This was a single-blind RCT comparing stress reduction with the TM program to wait-list controls on change in BP, psychological distress, and coping in young adults. The present study reports on both the overall sample and a subgroup at risk for hypertension. The field site was American University (Washington, DC). The administrative and data-coordinating center was the Center for Natural Medicine and Prevention at Maharishi University of Management Research Institute (Maharishi Vedic City, IA). The institutional review boards of both institutions approved the study. The trial was conducted from January 2006 to May 2007.

The subjects were 298 students from American University and other surrounding colleges, including Georgetown and University of District of Columbia. Inclusion criteria included enrollment in an undergraduate or graduate program through August 2006. Students were excluded if they had a history of hypertension, hypoglycemia, chronic fainting, coronary heart disease, or current BP above 140/90 mm Hg or below 90/60 mm Hg.

Subjects were included in a high-risk subgroup if they had one or more of the following risk factors for hypertension: systolic BP (SBP) >130, diastolic BP (DBP) >85,17 family history of hypertension,18 overweight, or obesity defined as body mass index ≥25.19,20

Interested participants were scheduled for small group informational sessions presented by the research staff and TM instructional staff. After providing written informed consent, students underwent baseline testing.

Students were then randomized to experimental or control groups, using the random blocks method21 stratifying on gender (male/female) and self-reported attention deficit hyperactivity disorder status (yes, no), to either (a) immediate instruction in the TM program or (b) wait list/delayed start condition. (The attention deficit hyperactivity disorder stratification was for the purpose of a separate substudy.)

The treatment group allocations were concealed by the study statistician, with individual treatment group assignments revealed to the project manager only when study participants completed baseline testing. Subjects were post-tested after ~3 months. All assessments were administered by research staff who were masked to treatment condition. Thus, this was a single-blind design. After post-test evaluation, wait-list participants were offered TM instruction.

The primary outcome for the study was casual BP. Secondary outcomes were psychological distress (total mood disturbance, anxiety, depression, anger/hostility) and coping ability (global constructive thinking).

BP was measured in a seated position, with an automated BP monitor (model #UA-787; A&D Medical, Albany, GA) using standard clinical trial technique.22 Three readings were taken in both pre- and post-testing sessions. The first BP reading was taken after an adaptation period of 5 min in which subjects were seated comfortably not practicing any formal relaxation technique. Thereafter, a 1-min adaptation period was used between the first, second, and third readings. The last two were averaged for the study score.

Family history of hypertension was determined by self-report and body mass index by a ratio of weight and height (BMI = weight in kilograms/(height in meters × height in meters)).

Psychological distress was measured with the Profile of Mood States total mood disturbance main scale and tension/anxiety, depression/dejection, and anger/hostility subscales.23 These scales were selected because of the association of these constructs with BP.5 Internal consistency coefficients range from 0.90 to 0.95.23

Coping was measured using the Constructive inking Inventory global constructive thinking main scale, which measures constructive and destructive thinking patterns underlying coping ability.24,25 Previous research has shown that global constructive thinking is sensitive to mind–body intervention.16 The global constructive thinking scale includes emotional and behavioral coping items, with higher scores indicating more positive, healthy coping. Internal consistency is reported to be 0.90.26

The TM technique is the principal mind–body modality of the Maharishi Vedic Approach to Health, a comprehensive traditional system of natural health care derived from the ancient Vedic tradition.27 The TM technique is a simple, natural, and easy-to-learn procedure that allows the ordinary thinking process to become more quiescent and a unique psychophysiologic state of “restful alertness” to be gained.28 This distinctive state of restful alertness,28,29 is characterized by decreased respiration rates, sympathetic tone and hypothalamic–pituitary–adrenal axis activity,30,31 and high electroencephalography coherence.32 The program is practiced twice a day for 20 min while sitting comfortably with eyes closed.33 Students who learned the TM technique were taught by certified instructors, according to the standardized format offered in the United States by Maharishi Vedic Education Development Corporation33 and used in previous trials.34,35

The TM technique was taught in a seven-step course33 as follows: (i) group introductory lecture on potential benefits and previous research (90 min); (ii) group preparatory lecture, discussing the mechanics and origin of the TM technique (90 min); (iii) personal interview (10 min); (iv) personal instruction session (90 min); (v–vii) group “verification and validation of the practice” sessions on 3 consecutive days following personal instruction, verifying correctness of TM practice, and providing the understanding of the mechanics of the TM technique.

After the seven-step course, students were invited to attend individual meetings with the TM instructor to verify the mechanics of practice and maintain regularity. These meetings were held weekly for the first month, then monthly thereafter (30 min each). Weekly (group) knowledge meetings were also available.

Adherence to the TM program was measured via self-report at post-testing among those who had received TM instruction. Participants were asked to describe the regularity of their practice of the TM technique over the preceding week (not at all, less than once/day, once a day, or twice a day). Participants reporting having practiced at least once a day were considered adherent.

Based on previously published data,13 we estimated pre/post-test differences between TM and control groups of −4.4 (s.d. = 8.1) mm Hg for SBP and −3.9 (s.d. = 7.5) mm Hg for DBP. Calculations using SAS Proc Power (SAS, Cary, NC) indicated 90% power to detect significant differences in BP change at the 0.05 level between groups among the whole sample, and 80% power to detect significant differences between groups in the high-risk subsample.

