Introduction
Tension-Type Headache (TH) accounts for approximately 80% of all headache diagnoses (Schwartz, Stewart, Simon and Lipton, Reference Schwartz, Stewart, Simon and Lipton1998). The lifetime prevalence of TH is estimated at 78% for the episodic form (ETH occurring less than 15 days per month) and 6% for chronic form (CTH; occurring more than 15 days per month) (Fumal and Schoenen, Reference Fumal and Schoenen2008). Prevalence of TH has been increasing world-wide since 1989 (Bendtsen and Jensen, Reference Bendtsen and Jensen2006). Tension Type-Headache is associated with significant socio-economic cost through loss of employment productivity, cost to the health care system, and significant reduction in quality of life (Schwartz et al., Reference Schwartz, Stewart, Simon and Lipton1998). Based on these criteria, CTH is in the World Health Organization's top 10 ranking of illness by disability (Fumal and Schoenen, Reference Fumal and Schoenen2008).
Despite the impact of CTH, the majority of sufferers do not seek treatment. Rather, most CTH sufferers self-medicate with over the counter (OTC) analgesic such as paracetamol and codeine (Fumal and Schoenen, Reference Fumal and Schoenen2008). In ETH this treatment is usually sufficient; however, in CTH nearly half of all sufferers report that their pain is not under control (Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). This results in vulnerability to chronic analgesic use, which is associated with dependence, tolerance, and decreased effectiveness over time (Hutchinson et al., Reference Hutchinson, Bland, Johnson, Rice, Maier and Watkins2007). Further, up to 20% of CTH suffers who use analgesics chronically develop so-called Medication Overuse Headache (MOH), which involves increased headache severity and associated psycho-social impairment (Schoenen, Reference Schoenen, MacMahon and Koltzenburg2006). The self-treatment of CTH with OTC analgesics is therefore problematic, and highlights the need for improved treatment strategies. The long-term efficacy of behavioural intervention for CTH may equal pharmacological treatment (Fumal and Schoenen, Reference Fumal and Schoenen2008). Further, behavioural intervention is not associated with side effects of drug therapy, addresses psycho-social factors associated with CTH, and teaches self-management skills. The most common behavioural intervention for CTH is cognitive behavioural therapy (CBT), which has significant evidence supporting its efficacy (Fumal and Schoenen, Reference Fumal and Schoenen2008; Martin and MacLeod, Reference Martin and MacLeod2009; Schoenen Reference Schoenen, MacMahon and Koltzenburg2006).
Mindfulness Based Therapy (MBT) is another possible treatment option for chronic pain that is receiving increased attention in the literature. Mindfulness involves paying attention to one's moment-to-moment perceptions, cognitions, emotions or sensations, in a non-judgemental, accepting, and non-reactive way (Kabat-Zinn, Lipworth, Burney and Sellers, 1Reference Kabat-Zinn, Lipworth, Burney and Sellers986; Morone, Greco and Weiner, Reference Morone, Greco and Weiner2008; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). Typically, MBT for chronic pain is based on the 8-session Mindfulness Based Stress Reduction (MBSR) program developed by Kabat-Zinn and colleagues (Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth and Burney1985). Such programs have been found successful for decreasing symptoms in back pain (Morone et al., Reference Morone, Greco and Weiner2008), fibromyalgia (Singh, Berman, Hadhazy and Creamer, Reference Singh, Berman, Hadhazy and Creamer1998), arthritis (Pradhan et al., Reference Pradhan, Baumgarten, Langenberg, Handwerger, Gilpin and Magyari2007), musculoskeletal pain (Plews-Ogan, Owens, Goodman, Wolfe and Schorling, Reference Plews-Ogan, Owens, Goodman, Wolfe and Schorling2005), and groups of heterogeneous chronic pain sufferers (Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth, Burney and Sellers1986).
