Adopting and maintaining physical activity behaviours in people with

0 downloads 0 Views 228KB Size Report
Sep 16, 2015 - Objective. Physical activity can improve the health of people with serious mental illness (SMI) but many are inactive. Adopting ...
Preventive Medicine 81 (2015) 216–220

Contents lists available at ScienceDirect

Preventive Medicine journal homepage: www.elsevier.com/locate/ypmed

Adopting and maintaining physical activity behaviours in people with severe mental illness: The importance of autonomous motivation Davy Vancampfort a,b,⁎, Brendon Stubbs c,d, Sumanth Kumar Venigalla e, Michel Probst a,b a

UPC KU Leuven, Campus Kortenberg, University of Leuven, Department of Neurosciences, Kortenberg, Belgium University of Leuven, Department of Rehabilitation Sciences, Leuven, Belgium Physiotherapy Department, South London and Maudsley NHS Foundation Trust, Denmark Hill, London SE5 8AZ, United Kingdom d Health Service and Population Research Department, Institute of Psychiatry, King's College London, De Crespigny Park, London Box SE5 8AF, United Kingdom e Institute of Mental Health, Singapore, Singapore b c

a r t i c l e

i n f o

Available online 16 September 2015 Keywords: Physical activity Exercise Motivation Schizophrenia Depression Bipolar disorder

a b s t r a c t Objective. Physical activity can improve the health of people with serious mental illness (SMI) but many are inactive. Adopting theoretically-based research considering the motivational processes linked to the adoption and maintenance of an active lifestyle between different diagnostic groups of people with SMI can assist in understanding physical activity in this group. Within the Self-Determination Theory (SDT) and the TransTheoretical Model (TTM) (stages of change) frameworks, we investigated differences in motives for physical activity between different diagnostic groups. Methods. All participants completed the Behavioral Regulation in Exercise Questionnaire 2 (BREQ-2), the International Physical Activity Questionnaire (IPAQ) and the Patient-centered Assessment and Counseling for Exercise (PACE) questionnaire. Results. Overall 294 persons with SMI (190♀) (43.6 ± 13.6 years) agreed to participate. People with affective disorders had higher levels of introjected regulations than people with schizophrenia. No significant differences were found for other motivational regulations. Moreover, no significant differences were found according to gender, setting and educational level. Multivariate analyses showed significantly higher levels of amotivation and external regulations and lower levels of identified and intrinsic regulations in the earlier stages of change. Strongest correlations with the IPAQ were found for motivational regulations towards walking. Conclusions. Our results suggest that in all people with SMI the level of identified and intrinsic motivation may play an important role in the adoption and maintenance of health promoting behaviours. The study provides a platform for future research to investigate the relationships between autonomy support, motivational regulations and physical and mental health variables within lifestyle interventions for this population. © 2015 Elsevier Inc. All rights reserved.

Introduction People with severe mental illness (SMI) experience a marked premature mortality which is largely attributed to natural causes and in particular cardiovascular disease (Walker et al., 2015). Physical activity is broadly as effective as pharmacological interventions to treat cardiovascular disease in the general population (Naci and Ioannidis, 2013). A recent systematic review established that physical activity improves the physical and mental health and health related quality of life of people with severe mental illness (SMI) (Rosenbaum et al., 2014). Despite this promising evidence, only a minority of individuals with SMI engage

⁎ Corresponding author at: UPC KU Leuven, Campus Kortenberg, KU Leuven, University of Leuven, Department of Neurosciences, Leuvensesteenweg 517, 3070 Kortenberg, Belgium. Fax: +32 2 759 9879. E-mail address: [email protected] (D. Vancampfort).

http://dx.doi.org/10.1016/j.ypmed.2015.09.006 0091-7435/© 2015 Elsevier Inc. All rights reserved.

