night, over the two-week
baseline period, regardless of whether or not
CBD was ingested.
During the experiment, the CBD
ingestion was manipulated on experimental
days by ingesting 0.75 mL (CBD
12.5mg/mL) of CBD oil mixed in one glass
of orange juice. The control condition, used
to compare, involved drinking one glass of
orange juice without any CBD. In order to
use a blind procedure for these
manipulations, the participant’s roommate
prepared the beverages in a separate room
from the participant so that the participant
was unaware of whether the juice contained
the CBD oil during any given trial. The
roommate recorded which method was used
on which date, which was not analyzed until
all of the data was collected. It was expected
that the orange juice would mask any taste
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differences between conditions. The order of
conditions was randomly assigned each day
by the roommate by randomly picking a
piece of paper from a pile of 12 pieces of
paper. Prior to data collection, “CBD” was
written on 6 pieces of paper and “orange
juice” was written on 6 other pieces of paper
to represent the two conditions of this study
(“CBD” = Experimental condition, “orange
juice” = Control condition) and to indicate
which beverage the roommate was required
to prepare on any given trial. Heart rate was
quantitatively measured as number of heart
beats per minute, and was measured once
each day for 6 days per condition (12 days in
total). For each day of the experiment, in
both the Experimental and Control
condition, the participant measured their

heart rate 60 minutes after drinking the
orange juice.
3. Results
A strong, negative, linear relationship
was found between the amount of CBD
ingested and physiological anxiety,
measured by heart rate, during the baseline
measurements. The correlation for this
relationship, r = -0.85, was statistically
significant, p = 0.00, suggesting that these
two variables are strongly related (see
Figure 1 and Table 1).
A moderate, negative, linear
relationship was found between the amount
of CBD ingested and self-reported anxiety,
measured using the POMS scale, during the
baseline measurements. The correlation for
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statistically significant, t = 4.53, p = 0.001,
suggesting that CBD ingestion does reduce
heart rate (see Figure 3), which is a
frequently used physiological indicator of
anxiety.
4. Discussion

this relationship, r = -0.68, was statistically
significant, p = 0.005, suggesting that these
two variables are modestly related (see
Figure 2 and Table 1).
The level of significance set in this
experiment was .05. The mean heart rate
during the Experimental condition was
79.33 (SD = 3.14) and the mean heart rate
during the Control condition was 86.67 (SD
= 2.42) (see Table 2). These data were
analyzed using a t-test and the results were

The hypotheses under investigation in the
current study, that as CBD ingestion
increases, physiological anxiety would
decrease and as CBD ingestion increases,
self-reported anxiety would decrease, were
supported by these findings.
The current results are consistent with
many other studies that demonstrate the
anxiolytic effect of CBD in both
psychological and physiological measures
(Bergamaschi et al., 2011; Crippa et al.,

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finding. Finally, these findings are
particularly important due to the
effectiveness of the use of CBD as an
anxiolytic intervention without the reported
side-effects of other treatments
(Bergamaschi et al., 2011).
References

2011). Further, these results specifically
demonstrate a statistically significant
relationship between CBD ingestion and
heart rate, which has been inconsistent in
previous studies (Zuardi, Cosme, Graeff, &
Guimaraes, 1993). However, limitations of
this study include the number of participants
used; future studies should attempt to
replicate the finding that CBD ingestion
causes a decreased heart rate using more
participants in order to further validate this

Bergamaschi, M. M., Queiroz, R. H.,
Chagas, M. H., de Oliveira, D. C., De
Martinis, B. S., Kapczinski, F., . . .
Crippa, J. A. (2011). Cannabidiol reduces
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anxiety disorder: A preliminary report.

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Journal of Psychopharmacology, 25(1),
121-130. doi:
10.1177/0269881110379283
Zuardi, A. W., Cosme, R. A., Graeff, F. G.,
& Guimaraes, F. S. (1993). Effects of
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Appendix A

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Appendix B

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