Critical Appraisal of a Study on the Effects of Yoga on Depression and Anxiety in Women

This critical appraisal analyzes a study on the effects of yoga on depression and anxiety in women. The study found that yoga can significantly reduce the perceived level of stress and anxiety among women who suffer from anxiety disorders. The article discusses the summary of the study, measurement validity and reliability, internal and external validity, and recommendations to overcome the threats of internal and external validity.

Running head: CRITICAL APPRAISAL
CRITICAL APPRAISAL
Name of the Student
Name of the University
Author Note

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Summary of the article
Yoga is frequently regarded as an important stress management tool the can be used
to assist individuals during alleviating mental health condition like depression and anxiety
disorders (Sharma, 2014). The study conducted by Javnbakht, Kenari and Ghasemi (2009)
mainly aims to evaluate the influence of yoga during the process of relieving the symptoms
of complex mental health problems like depression and anxiety. The main focus group
selected by the author for this analysis are the women who were referred to a yoga clinic
during the tenure of July 2006 to July 2007. The selected group of participants were
randomly assigned in two different groups one is placebo group (n= 31) and another one is
experimental group (n = 34). The experimental group participated in weekly yoga classes two
times per week for tenure of 90 minutes for duration of 2 months. The control or the placebo
groups did not receive yoga. Both the groups are evaluated after 2 months with the help of
personal information questionnaire along with Beck and Speilberger tests. The analysis of the
result highlighted that prevalence of depression in the test group during pre-yoga condition
was 12.82 +/- 7.9 and post yoga condition was 10.70 +/- 6.04. The difference in the
depression level was however statistically insignificant with p = 0.13. However, when the
experimental group was compared with the control or the placebo group, it was found that
women who participated in the yoga classes showed a prominent decrease in the level of state
anxiety (p= 0.03) and trait anxiety (p< 0.001). The perceptive representation of the test
highlighted that the after 2 months of yoga, the level of depression of the experimental group
decreased by 11.8% (previously it was 44.1%) and was found to be 32.3%. Thus from the
extracted results, the authors concluded that the participation in yoga classes for 2 months can
cause significant reduction in the perceived level of stress and anxiety among the women who
suffer from anxiety disorders (Javnbakht, Kenari & Ghasemi, 2009). The authors further

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recommended that yoga can be regarded as an alternative non-pharmacological therapy for
the treatment of anxiety related disorders.
Summary of measurement, Validity and Reliability
The authors of the study included only the female patient within the study. Thus the
study scores less in the domain of sample validity. According to Krupnikov and Levine
(2014), sample validity ensures that selected group of sample covers a broad range within the
concept under the study such that, the result is replicable and is valid over a wide range of
sample. However, selection of only female participants in the study highlighted the “expert”
bias. According to Nolen-Hoeksema and Hilt (2013) the level of stress and depression differs
with age, gender and occupation. However, Javnbakht, Kenari and Ghasemi (2009) only
included female participants who documented psychological disorders or are under doctor’s
recommendation for taking yoga as a therapy for recovery.
The Javnbakht, Kenari and Ghasemi (2009) used 21-ietm Beck depression inventory
questionnaires for ascertaining depression among the selected group of participants.
According to Wang and Gorenstein (2013), Beck and Depression Inventory (BDI)
questionnaires asses the depressive symptoms of the patients and rates their intensity on the
scale from 0 to 3 (total score provided is 0 to 63). Higher the BDI score, greater is the
indication of the depressive mood. 0 to 9 score is regarded as depressive mood, 10 to 18 as
low depressive mood, 19 to 20 moderate depressed mode and 30 to 63 score is the indicators
of severely depressed mood. Thus it can be said that single tool, BDI score is used to analyze
the depression score of the selected groups of the participations and hence the study is
reliable. According to Noble and Smith (2015), reliability is the degree to which an
assessment tool produces consistent and stable results. In order to elucidate the level of
anxiety, the authors used State-Trait anxiety inventory (Speilberger questionnaire). It is a