in physical activity and exercise at a level compatible with public health recommendations (Soundy et al., 2014a). One explanation for this is that many people with SMI lack sufficient motivation to adopt and maintain an active lifestyle (Soundy et al., 2014a). This lack of motivation can be explained by several factors. First, the presence of psychiatric symptoms may result in people with SMI being disinterested or not valuing the beneficial health outcomes enough to make physical activity a priority (Vancampfort et al., 2015a). Second, people with SMI may not feel sufficiently competent to transform their intention into action and maintained engagement (Kramer et al., 2014), or are suffering from somatic co-morbidities that present a real or perceived barrier (Stubbs et al., 2014, 2015; Vancampfort et al., 2013a). Nevertheless, a better understanding of the motivational deficits in people with SMI, may hold the key to increasing physical activity in this group. Thus, there is a need for theoretically based research investigating the motivational processes linked to the adoption and maintenance of physical activity in people with SMI (Vancampfort and Faulkner, 2014).

D. Vancampfort et al. / Preventive Medicine 81 (2015) 216–220

One approach to address this is by utilising the Self-Determination Theory (SDT) (Deci and Ryan, 2000). The SDT examines the differential effects of qualitatively different types of motivation that can underlie physical activity behaviour (Deci and Ryan, 2000). SDT describes motivation as being multidimensional and residing along a continuum of increasing self-determination (also called autonomous motivation). At the lowest end of the continuum is amotivation, in which case individuals lack the motivation to adopt an active lifestyle. External regulation refers to commencing and continuing physical activity to avoid punishment or other-disappointment or to obtain promised rewards or otherappreciation. Next, introjected regulation refers to the imposition of pressures by feelings of guilt or self-criticism while identified regulations indicate that for the person the physical activity outcomes are personally important (for example mental health improvements or prevent somatic co-morbidities). Finally, intrinsic motivation represents the most autonomous type of motivation and involves being physically active for its own sake, because one finds it challenging or enjoyable. Recent research has considered the SDT in people with schizophrenia (Vancampfort et al., 2013b, 2014) and among people with affective disorders (Vancampfort et al., 2015b) establishing that higher autonomous motivation is significantly related to greater participation in physical activities. However, data comparing these different diagnostic groups with each other is currently lacking. If any difference in motivation towards adopting and maintaining an active lifestyle in a subgroup is observed, this could potentially help guide health care professionals in their treatment decisions. In addition, comparing data across and between major diagnostic categories allows for investigation of the effect of demographic variables (age, gender, body mass index, diagnosis, settings, educational level) on a larger scale. Moreover, since many mental health services include people with each diagnostic group in one setting, the results will have wider implications and reflect typical mental health services. In light of the complex and dynamic nature of physical activity behaviour in people with SMI, it also is essential to assess a person's physical activity patterns over a longer term. Although a longitudinal design would be ideal to answer this question, an individual's intentions to maintain engagement in physical activity can be indirectly captured through the assessment of the stages of change of the transtheoretical model (TTM) (Prochaska and Di Clemente, 1983; Prochaska and Marcus, 1994). The TTM provides a framework for categorising a person's readiness to change their behaviour and includes five stages. In the pre-contemplation phase, individuals are physically inactive and are not thinking about becoming more active within the next six months while in the contemplation stage they think about becoming more active within the next six months. In the preparation stage individuals are engaging in some physical activity, while in the penultimate action stage individuals have been regularly active for less than six months. Lastly, the maintenance stage is characterised by an individual having sustained regular physical activity for more than six months. Given the aforementioned, the current study has four major aims: (1) to establish if motivation towards physical activity differs between diagnostic subgroups (schizophrenia versus major depressive disorder versus bipolar disorder); (2) to explore whether differences in motivation towards physical activity exist according to gender (male versus female), educational status (low versus high education), and setting (inpatients versus outpatients) in a large sample of persons with SMI; (3) to evaluate differences in motivation towards physical activity across the stages of change; (4) investigate if current physical activity levels of people with SMI are related to different motivation types. Methods Participants and procedure The procedure of this multi-centre cross-sectional study has been described elsewhere more in detail (Vancampfort et al., 2014, 2015b). Fifteen (see