Experimental evaluation of MBT specifically for CTH has not to date been reported in the literature. However, a recent uncontrolled study reported a decrease in headache in a sub-set of N = 15 combined “headache/migraine” sufferers receiving mindfulness training as part of a mixed-diagnosis pain group (Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). In contrast, Rosdahl (Reference Rosdahl2003) and Nash-McFeron (Reference Nash-McFeron2006) both reported non-significant reductions in headache intensity following MBSR training in samples of mixed headache diagnoses (ETH, CTH, migraine). The potential of MBT for headache, and CTH particularly, therefore remains unclear at present.
An as yet under-explored issue in the use of mindfulness interventions for chronic pain is the length of the intervention required to achieve clinical efficacy. Standard MBSR programs traditionally involve 26 hours of session time involving eight 2½-hour sessions and a day-long class. The time and cost commitment from patients to undertake the standard program has been widely noted as a key limitation to MBT for chronic pain (Carmody and Baer, Reference Carmody and Baer2009; Kingston, Chadwick, Meron and Skinner, Reference Kingston, Chadwick, Meron and Skinner2007; Zeidan, Gordon, Merchant and Goolkasian, Reference Zeidan, Gordon, Merchant and Goolkasian2010).
To date, every published trial of mindfulness for chronic pain has involved a minimum of eight sessions, comprising at least 12 in-class hours (see Carmody and Baer, Reference Carmody and Baer2009 for a review). However, a recent review found that treatment outcome was not correlated with program duration or number of sessions, suggesting research exploring brief versions of MBT is warranted (Carmody and Baer, Reference Carmody and Baer2009). Consistent with this, a few recent studies have shown that brief mindfulness meditation training (courses ranging from 3 sessions in 3 days to 6 sessions in 3 weeks) have been effective at reducing acute pain sensitivity in healthy subjects (Kingston et al., Reference Kingston, Chadwick, Meron and Skinner2007; Zeidan et al., Reference Zeidan, Gordon, Merchant and Goolkasian2010). Similarly, a controlled study reported four 1½-hour sessions of mindfulness meditation reduced stress and increased positive mood states in university students self-identified as experiencing stress (Jain et al., Reference Jain, Shapiro, Swanick, Roesch, Mills and Bell2007).
Since CTH is associated with increased pain sensitivity, stress, and negative mood (Bezov, Ashina, Jensen and Bendtsen, Reference Bezov, Ashina, Jensen and Bendtsen2011; Nash and Thebarge, Reference Nash and Thebarge2006), and since MBT has been effective in reducing pain sensitivity, stress, and negative mood (e.g. see Carmody and Baer, Reference Carmody and Baer2009 for a review; Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth and Burney1985; Morone et al., Reference Morone, Greco and Weiner2008; Plews-Ogan et al., Reference Plews-Ogan, Owens, Goodman, Wolfe and Schorling2005; Zeidan et al., Reference Zeidan, Gordon, Merchant and Goolkasian2010), such interventions may be effective in CTH. No studies to date, however, have examined brief MBT for CTH, or any headache diagnosis. Indeed, no studies to date have examined the use of MBT of any duration for CTH exclusively. Evaluating such programs is of significant importance to the continued development of mindfulness-based treatment for chronic pain, and chronic headache in particular. The present study therefore conducted a randomized controlled trial of a brief mindfulness-based intervention specifically designed for treating CTH.
Method
Participants
Participants were recruited from the general population via advertisements in local print, radio and television media requesting volunteers for a study on headaches. Written consent from each subject for study participation was obtained and the study was approved by the University's Human Research Ethics Committee. Potential volunteers underwent a screening interview conducted by the senior author and based on the International Classification of Headache Disorders (International Headache Society, 2004). Inclusion criteria were: satisfying ICHD-II criteria for Chronic Tension-Type Headache, aged 18–65 years, not currently receiving (or having received in the last 12 months) intervention for headache, no psychiatric or major medical condition currently or in the last 12 months, no other headache or pain symptoms or diagnoses in addition to CTH, including suspected or probable Medication Overuse Headache (i.e. medication use 10 or more days per month, for 3 or more months). Of 94 volunteers, 58 met inclusion criteria and were admitted to the study. Six participants withdrew from the Treatment group and 10 participants withdrew from the wait-list Control group, resulting in a total completion sample of 42 (see Figure 1).
