Abstract
Background Although schizophrenia is the fifth leading cause of disability-adjusted life years worldwide in people aged 15 to 44 years, the clinical evidence of physical therapy as a complementary treatment remains largely unknown.
Purpose The purpose of this study was to systematically review randomized controlled trials (RCTs) evaluating the effectiveness of physical therapy for people with schizophrenia.
Data Sources EMBASE, PsycINFO, PubMed, ISI Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Physiotherapy Evidence Database (PEDro), and the Cochrane Library were searched from their inception until July 1, 2011, for relevant RCTs. In addition, manual search strategies were used.
Study Selection Two reviewers independently determined study eligibility on the basis of inclusion criteria.
Data Extraction Reviewers rated study quality and extracted information about study methods, design, intervention, and results.
Data Synthesis Ten RCTs met all selection criteria; 6 of these studies addressed the use of aerobic and strength exercises. In 2 of these studies, yoga techniques also were investigated. Four studies addressed the use of progressive muscle relaxation. There is evidence that aerobic and strength exercises and yoga reduce psychiatric symptoms, state anxiety, and psychological distress and improve health-related quality of life, that aerobic exercise improves short-term memory, and that progressive muscle relaxation reduces state anxiety and psychological distress.
Limitations The heterogeneity of the interventions and the small sample sizes of the included studies limit overall conclusions and highlight the need for further research.
Conclusions Physical therapy offers added value in the multidisciplinary care of people with schizophrenia.
Schizophrenia is one of the most debilitating psychiatric disorders.1 It accounts for 1.1% of total disability-adjusted life years and for 2.8% and 2.6% of years lived with disability for men and women, respectively. In addition, it is the fifth leading cause of disability-adjusted life years worldwide in people who are 15 to 44 years old.2 Its lifetime prevalence and incidence range from 0.30% to 0.66% and from 10.2 to 22.0 per 100,000 person-years, respectively.3 According to criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), schizophrenia comprises both positive and negative symptomatology severe enough to cause social and occupational dysfunction.4 Positive symptoms reflect an excess or distortion of normal functions and include delusions, hallucinations, and disorganized speech and behavior. Negative symptoms reflect a reduction or loss of normal functions and include affective flattening, apathy, avolition, and social withdrawal. Mesolimbic dopaminergic hyperactivity is believed to be part of the underlying pathology associated with positive symptoms,5 but the pathophysiology of negative symptoms is poorly understood. Negative symptoms therefore remain a relatively treatment-refractory and debilitating component of schizophrenia.6
Once the diagnosis is made, antipsychotic drugs that block dopamine D2 receptors are the main treatment for people with schizophrenia.7 First-generation antipsychotics (eg, chlorpromazine, fluphenazine, and haloperidol) are effective in the management of psychotic symptoms but often lead to motor side effects. In the past 15 years, so-called second-generation agents (eg, amisulpride, aripiprazole, olanzapine, quetiapine, and risperidone) that less frequently cause motor side effects have been introduced for symptom management. Although second-generation antipsychotics are as effective as first-generation agents in managing positive symptoms, their promise of greater efficacy against negative and cognitive symptoms has not been borne out.8 Many people with schizophrenia continue to have persistent symptoms and relapses, particularly when they fail to adhere to prescribed medication regimens. This situation underlines the need for multimodal care, including psychosocial therapies, as an adjunct to antipsychotic medications to help alleviate symptoms and to improve adherence, functional outcomes, and health-related quality of life.9
Research on psychosocial approaches to treatment for people with schizophrenia has yielded incremental evidence of the efficacy of cognitive behavioral therapy, social skills training, family psycho-education, assertive community treatment, and supported employment.7–9 Additional research is needed to examine the aspects of therapeutic modalities that work and to identify the synergistic effects of combinations of interventions. Recently, there has been interest in the relative effectiveness of physical therapy interventions in multidisciplinary treatment for people with schizophrenia.10 The International Organization of Physical Therapy in Mental Health (formerly the International Council of Physiotherapy in Psychiatry and Mental Health) stated that in the multidisciplinary care of people with schizophrenia, physical therapy is intended to improve physical and mental health and health-related quality of life.11 For people with schizophrenia, an enhanced ability to cope with disease symptoms tends to improve health-related quality of life.12 Numerous physical therapy interventions are potentially effective in improving physical and mental health and health-related quality of life. The techniques most commonly used in daily clinical practice are aerobic and strength exercises, relaxation training, and basic body awareness exercises.10,13