217

Acknowledgments section) of 16 invited psychiatric centres agreed to participate. One centre did not participate due to organizational reasons (lack of time). Data were collected in 2 waves. Over a 4-month period in- and outpatients with a DSM-IV diagnosis of schizophrenia were invited to participate (first wave). In the second wave, a 6-month period, in- and outpatients with a DSM-IV diagnosis of either major depressive disorder or bipolar disorder (American Psychiatric Association, 2000) were invited to participate. The diagnosis for all included participants was established by experienced psychiatrists responsible for the patients' treatment and who were not involved in the study. Only patients with a clinical global impression severity scale (Guy, 1976) score of 3 or less assessed by a trained psychiatrist during a semi-structured interview, and who were able to concentrate for 20 to 25 min were included. No incentive was provided for participation. The study procedure was approved by the 15 local ethical committees and all participants provided written informed consent.

Demographic variables Demographic variables assessed included gender, age and body mass index (BMI). Next to this, dichotomous variables were constructed for education (lower: non, vocational or technical training, general education; higher: college or university) and treatment setting (in- versus out-patients).

Behavioral Regulation in Exercise Questionnaire 2 (BREQ-2) The Dutch version of the BREQ-2 (Markland and Tobin, 2004) was used. The BREQ-2 considers an individual's motivation towards exercise. We adapted the BREQ-2 by replacing the term “exercise” with the term “physical activity”. The BREQ-2 comprises 19 items relating to five motivation types from the SDT. Each item is measured on a five-point Likert-scale, from 0 (‘Not true for me’) to 4 (‘Very true to me’). The mean of the 5 retrieved subscales is calculated on a five-point scale to score the extent of each motivation type separately.

The International Physical Activity Questionnaire (IPAQ)-short version The IPAQ-short version (Craig et al., 2003) was used. The IPAQ utilises a 7day recall period. Data from the IPAQ is summarized according to total minutes of walking, moderate and vigorous physical activity per week.

Stage of readiness to change: Patient-centered Assessment and Counseling for Exercise (PACE) questionnaire Stages of change were assessed using a modified version of the stage of change questionnaire from the PACE questionnaire (Long et al., 1996). For this study, physical activity was defined as moderate intensity activity for 30 min on most days of the week (e.g., activities that take moderate physical effort and make you breathe somewhat harder than normal). Participants chose one of five options: “I'm not physically active and I don't intend to start” (precontemplation); “I'm not physically active but I'm thinking about starting” (contemplation); “I'm active occasionally” (preparation); “I'm active regularly and started in the last 6 months” (action); and “I'm active regularly and have been for longer than 6 months” (maintenance).

Statistical analyses Multiple one-way analyses of variance (MANOVA) with post hoc Scheffe were applied to explore differences between different diagnostic groups. Unpaired t-tests were executed to investigate the differences in motivation towards physical activity between: (1) men and women, (2) persons with a high versus a low educational level, (3) in- and out-patients. Differences across stages of change were tested with MANOVA with post hoc tests (Scheffe). Lastly, associations between variables were explored with Pearson correlations. Due to the exploratory nature of this study, we did not control for multiple testing but present the precise P-values so that the degree of ‘chance’ for each analysis is evident allowing readers to consider this when interpreting the current findings. Significance level was set at P b 0.05. SPSS 22.0 was used for data analysis (SPSS Inc, Chicago, IL).

218

D. Vancampfort et al. / Preventive Medicine 81 (2015) 216–220

Results

Discussion

Participants

General findings

A total of 294 (190♀) Belgian patients with SMI were recruited, including 129 persons with schizophrenia (43.9%), 96 individuals with major depressive disorder (32.6%), and 69 with bipolar disorder (23.5%). The exact number who declined participation is unclear due to insufficient data in several participating centres but based on extrapolation it is estimated that almost 25% of the eligible participants refused. No significant differences in demographical variables were found between participants and decliners for whom data were available. The mean (± SD) age was 43.6 ± 13.6 years and the mean (± SD) body mass index (BMI) 26.2 ± 4.9. Eighty-seven patients (29.6%) were outpatients. Overall, 186 (63.3%) participants were classified as having lower educational status. The mean (± SD) minutes of vigorous physical activity, moderate physical activity and walking per week was respectively 37.2 ± 71.0, 81.4 ± 113.0, and 173.0 ± 145.4. There were no significant differences in physical activity behaviour between the different diagnostic groups.