Figure 1. CONSORT flow diagram
Procedures
Participants were randomly allocated to either the treatment or wait-list control condition by an off-site third party who had no contact with participants. The researchers that administered and assessed the outcome measures were all blind to group. Self-report questionnaires and headache diaries were completed by the treatment and wait-list control groups before and immediately after the treatment group completion of the MBT course. There was no further follow-up assessment. The wait-list control group completed the MBT course following completion of the second assessment battery by all participants. Post intervention assessments were not conducted for the wait-list control group.
Measures
Socio-demographic and clinical questionnaire
Participants completed an in-house questionnaire assessing socio-demographic and clinical details (see Cathcart and Pritchard, Reference Cathcart and Pritchard2008).
Five Facet Mindfulness Questionnaire
The Five Facet Mindfulness Questionnaire (FFMQ; Baer, Smith, Hopkins, Krietemeyer and Toney, Reference Baer, Smith, Hopkins, Krietemeyer and Toney2006) is a 39-item self-report measure of mindfulness that consists of five subscales: observing, describing, acting with awareness, non-judging of inner experience, and non-reactivity to inner experience. Items are rated on a 5-point Likert-type scale ranging from 1 (never or very rarely true) to 5 (very often or always true). Adequate internal reliability, construct validity and incremental validity have been reported elsewhere (Baer et al., Reference Baer, Smith, Hopkins, Krietemeyer and Toney2006).
Headache diary
Participants recorded headache activity for a 2-week period in a clinical diary detailed elsewhere (Cathcart and Pritchard, Reference Cathcart and Pritchard1998). The mean headache intensity, frequency and duration over the 2-week period were calculated as dependent variables.
Depression Anxiety Stress Scales - 21
The Depression Anxiety Stress Scales - 21 (DASS21; Lovibond and Lovibond, Reference Lovibond and Lovibond1995) is a 21-item self-report questionnaire containing subscales for measuring depression, anxiety and stress, which participants respond to using a 4-point Likert-type scale. Scores are calculated for each sub-scale by summing the relevant items and then multiplying by two. The DASS-21 has high internal consistency, and moderately high construct and convergent validity (Lovibond and Lovibond, Reference Lovibond and Lovibond1995).
Intervention
The MBT intervention, based on MBSR (Kabat-Zinn, Reference Kabat-Zinn1982) and Mindfulness Based Cognitive Therapy (MBCT; Segal, Williams and Teasdale, Reference Segal, Williams and Teasdale2002) was conducted over a 3-week period involving twice-weekly group classes and daily practice (see Appendix A for an outline of the course). The program, which included a particular focus on management of headache pain and related psycho-social sequelae, and management of stress as a contributing factor to headache, was developed by some of the authors (SC, MP, MI) who are psychologists (SC, MP) with formal training in mindfulness therapy (e.g. completion of MBSR and MBCT training courses, and clinical experience in the delivery of these), and extensive teaching, practice and research experience in mindfulness-based meditation (e.g. university lecturing and research, and clinical practice instruction) (MP, SC, MI).
Three formal mindfulness meditation practices were taught during the MBT sessions: 1) body scan meditation, which involves focusing on and feeling each region of the body systemically from the foot to the head, and noticing the sensations that are present with openness and curiosity; 2) formal sitting meditation, focusing on mindfulness of breath and other experiences such as sounds and thoughts; 3) 3-minute breathing space, which involves three sequential steps: a) focusing awareness of present internal experiences; b) focusing awareness on the breath; and c) expanding awareness to the body as a whole. Discussions in class assisted participants in applying principles of mindfulness to the meditation and beyond to daily activities and interactions, in order to establish mastery on awareness of responses to stressful situations or challenges and associated emotional, behavioural and physiological responses. The program also included other activities so that participants could practise applying concepts of mindfulness to activities of daily living, recognizing activities that are nourishing and draining and documenting observations and reactions to pleasant and unpleasant events (see Appendix A).