Differences between the treatment groups on demographic and baseline variables was examined using t-tests for continuous variables and χ²-tests for categorical variables, and by multivariate analysis of variance to assess multivariate differences across all variables. To investigate treatment effects on change in outcome variables from baseline and post-test, analysis of covariance (ANCOVA) was performed in the overall sample and in the hypertension risk subgroup on all eligible subjects with baseline and post-test data. In these analyses, the independent variable was TM program vs. the wait-list control condition. Baseline score of the dependent variable was a prespecified covariate; other baseline factors were not used in the primary analyses to statistically adjust estimated treatment effects. Additional ANCOVA were performed covarying also for baseline variables on which there were significant differences between the treatment groups, in order to assess the potential influence of such differences on the treatment outcomes. To investigate relationships in change among the outcome variables, partial correlations controlling for baseline scores for each pair of variables were calculated by multiple regression analysis. All analyses are reported as two-tailed.

Of the 298 participants (average age = 25.5 years), 117 (40%) were men; 62% were Caucasian, 16% African American, 7% Asian American, 4% Hispanic, and 11% were of other ethnicities or declined to report race/ethnicity. Average SBP/DBP was 117/76 mm Hg.

Table 1 shows baseline data for the 207 students who completed both BP baseline and post-testing by group. Multivariate analysis of variance showed no significant differences between groups on baseline variables (F(17,173) = 0.78; P = 0.72).

ANCOVA, covarying for the baseline score of the dependent variable for the 207 subjects who completed baseline and post-test, indicated a mean reduction in SBP for the TM group of −2.0 mm Hg compared to +0.4 mm Hg for wait-list controls (P = 0.15). DBP change was −1.2 mm Hg for the meditation group compared to +0.5 mm Hg for controls (P = 0.15).

The TM group compared to controls showed improvement in total psychological distress (P = 0.004), anxiety (P = 0.003), depression (P = 0.012), and anger/hostility (P = 0.06), sub-scales, and coping ability (P = 0.003) (see Table 2).

Additional BP analysis, covarying for both baseline score of the dependent variable and baseline coping ability indicated a change in SBP for the TM group of −2.0 ± 1.2 mm Hg vs. +0.4 ± 1.1 mm Hg for controls (P = 0.14) and a change in DBP for the TM group of −1.4 ± 0.9 mm Hg vs. +0.6 ± 0.8 mm Hg for controls (P = 0.10).

Reduction in SBP was associated with change in total psychological distress (partial r = 0.19; P = 0.043), anxiety (r = 0.21; P = 0.029), depression (r = 0.21; P = 0.027), and coping ability (r = −0.21; P = 0.026). Reduction in DBP was associated with change in anxiety (partial r = 0.17; P = 0.08) and coping ability (r = −18; P = 0.06).

In addition, change in psychological distress scales and coping ability showed significant negative correlations with each other (partial r values range from −0.44 to −0.68; P values < 0.01).

Of the 93 participants who had received TM instruction and completed post-testing, 64% of the entire sample and 67% of the hypertension risk subgroup reported practicing the TM technique regularly. There was no significant difference between the entire sample and high-risk subgroup with regard to the proportion of TM subjects who were regular in their practice (χ²(1) = 0.365; P = 0.55). An additional 15% in the entire sample and 13% in the subgroup reported some practice of the technique.

Across groups, there were no significant differences between subjects who completed post-testing (n = 207) and those who did not complete post-testing (n = 91) on any of the primary or secondary outcome variables at baseline, either in the whole sample or in the high-risk subgroup. Also no significant differences between the TM group and control group among subjects who did not complete post-testing were observed on any of the primary or secondary outcome variables at baseline, either in the entire sample or in the high-risk subsample.

There were several important methodological strengths, including the use of random assignment, the use of assessors masked to treatment condition to reduce demand characteristics, and a sizable racially diverse subject sample, which lends confidence in the generalizability of the findings to the college student population.

A limitation is that about 30% of the pretest sample was unavailable for post-testing. This concern is mitigated by the fact that across groups completers did not differ from non-completers on any baseline entry characteristics. Also there were no differences between groups on baseline primary and secondary outcomes in noncompleters.

It is unlikely that baseline differences between the treatment arms in the high-risk subsample could have contributed to the observed BP reduction. ANCOVA results for BP were very similar, regardless of whether baseline coping ability, which was significantly different between groups, was included as a covariate. Differences on other baseline variables were relatively small (~0.1 s.d. on BP and 0.2 s.d. on total psychological distress) and are therefore unlikely to have affected the results substantially.

Future randomized trials of the TM program in college students should evaluate longer-term intervention periods to assess long-term effects on BP and psychological distress.

In conclusion, this is the first RCT to demonstrate that a selected mind–body intervention, the TM program, significantly decreased BP in association with improved psychological distress and coping ability in young adults at risk for hypertension. In addition, there were improvements in mental health in the general student sample and trends toward reduction of BP. Practice of this mind–body intervention may be an effective method to reduce psychological distress, BP, and the risk for prospective development of hypertension in high-risk young adults.