The current study is the first to our knowledge to investigate if there are differences in motivational regulations towards physical activity between people with schizophrenia, bipolar disorder and depression. Within this large sample of people with SMI, we found the only difference between the diagnostic groups is that people with affective disorders have higher levels of introjected regulations than people with schizophrenia. It might be that people with affective disorders experience more feelings of guilt or shame when they do not comply with demands they pose themselves or which are posed to them by significant others. The observed difference might however reflect differences in level of depressive symptoms in this group. We were unfortunately not able to investigate any associations with psychiatric symptomatology. When we considered other subgroup analyses we found no significant differences between male and female participants, between inand outpatients and between lower and higher educated participants. Thus, our results indicate that all these subgroups with SMI require the same input and support to engage, adopt and maintain physical activity. When we considered the entire SMI sample, the present study demonstrates that higher levels of identified and intrinsic motivation are observed in more advanced TTM stages of physical activity participation. Individuals with SMI in the preparation, action, and maintenance stages were also less amotivated than those in the (pre) contemplation stages. Individuals with SMI who are either engage on a long term in regular physical activity were also more intrinsic motivated than those who are just recently engaging in physical activity. Our results therefore suggest that the maintenance of frequent participation in physical activity over a longer period in people with SMI is reflective of both the quantity (i.e., lower levels of amotivation) and quality (i.e. a shift from controlled to autonomous regulations) of motivation. Interestingly, our study shows a clear association between more autonomous types of motivation and the amount of walking as well as moderate and vigorous intensity physical activity. Notably as well, levels of walking, moderate and vigorous physical activity was positively associated with extrinsic (i.e. identified regulation) and intrinsic regulations, irrespective of age and BMI. It might be that intrinsic motivation alone is not sufficient enough for some persons with SMI to sustain long-term regular physical activity engagement. Understanding and fully endorsing the personal value of physical activity (an extrinsic, identified regulation) seems to be equally important as being physically active for enjoyment.

Investigating differences in motivation according to diagnosis, gender, educational level, treatment setting and current level of physical activity People with bipolar disorder and major depressive disorder have higher levels of introjected regulations than people with schizophrenia. No significant differences were found in levels of other motivational regulations between people with schizophrenia, bipolar disorder and major depressive disorder (see Table 1). Also no significant differences were found between male and female participants, between in- and outpatients and lower and higher educated participants (data available upon request). Investigating differences in motivation according to stage of change Multivariate analyses showed significantly higher levels of amotivation and external regulations and lower levels of identified and intrinsic regulations in the earlier stages of change. No significant differences were found in the level of introjected regulations across the stages of change. Those in the maintenance stage had higher levels of intrinsic regulations than those in the action stage (see Table 2). Associations between the different SDT motivation types, physical activity, BMI and age The factors amotivation, external and introjected (only with moderate physical activity) regulation correlated negatively while identified and intrinsic regulations were positively associated with the IPAQ score. There were no significant associations of any motivation type with age or BMI. The r and P-values are for all associations between the different SDT motivation types, IPAQ scores, BMI and age are summarized in Table 3.

Limitations The current findings should be interpreted with some caution due to several methodological considerations. First, although the IPAQ is considered the most reliable self-report measure for physical activity in this group, there are concerns about the accuracy of recall of selfreport data (Soundy et al., 2014b). Second, the study contained no

Table 1 Means and standard deviations and differences in the BREQ-2 subscales by diagnostic category. Motivational type

Amotivation External regulation Introjected regulation Identified regulation Intrinsic regulation

Schizophrenia (n = 129)

Bipolar disorder (n = 69)

Major depressive disorder (n = 96)

M

SD

M

SD

M

SD

0.54 0.88 0.37a,b 2.60 2.67

0.80 1.0 0.55 0.90 1.11

0.62 0.79 1.59a 2.45 2.58

0.79 0.97 1.16 1.11 1.32

0.62 1.04 1.53b 2.58 2.54

0.82 0.95 1.03 0.9 1.08

MANOVA (*model significant at P b 0.05) with post hoc Scheffe when indicated (significance set here at P b 0.05), M = mean, SD = standard deviation. a Schizophrenia versus bipolar disorder. b Schizophrenia versus major depressive disorder.