The 2-hour group classes were delivered on a suburban campus of the University of South Australia and were facilitated by an author (MI). Daily mindfulness meditation home practice, lasting about 30 minutes each day, was supported by a written instruction manual and a compact disc containing audio-recorded meditation practice instructions. Thirty minutes was chosen as long enough to complete the meditations while keeping time demands as short as possible for participants. Additional activities involving applications of mindfulness were based on instructions provided in the written manual. Participants maintained a record of when they had completed mindfulness meditation and related activities at home using handouts that were provided after each session and which were submitted at the beginning of the subsequent group session.
Data analyses
Statistical analyses were conducted using the Statistical Package for the Social Sciences (SPSS Version 17, Vesta Services Inc, 2009). Groups were compared on socio-demographic and baseline data using t-tests for parametric data and chi-square for categorical data. Repeated Measures Analysis of Variance (RMANOVA) was used to examine changes in mindfulness and psychological measures following mindfulness training compared with wait-list control. Headache data were modelled using Generalized Estimating Equations (GEE). Like Mixed Models, GEE is model dependency, obtaining the population-averaged trend rather than estimating individual regression coefficients. The method is robust to misspecification of the correlation structure (Liang and Zeger, Reference Liang and Zeger1986), which was evident in the headache data. Statistical significance was set at alpha = .05.
Results
Participant characteristics and baseline data
Participant characteristics and clinical data for treatment and wait-list control groups are presented in Table 1. There were no significant differences between groups on measures of age (t = .12, p = .90), gender (Chi = .63, p = .43) or headache activity (all t-tests p >.05). There were no significant differences between groups on depression (t = 1.75, p = .09) and stress (t = .99, p = .33) subscales of the DASS-21, while the wait-list control group had significantly higher anxiety ratings than treatment group (t = 2.08, p = .04). All DASS-21 subscale scores were within the normal to mild range for treatment and control groups. Due to the group differences in anxiety at baseline, this initial score was evaluated as a covariate in modelling treatment effects on headache activity and mindfulness. However, anxiety was not significant as a covariate in any of these models (all p>.05). Of the six intervention sessions, participants attended a Mean of 5.1 sessions (SD = 0.64).
Table 1. Participant characteristics and baseline clinical data for treatment and wait-list control groups
Notes: ^ Chi-square test
aHeadache diary; b Depression Anxiety Stress Scales 21; *Significant at the 0.05 level (2-tailed). All test df = 40 except for ^ df = 1.
Treatment effects on headache activity
Table 2 shows the pre- and posttreatment means for headache frequency over the 2-week diary period for treatment and control group participants. Mean scores for pretreatment headache frequency for treatment and control groups were 11.04 days (SD = 3.45) and 9.82 days (SD = 3.34) respectively. Posttreatment headache frequency was 9.37 days (SD = 4.79) for the treatment group, and 9.65 days (SD = 3.24) for the control group. The Generalized Estimated Equation indicated a significant time effect (Chi = 6.16, df = 1, p = .01, partial η2 = .56), and a significant group by time interaction (Chi = 4.32, df = 1, p = .04, partial η2 = .42), while group effects were not significant (Chi = .50, df = 1, p = .60). Sequential Bonferroni adjusted post-hoc comparisons confirmed the time effect was due to a reduction in headache frequency in the treatment group (Mean Difference = -1.67, df 1, p = .016). Number of sessions attended did not correlate with posttreatment headache or mindfulness (r .-04, -.16, all p>.05).
Table 2. Headache scores in treatment and control groups
Notes: aTreatment group n = 22, control group n = 19; b Generalized Estimating Equation Chi Square value for time effects. All tests df = 1; c Time effects p value; d Generalized Estimating Equation Chi Square value for group x time effects; e Group x time effects p value.