People with schizophrenia, who are more likely to be less physically active than people in the general population14,15 and are consequently at high risk for chronic medical conditions associated with physical inactivity,16,17 have the same physical health needs as other people who are sedentary. For example, metabolic and cardiovascular diseases have become a major concern in people with schizophrenia.18 People with schizophrenia are 1.5 to 2 times more likely to be overweight, their risk for diabetes and hypertension is 2-fold higher, and dyslipidemia is 5 times more prevalent in people with schizophrenia than in people in the general population.19 The excess morbidity from cardiovascular diseases results in increased premature mortality—2 or 3 times as high as that in the general population.20,21 The mortality gap translates to a shortening of life expectancy by 13 to 30 years compared with that in the general population22,23 and is still widening.24,25 A previous systematic review of physical activity with or without diet counseling concluded that lifestyle interventions are feasible and effective in reducing weight and improving the obesity-related cardiometabolic risk profile in people with schizophrenia.26
Beneficial mental health effects from physical therapy interventions also have been reported. For example, earlier systematic reviews indicated that aerobic exercise reduces negative and positive symptomatology and alleviates secondary symptoms, such as depression, low self-esteem, and social withdrawal.27–30
The conclusions of these systematic reviews, however, were mainly based on data from uncontrolled trials, and the findings, therefore, should be interpreted with caution. More recently, a meta-analysis of aerobic exercise31 indicated that regular physical activity is possible for people with schizophrenia. Aerobic exercise can have beneficial effects on both the physical and mental health and the well-being of people with schizophrenia, although there is currently insufficient evidence to support or refute the use of aerobic and strength exercises as a complementary intervention.31 To our knowledge, no systematic reviews of relaxation training and basic body awareness exercises are available. The question of whether aerobic and strength exercises, relaxation training, and basic body awareness exercises are effective additions to the multidisciplinary management of schizophrenia, therefore, remains largely unanswered. Thus, the purpose of this systematic review was to evaluate the methodological quality of and summarize the evidence from randomized controlled trials (RCTs) examining the effectiveness of these physical therapy interventions in the multidisciplinary management of schizophrenia.
Method
Data Sources and Searches
A literature search was conducted according to the search strategy of Dickersin et al.32 No restrictions were made regarding the language of publication. EMBASE, PsycINFO, PubMed, ISI Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Physiotherapy Evidence Database (PEDro), and the Cochrane Library were searched from their inception until July 1, 2011, for RCTs. Medical subject headings included “schizophrenia” AND “physical therapy” OR “exercise” OR “relaxation” in the title, abstract, or index term fields. Two investigators independently screened the titles of the publications found in the databases and, if available, the abstracts of the publications as well. If either investigator believed that any published article potentially met the inclusion criteria or if there was inadequate information to make a decision, a copy of the article was obtained or the authors were contacted to obtain the necessary data.
The next phase of the search strategy involved searching for unpublished RCTs and for RCTs potentially overlooked or absent from the databases. This step involved manually searching the reference lists in all retrieved articles and the available systematic reviews for potential studies to locate unpublished or overlooked research. Furthermore, we searched Web sites housing details of clinical trials, theses, or dissertations. Citation indexing was used to track referencing of key authors in the field, and local experts were contacted for further information.
Study Selection
Inclusion in this review was restricted to studies of people with a diagnosis of schizophrenia or other types of schizophrenia spectrum psychoses (schizoaffective or schizophreniform disorder, excluding bipolar disorder and major depression with psychotic features) on the basis of any criteria, any length of illness, and any treatment setting. We did not exclude trials because of the age, nationality, or sex of the participants.
Types of interventions.
Studies were considered eligible for inclusion if they were RCTs comparing physical therapy interventions with a placebo condition, control intervention, or standard care. The experimental physical therapy interventions could comprise aerobic exercises, strength exercises, relaxation training, basic body awareness exercises, or a combination of these in accordance with the World Confederation for Physical Therapy position statement.33 A physical therapy intervention could be used alone or in conjunction with other interventions, with physical therapy being considered the main or active element. Interventions that included physical therapy in a multiple-component weight management program were excluded because the specific effects of the physical therapy intervention could not be addressed. Other interventions could include any of the following: pharmacotherapy, psycho-education, and cognitive-behavioral or motivational techniques related to exercise behavior. Standard care was defined as care that people would normally receive had they not been included in the research trial. Such care would include medication, hospitalization, community psychiatric nursing support, and outpatient care. For an RCT to be included, the experimental and comparison interventions must have had similar durations.