F value

P-value

0.36 1.36 8.39 0.57 0.45

0.78 0.26 b0.001* 0.63 0.71

D. Vancampfort et al. / Preventive Medicine 81 (2015) 216–220

219

Table 2 Means and standard deviations and differences in the BREQ-2 subscales by stage of change. Motivational type

Amotivation External regulation Introjected regulation Identified regulation Intrinsic regulation

Precontemplation (n = 11)

Contemplation (n = 41)

Preparation (n = 60)

M

M

M

SD a,b,c

1.9 1.3c 0.8 1.4b,c 1.3b,c

0.9 1.3 1.0 0.7 1.0

SD d,e,f

1.2 1.3 1.5 2.0e,f 1.8e,f

SD a,d, g

1.1 1.0 1.0 1.0 0.8

Action (n = 72)

0.8 1.0 1.6 2.0g 1.9

0.7 0.9 1.1 0.9 0.9

M

Maintenance (n = 110) SD

b,e

0.4 0.9 1.3 2.7b,e 2.8b,e,h

0.6 0.9 1.0 0.9 0.8

M

F-value

P-value

31.3 4.6 2.7 26.6 46.5

b0.001* 0.001* 0.031* b0.001* b0.001*

SD c,f,g

0.2 0.6c 1.1c 3.0c,f,g 3.2c,f,g,h

0.4 0.9 1.0 0.7 0.7

MANOVA (*model significant at P b 0.05) with post hoc Scheffe when indicated (significance set here at P b 0.05), M = mean, SD = standard deviation. a Precontemplation versus preparation. b Precontemplation versus action. c Precontemplation versus maintenance. d Contemplation versus preparation. e Contemplation versus action. f Contemplation versus maintenance. g Preparation versus maintenance. h Action versus maintenance.

data on medication use and could therefore not determine any relationship between motivational regulations, physical activity participation and medication use. In the same way, we did not include data on psychiatric symptoms and on other lifestyle factors (e.g., smoking). Although only patients with a clinical global impression severity scale (Guy, 1976) score of 3 or less participated, excluding acute mental ill patients, these severity scores were not systematically collected. Fourth, it should be noted that we used a cross-sectional design, which means that the directionality of the relationships we observed cannot be deduced with certainty. For example, it is not possible to ascertain whether those in the later stages of change became more autonomous in the regulation of their physical activity behaviour over time as they increased their stage of change, or whether they reached the later stages of change because they were more autonomous from the start. Fifth, due to the lack of general population control data and Belgian normative values we were not able to compare the current data with such references. Nevertheless, allowing for these caveats our study is the largest of its kind and meets recent calls to better understand the motivational processes that may underlie the adoption of physical activity in the life of people with SMI (Vancampfort and Faulkner, 2014).

provide a means of examining the relationship between autonomy support, changes in behaviour and physical and mental health parameters over time. Third, future studies should identify significant moderating factors for the role of specific regulations on physical activity adherence such as previous health conditions, phase of illness or socio-cultural norms. Lastly, in contrast with previous research in the general population (Mullan and Markland, 1997) the current results identified no gender differences in reasons for being physically active. Future research should explore this difference with general population data more in detail.

Future research

Conflict of interest

An important future goal is to design lifestyle programmes that are aimed at promoting feelings of autonomous motivation in people with SMI. Grounded within SDT, lifestyle interventions should strive to foster perceptions of personal mastery, choice, and relevance, in all people with SMI (and this irrespective of their diagnosis) who are not active on a regular basis. Research adopting a longitudinal design would

We certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on us or on any organization with which we are associated. Dr. Vancampfort is funded by the Research Foundation — Flanders (FWO — Vlaanderen). The other authors declare that they have no conflicts of interest related to this study.

Conclusions The current findings suggest that in all people with SMI the level of identified and intrinsic motivation may play an important role in the adoption and maintenance of health promoting behaviours. Moreover, the study provides a platform for future research to investigate the relationships between autonomy support, motivational regulations and physical and mental health variables within lifestyle interventions for this population and considering the universality of the psychological needs irrespective of their socio-cultural background.