Table 2 shows the pre- and posttreatment means for headache duration (hours) for treatment and control group participants. Mean scores for pretreatment headache duration for treatment and control groups were 7.99 hours (SD = 5.35) and 7.65 hours (SD = 5.05) respectively. Posttreatment headache duration was 7.73 hours (SD = 5.44) for the treatment group, and 7.07 hours (SD = 3.99) for the control group. The Generalized Estimated Equation indicated group (Chi = .04, df = 1, p = .84), time (Chi = .14, df = 1, p = .71) and group by time (Chi = .00, df = 1, p = .99) effects were not significant.
Table 2 shows the pre- and posttreatment means for headache intensity for treatment and control group participants. Mean scores for pretreatment headache intensity for treatment and control groups were 2.26 (SD = .62) and 2.51 (SD = .82) respectively. Posttreatment headache intensity was 2.16 (SD = .83) for the treatment group, and 2.23 (SD = .79) for the control group. The Generalized Estimated Equation indicated group (Chi = .30, df = 1, p = .58), time (Chi = 1.74, df = 1, p = .19) and group by time (Chi = .03, df = 1, p = .86) effects on headache intensity were not significant.
Treatment effects on psychological measures
Table 3 shows the means and standard deviations of the treatment and control groups for pre- and posttreatment scores for total FFMQ scores and the five facets of the FFMQ. Group, time, and group by time effects were non-significant for all FFMQ scores except Observe, for which there was a significant group by time effect (F(1,39) = 6.80, p = .01, partial η2 = .31). Post hoc paired t-tests indicated that there was a significant increase in Observe from baseline to posttreatment in the treatment group (t = 2.27, df = 21, p = .03), while Observe did not significantly change from baseline to posttreatment in the control group (t = 1.42, df = 21, p = .17). There were no significant time or group by time effects for any DASS items (all p.05).
Table 3. Mindfulness scores in treatment and control groups
Notes: aTreatment group n = 22, Control group n = 19; bRepeated measures analysis of variance, F-value for time effects. All tests df = 39; cTime effects p value; dRepeated measures analysis of variance, F-value for group x time effects; eGroup x time effects p value.
Discussion
Effects of brief mindfulness-based therapy on headache and mindfulness
The present pilot study is the first randomized controlled trial of a mindfulness-based intervention exclusively for CTH. Results, while requiring further investigation, indicated a statistically significant reduction in headache frequency in the treatment but not control group. This is consistent with previous studies where mindfulness meditation has been helpful for chronic pain, including headache (Kabat-Zinn, Reference Kabat-Zinn1982, Kabat-Zinn, Lipworth and Burney, Reference Kabat-Zinn, Lipworth and Burney1985; Nash-McFeron, Reference Nash-McFeron2006; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). Previous studies of mindfulness for chronic pain, however, have typically not been randomized controlled trials (e.g. Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010), or have not examined the use of mindfulness in CTH sufferers exclusively.
A major limitation to standard mindfulness interventions for chronic pain is the program duration and contact hours required, which has been noted as prohibitive for many patients (Kingston et al., Reference Kingston, Chadwick, Meron and Skinner2007). In a recent meta-analysis, Carmody and Baer (Reference Carmody and Baer2009) found that shortened versions of MBSR were comparable to standard MBSR in reducing psychological distress. Further, preliminary research indicates brief MBT may reduce stress and pain sensitivity (e.g. Zeidan et al., Reference Zeidan, Gordon, Merchant and Goolkasian2010), both of which are associated with CTH (Bezov et al., Reference Bezov, Ashina, Jensen and Bendtsen2011; Cathcart, Petkov, Winefield, Lushington and Rolan, Reference Cathcart, Petkov, Winefield, Lushington and Rolan2010; Nash and Thebarge, Reference Nash and Thebarge2006). Hence, the present study examined the efficacy of a brief MBT, consisting of six 2-hour sessions, conducted over 3 weeks. The results suggest that shortened versions of standard MBSR may be beneficial for reducing the frequency of headache episodes in CTH sufferers. The reduced patient demands associated with brief MBT may increase the suitability of this treatment option for many patients.
