Table 1

 Summary of studies

StudyInclusion criteriaExposure*Outcome measure(s)Results from study for primary outcome measure†Comments
Note: values in italics were calculated post hoc as part of this review.
*Values in parentheses are minus dropouts.
†Values reproduced or calculated where data were sufficient, standardised mean differences calculated as per Hedges formula, bias corrected.39
‡Without the assumption of equal variances.40
§Results included at three weeks only
¶Assumed values given were standard deviations rather than standard errors.
**Results included for day of examination only.
††Results for cognitive and somatic anxiety groups combined.
DSM-III-R, Diagnostic and statistical manual of mental disorders, third edition, revised; OCD, Obsessive compulsive disorder; SD, standard deviation; CI, confidence interval.
Key for scales: ACL, anxiety check list; BSASI, Bell’s social adjustment scale; HAS, Hamilton anxiety scale; HDRS, Hamilton’s depression rating scale (HRSD, HAMD); IPAT, Institute for personality and ability testing (anxiety scale); KcIT, Knox-cube imitation test; LoC, locus of control; MMPI, Minnesota multiphasic personality inventory; PIL, purpose in life test; POMS, profile of mood states; PSLES, presumptive stressful life events scale; PSS, perceived stress scale; SCL-90-R OC and GSI, symptoms checklist-90-revised obsessive compulsive and global severity index; SNAQ, snake attitude questionnaire; SSI, symptom sign inventory; STAI, state-trait anxiety inventory; STAS, Spielberger’s test anxiety scale; SUD, subjective unit of disturbance; TAS, Taylor’s anxiety scale; Y-BOCS, Yale-Brown obsessive compulsive scale.
Shannahoff-Khalsa et al22 (n = 22)OCD. DSM-III-R diagnosis plus minimum of 15 on Y-BOCS for the adults.Yoga treatment: kundalini yoga (includes specific OCD technique as well as mantra meditation) (n = 12) (7). Control: relaxation response and mindfulness meditation (n = 10) (7). Both were one hour weekly treatments with instructor plus daily practice. Trial duration: 3 monthsPrimary: Y-BOCS at baseline and after three months. Others: SCL-90-R (OC and GSI), POMS, PSS, and PILSignificant between group mean difference (p = 0.047). Intention to treat analysis: significant reduction in mean for yoga group (p = 0.023) but not for control group (p = 0.058). Mean reduction: yoga group = 9.43 (SD 7.21) (−38.4%); control group = 2.86 (SD 3.13) (−13.9%). Mean difference = 6.57, 95% CI (0.10 to 13.0) p = 0.047 (p = 0.058‡). Standardised mean difference = 1.10, 95% CI (−0.02 to 2.22)Methodology: randomisation: adequate. Allocation concealment: adequate. Blinding of assessors: unknown. Attrition rate: yoga, 41.7% (includes the one adolescent); control, 30%
Sharma et al28§ (n = 71)Anxiety neurosis. Diagnosed with Feighner’s diagnostic criteriaYoga treatment: Yoga (kapalabhati and ujjayi pranayama). One week training then twice daily practice for 10 min each time (n = 41) (33). Control: placebo capsule, once a day (n = 30) (24). Trial duration: 12 weeksPrimary: HAS at three weekly intervals. Others: SUD, various physiological measures and PSLESSignificant between group mean difference (p<0.005) at three weeks indicating greater improvement in yoga group than in control group (p<0.005). Significant improvement for yoga group between 3 and 6 weeks (p<0.01) but not for control group. Mean reduction: yoga group = 6.91 (SD 4.26) (−23.7%); control group = 3.71 (SD 2.18) (percentage change incalculable because of unreliable baseline figure). Mean difference = 3.20 95% CI (1.30 to 5.10) p = 0.001. Standardised mean difference = 0.89, 95% CI (0.34 to 1.44)Methodology: randomisation: non-randomised. Allocation concealment: N/A. Blinding of assessors: unknown. Attrition rate: yoga, 19.5% at 3 weeks, 34.1% at 6 weeks; control, 20% at 3 weeks, 46.7% at 6 weeks; both increasing later. Clinical: anxiety neurosis is not a diagnosis used now. Follow up length seems appropriate
Sahasi et al23 (n = 91)Anxiety neurosis. DSM-III diagnosisYoga treatment: yoga (consisting of sukhasna, talasna, pranayama, nishpand bhav, savasna). Daily practice, 5 days a week instructed, 2 days home practice, 40 min duration (n = 38) (30). Control: diazepam (no dose or frequency given) (n = 53) (18). Trial duration: 3 monthsPrimary: IPAT at baseline and after 3 months. Others: SSI, LoC, and KcITMean changes significant for yoga group (p<0.05) but not for diazepam group (p>0.05). Mean reduction: yoga group = 3.39 (SD 6.81); control group = −0.36 (SD 8.58). Mean difference = 3.75, 95% CI (−0.76 to 8.26) p = 0.101. Standardised mean difference = 0.49, 95% CI (−0.10 to 1.08)Methodology: randomisation: inadequate. Allocation concealment: inadequate. Blinding of assessors: unknown. Attrition rate: yoga, 21.1%; control, 66.0%. Clinical: anxiety neurosis is not a diagnosis used now