Acknowledgments Table 3 Pearson correlations between physical activity, motivation scores and demographical variables (n = 294).

Amotivation External regulation Introjected regulation Identified regulation Intrinsic regulation

IPAQ walking

IPAQ moderate

IPAQ vigorous

age

BMI

−0.38⁎⁎ −0.24⁎⁎ −0.08 0.43⁎⁎ 0.49⁎⁎

−0.30⁎⁎ −0.17⁎ −0.15⁎ 0.35⁎ 0.35⁎⁎

−0.27⁎⁎ −0.16⁎ −0.05 0.32⁎⁎ 0.36⁎⁎

0.04 0.04 0.10 0.01 −0.07

−0.02 0.11 −0.03 −0.02 −0.02

IPAQ = International Physical Activity Questionnaire, PA = physical activity. ⁎ P b 0.01. ⁎⁎ P b 0.001.

The authors would like to thank the following participating centres: 1) Psychiatrisch Ziekenhuis Duffel, Duffel, Belgium; (2) UPC KU Leuven, campus Kortenberg, Kortenberg, Belgium; (3) Algemeen Psychiatrisch Ziekenhuis Sint-Lucia, Sint-Niklaas, Belgium; (4) Psychiatrisch Centrum Bethanië, Zoersel, Belgium; (5) Psychiatrisch Ziekenhuis Asster, Melveren en Sint-Truiden, Belgium; (6) Psychiatrisch Ziekenhuis Heilig Hart, Ieper, Belgium; (7) Psychiatrisch Ziekenhuis Sint-Amandus, Beernem; (8). Openbaar Psychiatrisch Ziekenhuis Geel, Geel, Belgium; (9) Psychiatrisch centrum Sint-Jan de Deo, Gent, Belgium; (10) Psychiatrisch Ziekenhuis Sint-Alexius, Grimbergen, Belgium; (11) Openbaar Psychiatrisch Zorgcentrum, Rekem, Belgium; (12) Psychiatrisch Centrum Sint-Jan Baptist, Zelzate, Belgium; and

220

D. Vancampfort et al. / Preventive Medicine 81 (2015) 216–220

(13) Psychotherapeutisch Centrum Rustenburg, Brugge, Belgium; Psychosociaal Centrum Sint-Alexius, Elsene, Belgium; (14) Psychiatrisch Centrum OLVrouw van Vrede, Menen, Belgium; (15) UPC Sint-Kamillus, Bierbeek, Belgium. References American Psychiatric Association, 2000. Diagnostic and Statistical Manual of Mental Disorders. 4th edition. American Psychiatric Association, Washington DC. Craig, C.L., Marshall, A.L., Sjöström, M., Bauman, A.E., Booth, M.L., Ainsworth, B.E., Pratt, M., Ekelund, U., Yngve, A., Sallis, J.F., Oja, P., 2003. International physical activity questionnaire: 12-country reliability and validity. Med. Sci. Sports Exerc. 35, 1381–1395. Deci, E.L., Ryan, R.M., 2000. The “what” and “why” of goal pursuits: human needs and the self-determination of behavior. Psychol. Inq. 11, 227–268. Guy, W., 1976. Clinical global impressions scale. ECDEU Assessment Manual for Pharmacology. US Department of Health, Education, and Welfare, Rockville. Krämer, L.V., Helmes, A.W., Seelig, H., Fuchs, R., Bengel, J., 2014. Correlates of reduced exercise behaviour in depression: the role of motivational and volitional deficits. Psychol. Health 29 (10), 1206–1225. Long, B.J., Calfas, K.J., Wooten, W., Sallis, J.F., Patrick, K., Goldstein, M., et al., 1996. A multisite field test of the acceptability of physical activity counseling in primary care: Project PACE. Am. J. Prev. Med. 12 (2), 73–81. Markland, D., Tobin, V., 2004. A modification to the behavioural regulation in exercise questionnaire to include an assessment of amotivation. J. Sport Exerc. Psychol. 26, 191–196. Mullan, E., Markland, D., 1997. Variations in self-determination across the stages of change for exercise in adults. Motiv. Emot. 21, 349–362. Naci, H., Ioannidis, J.P., 2013. Comparative effectiveness of exercise and drug interventions on mortality outcomes: meta-epidemiological study. BMJ 347, f5577. Prochaska, J.O., DiClemente, C.C., 1983. Stages and processes of self-change of smoking: towards an integrative model of change. J. Consult. Clin. Psychol. 51, 390–395. Prochaska, J.O., Marcus, B.H., 1994. The transtheoretical model: applications to exercise. In: Dishman, R.K. (Ed.), Advances in Exercise Adherence. Human Kinetics, Champaign, IL, pp. 161–180. Rosenbaum, S., Tiedemann, A., Sherrington, C., Curtis, J., Ward, P.B., 2014. Physical activity interventions for people with mental illness: a systematic review and meta-analysis. J. Clin. Psychiatry 75 (9), 964–974.