It is unclear why treatment effects were observed only for headache frequency but not intensity or duration. Rosdahl (Reference Rosdahl2003) also found no effect of mindfulness meditation on headache duration or intensity in a mixed sample of ETH, CTH and migraine sufferers. Tension-type headache has been found difficult to treat due to complex pathophysiology and psychosocial factors (Fumal and Schoenen, Reference Fumal and Schoenen2008), and previous behavioural treatment studies with heterogeneous headache samples found TH sufferers did not improve as much as migraine sufferers. (Fitchel and Larsson, Reference Fitchel and Larsson2001; Sartory, Muller, Metsch, and Pothmann, Reference Sartory, Muller, Metsch and Pothmann1998; Blanchard, Kim, Hermann, and Steffek, Reference Blanchard, Kim, Hermann and Steffek1993). Potentially, previous intervention studies may have only been effective for one headache type (e.g. migraine), since results were not separated for headache type (e.g. Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth and Burney1985; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). Alternatively, the brief intervention used in the present study (six sessions over 3 weeks) may not provide sufficient instruction and/or enough participant practice to reduce headache intensity or duration. Indeed, Nash-McFeron (Reference Nash-McFeron2006) found that it was not until the seventh week of an 8-week MBSR program that participants had significant decreases in headache pain. A limitation in many previous trials of mindfulness for chronic pain is the failure to include measures of mindfulness (e.g. Morone et al., Reference Morone, Greco and Weiner2008; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). Using the FFMQ, the present study found an increase in the mindfulness facet of Observe in the treatment but not the wait-list control group. This is consistent with previous studies reporting that MBT can increase mindfulness and decrease pain in chronic pain (Pradhan et al., Reference Pradhan, Baumgarten, Langenberg, Handwerger, Gilpin and Magyari2007; Schmidt et al., Reference Schmidt, Grossman, Schwarzer, Jena, Naumann and Walach2011) and healthy (Kingston et al., Reference Kingston, Chadwick, Meron and Skinner2007; Zeidan et al., Reference Zeidan, Gordon, Merchant and Goolkasian2010) samples. These studies, however, found an increase in overall mindfulness, whereas the present study did not. It is unclear whether differences in the mindfulness measures used across studies may contribute to this. For example, Zeidan et al. (Reference Zeidan, Gordon, Merchant and Goolkasian2010) and Schmidt et al. (Reference Schmidt, Grossman, Schwarzer, Jena, Naumann and Walach2011) both used the Freiburg Mindfulness Inventory, and Kingston et al. (Reference Kingston, Chadwick, Meron and Skinner2007) used the Kentucky Inventory of Mindfulness Skills. The FFMQ used in the present study is a measure of mindfulness disposition (Baer et al., Reference Baer, Smith, Hopkins, Krietemeyer and Toney2006), which may reflect more “trait” than “state” levels of mindfulness, and hence may have required a longer period of intervention or measurement latency for optimal change.
We found no change in stress, depression, or anxiety in either the treatment or wait-list control groups. Previous mindfulness interventions have been successful in reducing stress, anxiety, and depression (Zautra et al., Reference Zautra, Davis, Reich, Nicassio, Tennen and Finan2008; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010; Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth, Burney and Sellers1986), and anxiety, stress, and depression have all been related to CTH activity (Nash and Thebarge, Reference Nash and Thebarge2006). However, while stress, anxiety and depression are related to headache activity, they are not increased in CTH compared to non-headache sufferers in all studies (e.g. Blanchard et al., Reference Blanchard, Kim, Hermann and Steffek1993; see Cathcart, Winefield, Lushington and Rolan, Reference Cathcart, Petkov, Winefield, Lushington and Rolan2010; Cathcart, Petkov et al., Reference Cathcart, Winefield, Lushington and Rolan2010). Further, the present study excluded participants with diagnosed depression or anxiety. The lack of reduction in stress, anxiety and depression scores in the present study may therefore be due to a restriction in range on these measures.