Vahia et al24 (n = 27)Psychoneurosis. Diagnosed (method not stated)Yoga treatment: five steps: asana, pranayama, pratyahara, dharana, and dhyana (n = 15). Control: relaxation with postures resembling Asanas and breathing practices resembling Pranayama plus writing (n = 12). Both groups were given placebo tablets. Both practised daily, 1 hour, 6 days a week. Trial duration: 4 weeks minimumPrimary: TAS (weekly, including before and after treatment). Others: Rorschach and MMPISignificant difference between group means after (p<0.001) but not before treatment (p = 0.17). Reduction in mean for yoga group but not control. Concludes significance at 5% level. Mean reduction: yoga group = 6.66 (−26.1%); control group = −0.50 (+1.7%). Mean difference = 7.16Methodology: randomisation: unknown. Allocation concealment: unknown. Blinding of assessors: adequate. Attrition rate: unknown. Clinical: psychoneurosis is no longer used as a diagnosis
Vahia et al29 (n = 39)Psychoneurosis or psychosomatic disorder. Diagnosed (method not stated)Yoga treatment: as Vahia et al28 (n = 21). Control: anxiolytic and antidepressant drugs (amitriptyline and chlordiazepoxide), variable dosage schedule (n = 18). Trial duration: 6 weeksPrimary: TAS (initial (pre), intermediate and final (post) evaluations). Others: HDRS and BSASISignificantly greater pre-post reduction in scores for yoga group than for control group (p<0.05)Methodology: randomisation: non-randomised. Allocation concealment: N/A. Blinding of assessors: adequate. Attrition rate: unknown
Broota and Sanghvi25 (n = 30)Examination anxiety (high score on STAS) plus history of examination anxietyYoga treatment: Broota relaxation technique (exercises adapted from yoga combined with autosuggestion) (n = 10). Control 1: Jacobson’s progressive relaxation technique (n = 10); control 2: talking only (n = 10). All were practised on consecutive days, 20 min duration each. Trial duration: 3 daysPrimary: ACL at baseline (pre) and after 3 days (post). Others: self evaluation ladder scale (anxiety measure)Significant difference between the three groups on the pre-post changes (p<0.01). Mean of the pre-post changes for Broota group significantly greater than Jacobson group (p<0.05) and talking control group (p<0.01)Methodology: randomisation: unknown. Allocation concealment: unknown. Blinding of assessors: not blinded (self assessed). Attrition rate: “many” dropouts for the control group. Clinical: role of author – Broota – in study not clear
Malathi and Damodaran26 (n = 50)¶**Examination anxiety anticipated because of impending examinationYoga treatment: yoga based intervention (various asanas, plus prayer, exercises, visualisation, and meditation) (n = 25) Control: work such as reading and writing (n = 25). Both were practised for 1 hour, 3 times a week Trial duration: 3 monthsPrimary: STAI at pre and post practice, one month before exams and on the day of the examinationSignificant pre-post reduction in mean for yoga group 1 month before examination and on day of examination (p<0.001 for both), no such significant reduction for the control group. Mean reduction on day of examination: yoga group = 15.91 (−34.0%); control group = −1.55 (+3.4%). Mean difference = 17.46Methodology: randomisation: unknown. Allocation concealment: unknown. Blinding of assessors: not blinded (self assessed). Attrition rate: unknown
Norton and Johnson27†† (n = 40)Snake phobia (moderate) identified by SNAQ responsesYoga treatment: slightly modified form of Agni yoga (n = 20). Control: progressive relaxation (n = 20). Phase 1: both were practised for 4 sessions (45 min each) plus home practice. Total duration: 3 weeks. Phase 2: one 15 min practice then one off approach of snake. Variable scheduling dependent on participant’s conveniencePrimary: SNAQ at baseline (before phase 1) and after phase 2. Others: relaxation score (phase 1), approach score, pulse rate, and subjective fear (phase 2)Significant group by treatment interaction on post phase 2 SNAQ (p<0.05). No significant simple main effects on post phase 2 SNAQ. Reduction for yoga group = 4.99(−12.7%); control group = 3.20(−8.6%). Mean difference = 1.79Methodology: randomisation: unknown. Allocation concealment: unknown. Blinding of assessors: not blinded (self assessed). Attrition rate: unknown Clinical: clinical relevance questionable