Soundy, A., Stubbs, B., Probst, M., Hemmings, L., Vancampfort, D., 2014a. Barriers to and facilitators of physical activity among persons with schizophrenia: a survey of physical therapists. Psychiatr. Serv. 65 (5), 693–696. Soundy, A., Roskell, C., Stubbs, B., Vancampfort, D., 2014b. Selection, use and psychometric properties of physical activity measures to assess individuals with severe mental illness: a narrative synthesis. Arch. Psychiatr. Nurs. 28 (2), 135–151. Stubbs, B., Mitchell, A.J., De Hert, M., Correll, C.U., Soundy, A., Stroobants, M., Vancampfort, D., 2014. The prevalence and moderators of clinical pain in people with schizophrenia: a systematic review and large scale meta-analysis. Schizophr. Res. 160 (1–3), 1–8. Stubbs, B., Eggermont, L., Mitchell, A.J., De Hert, M., Correll, C.U., Soundy, A., Rosenbaum, S., Vancampfort, D., 2015. The prevalence of pain in bipolar disorder: a systematic review and large-scale meta-analysis. Acta Psychiatr. Scand. 131 (2), 75–88. Vancampfort, D., Faulkner, G., 2014. Physical activity and serious mental illness: a multidisciplinary call to action. Ment. Health Phys. Act. 7 (3), 153–154. Vancampfort, D., Correll, C.U., Probst, M., Sienaert, P., Wyckaert, S., De Herdt, A., Knapen, J., De Wachter, D., De Hert, M., 2013a. A review of physical activity correlates in patients with bipolar disorder. J. Affect. Disord. 145 (3), 285–291. Vancampfort, D., De Hert, M., Vansteenkiste, M., De Herdt, A., Scheewe, T.W., Soundy, A., Stubbs, B., Probst, M., 2013b. The importance of self-determined motivation towards physical activity in patients with schizophrenia. Psychiatry Res. 210 (3), 812–818. Vancampfort, D., Vansteenkiste, M., De Hert, M., De Herdt, A., Soundy, A., Stubbs, B., Buys, R., Probst, M., 2014. Self-determination and stage of readiness to change physical activity behaviour in schizophrenia. Mental Health and Physical Activity 7 (3), 171–176. Vancampfort, D., De Hert, M., Stubbs, B., Ward, P.B., Rosenbaum, S., Soundy, A., Probst, M., 2015a. Negative symptoms are associated with lower autonomous motivation towards physical activity in people with schizophrenia. Compr. Psychiatry 56, 128–132. Vancampfort, D., Madou, T., Moens, H., De Backer, T., Canhalst, P., Naert, P., Rosenbaum, S., Stubbs, B., Probst, M., 2015b. Could autonomous motivation hold the key to successfully implementing lifestyle changes in affective disorders? A multicentre cross sectional study. Psychiatry Res. 228 (1), 100–106. Walker, E.R., McGee, R.E., Druss, B.G., 2015. Mortality in mental disorders and global disease burden implications: a systematic review and meta-analysis. JAMA Psychiatry 72 (4), 334–341.