While we did not assess possible mediating roles of anxiety, stress or depression, it is unlikely that the reduction in headache frequency was due to a reduction in anxiety, stress or depression levels in CTH sufferers. That is, if the reduction in headache frequency was due to a reduction in stress, anxiety or depression, then a reduction in these measures would be expected. Indeed, anxiety was not significant as a covariate in the treatment effect modelling.
Limitations
A major limitation to this study was the small sample size, and we did not conduct an a priori power analysis. However, the sample size was considered adequate for the present pilot study, as no previous studies have examined brief MBT in chronic pain populations, including CTH sufferers. Further, we found statistically significant results demonstrating that the sample size was adequate to detect some changes due to treatment. Future research with a larger sample size appears warranted.
As the present study was a pilot trial of a novel MBT, the validity and reliability of the intervention are unclear. However, the protocol was developed by psychologists with formal training in MBSR, was based closely on the standard MBSR and MBCT protocols and recent brief versions of same (e.g. Jain et al., Reference Jain, Shapiro, Swanick, Roesch, Mills and Bell2007), was documented in a detailed manual, and was delivered by an expert and experienced mindfulness-based meditation practitioner. We did not include an active control condition, hence we cannot exclude the possibility that the effects in the treatment group were due to non-specific factors. Further research could examine the reliability and validity of the present brief MBT protocol.
The relatively high drop-out rate in the present study is of concern. It may be that those participants completing the study differed from those who did not, hence our “completers” may not be representative of the population of interest. However, to partially explore this post-hoc, we conducted t-tests on baseline headache, stress, anxiety, depression, and FFMQ data, and found no differences between completers and non-completers (all p > .05). Similarly, due to the high drop-out rate, future research may benefit from conducting intention-to-treat analyses rather than only analysing complete repeated measures data as in the present study.
Since there are no reports to date of mindfulness-based interventions exclusively in CTH sufferers, we cannot make any conclusions on the efficacy of the present brief MBT compared to standard length (e.g. 8-week) mindfulness-based interventions for chronic pain. Further research comparing these protocols is needed.
Although we excluded probable medication overuse headache from the sample, we did not measure medication use during the trial. Potentially, medication use before and during the trial may have affected outcomes, and this should also be explored in future research.
Finally, only 28% of participants returned all of the home practice record sheets. Hence, we were unable to analyse these data. Potentially, such data may have informed why there was little improvement in headache intensity and duration as well as mindfulness. It has been shown that time spent engaging in home mindfulness meditation practice is related to the extent of improvement in mindfulness and well-being (Carmody and Baer, Reference Carmody and Baer2008), and regular meditation practice over time has better physiological and psychological outcomes (Kabat-Zinn et al., Reference Kabat-Zinn, Lipworth, Burney and Sellers1986; Rosenzweig et al., Reference Rosenzweig, Greeson, Reibel, Green, Jasser and Beasley2010). However, as noted by others (Baer et al., Reference Baer, Smith, Hopkins, Krietemeyer and Toney2006; Grossman, Neimann, Stefan and Walach, Reference Grossman, Neimann, Stefan and Walach2004), even when such data are obtained, it is unknown whether a person is truly performing mindfulness meditation, and participants may exaggerate the amount of practice they did for social desirability.
Conclusion
Although requiring further research, the results of the present study suggest brief mindfulness-based interventions may be effective for reducing headache activity in CTH sufferers. Development of brief mindfulness-based interventions may offer improved treatment options for CTH.
Acknowledgements
The authors thank Margaret Mitchell for assistance in data collection and analysis.
Appendix: Outline of the six-session mindfulness-based therapy course conducted over 3 weeks
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