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widely used method for the assessment of anxiety symptoms. It consists of 20 different items
of state and anxiety and 20 different items for trait anxiety. Use of same tool for the detection
anxiety further increased the reliability of the selection of the focus group (Spielberger,
Gonzalez-Reigosa, Martinez-Urrutia, Natalicio & Natalicio, 2017).
The authors, Javnbakht, Kenari and Ghasemi (2009) excluded individuals with
previous reported cases of psychiatric disorders, drug abuse and previous experience of yoga.
The authors mainly included T-test and Wilcoxon statistical tests with SPSS 13.0 software in
order to analyze the results and the results are valid and reliable. The analysis of the results
highlighted the prevalence of depression between the test and the placebo groups have no
significant difference. However, the difference was indicated in the level of anxiety. The
mean state of anxiety score before undertaking yoga was 2.29 among the test group. This
state of anxiety was decreased to 1.85 after yoga intervention. The state of anxiety was
highlighted in 41.2% of cases before the conduction of yoga and the percentage got decreased
to 20.6% after the conduction of yoga and this result was statistically significant with a P
value of 0.03 (Javnbakht, Kenari & Ghasemi, 2009).
Internal and External Validity
There are no significant threats in internal validity of the study. According to Kessler
and Vesterlund (2015), internal validity of the study is the extent to which the experiment is
free from errors and any type of difference that is being reflected in the measurement due to
the presence of independent variable. The authors use the common tools in order to measure
the level of anxiety and depression among the selected group of participants both the placebo
and the experimental group. This lead to eradication of threats associated with the internal
validity of the study. However, internal validity also encompasses the alternative explanation
of the results. Javnbakht, Kenari and Ghasemi (2009) though provided the possible reasons

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underlying the decrease in the level of anxiety after yoga but failed to highlight the possible
reasons why the level of depression remained before and after the conduction of yoga.
The external validity of the study is defined as the extent to which the results of the
research can be inferred to the world at large. This is mainly measured in the domain of
establishment of the causal relationships (Kessler & Vesterlund, 2015). This from the above
definition of the external validity, it can be highlighted that there are threats to the external
validity of the study. The reason behind this is, the study’s focus group is the female
population. This restriction of the focus group to the female is the principal threat to the
external validity of the study. The physiological system of men and different from women
and so is the level of stress and depression. Thus, the statistical results in relation of yoga and
the level of anxiety, which is relevant to women, might not be applicable to men. Thus, the
results cannot be inferred to the world at large. Another threat to the external validity of the
research is the Javnbakht, Kenari and Ghasemi (2009) failed to mentioned the yoga postures
or the ashanas which were used during the 2 months long yoga session (twice a week for 90
minutes). This gap is proper explanation and tabulation of the type of yoga ashanas and the
duration of the each ashanas hampered or endangered the external validity of the research.
The reason behind this is, according to Gothe, Pontifex, Hillman, McAuley (2013), different
yoga postures has different effects on different parts of the body thus proper knowledge, and
utility of each posture must be noted in order to get the desired results.
Recommendation to overcome the threats of internal and external validity
The critical analysis of the research highlighted that the study scores less in the
domain of external validity. In order to overcome the potential threats associated with the
external validity of the results the inclusion and the exclusion criteria of the focus group must
be more stringent and defined. The inclusion of the focus group must be designed in such a

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way the it included both the gender, male and female this will help inferred research results to
the world at large. Moreover, the age limit of the groups must be also be defined. For
example, the research conducted by Ibrahim, Kelly, Adams and Glazebrook (2013)
highlighted the young adults or the adults who are either students are working professionals
are the main victims of anxiety and depression. Specific selection focus group (with age
limit) might help to infer the relation of the results at large. Moreover, the stretching exercise
or the yoga postures, which were used in the research during the tenure of 2 months, must
also be elaborated in details. Such that other authors who are planning to replicate the same
results might get an understanding of the effect of postures in reducing the depression or the
level of anxiety. Proper explanation of the postures and its underlying mechanism to reduce
the level of anxiety or anxiety trait will help in the establishment of casual relationships.

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References
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