Types of outcomes.
Outcomes were grouped according to assessments of mental health, physical health, and health-related quality of life.
Data Extraction and Quality Assessment
Assessments of quality were completed independently by the 2 reviewers. Disagreements were resolved by discussion. If no consensus was achieved, a third reviewer made the final decision. Each study was evaluated with the previously validated 5-point Jadad scale34 to assess the completeness and quality of reporting of RCTs as well as to assess for potential bias in the trials. This widely used scale focuses on 3 dimensions of internal validity: quality of randomization, double-blinding, and withdrawals. This scale is the only published instrument that has been created according to psychometric principles.35,36 A score of 0 to 5 is assigned, with higher scores indicating higher quality in the conduct or reporting of a trial. A trial scoring at least 3 of 5 is considered to be of strong quality. A trial scoring below 3 is considered to be methodologically weak.
Data Synthesis and Analysis
Each study was assessed with a rating system originally developed by de Vet et al.37 This rating system provides a detailed evaluation of study methods and was used previously in systematic reviews for physical therapy.38,39 The rating system of de Vet et al37 considers criteria relevant to the practice of physical therapy, such as participant characteristics, sample size, description of interventions, and the validity and reliability of the chosen outcome measures. The 2 assessors independently reviewed each study on the basis of the specific criteria of this rating system. For each criterion, 3 ratings were available: pass (met the criterion), moderate (incompletely or partially met the criterion), and fail (did not meet the criterion); the fail rating also was assigned when no information about a specific criterion was provided in the publication. Each quality criterion was evaluated separately. At present, there are no clear decision rules for establishing cutoff scores for high- and low-quality studies with this tool; therefore, summary scores were not used.
A data collection form was developed and used by 1 reviewer (D.V.) to extract data from the included studies while a second reviewer (M.P.) cross-checked the extracted data. The data items extracted are shown in Table 1.
Data Extraction
Results
Study Selection
The initial electronic database search resulted in a total of 2,162 articles. Through additional manual searches of reference lists, searches of Web sites, and consultation of experts in the field, 1 other potentially eligible article was identified. After the removal of duplicates and screening of titles, abstracts, or full texts, 10 RCTs were included (Fig.).40–49 Reasons for exclusion are shown in the Figure. A list of excluded screened RCTs with reasons for exclusion is provided in the eTable. On the basis of the first full-text screening, we decided that there was too much heterogeneity in study designs and protocols to apply a formal meta-analysis.
Flow chart of systematic review inclusion and exclusion. CINAHL=Cumulative Index to Nursing and Allied Health Literature, PEDro=Physiotherapy Evidence Database, RCT=randomized controlled trial.
Participants
In total, 322 participants were included in the analyses. Except for participants in 2 studies40,41 published before the appearance of DSM-IV (the most recent edition of the Diagnostic and Statistical Manual of Mental Disorders, published in 1994), all participants were diagnosed with schizophrenia on the basis of DSM-IV criteria. Two studies included both inpatients and outpatients,43,45 2 studies concentrated solely on outpatients,42,47 and the other studies included only inpatients. The participants ranged in age from 18 to 63 years. With this strategy, both participants with first episodes and participants with chronic conditions were included. In most of the studies, the participants were men. Detailed information on the characteristics of the participants is provided in Table 2.
Details of Included Randomized Controlled Trialsa
Methodological Quality
Two of the included studies40,41 were considered to be of weak methodological quality (Tab. 2). Further details of the study characteristics are provided in Table 3. The 2 most common methodological concerns were limited sample size and lack of masking (“blinding”), especially of participants.
Critical Appraisal of Included Studiesa
Effectiveness of aerobic exercises, strength exercises, or both in the multimodal care of people with schizophrenia.
The investigators in 6 studies42,43,45–48 examined the effectiveness of aerobic exercises, strength exercises, or both in multidisciplinary standard care for people with schizophrenia. All 6 studies were considered to be of strong methodological quality. In 1 study43 of 3 studies42,43,46 examining the effectiveness of these exercises for positive and negative symptoms, the reductions found were significant. In the studies of Duraiswamy et al43 and Behere et al,46 aerobic exercises, strength exercises, or both were compared with yoga as a complementary intervention. Participants practicing yoga reported significantly greater reductions in positive and negative symptoms. Health-related quality of life improved only after yoga.43 The investigators in 3 studies42,45,47 examined changes in aerobic fitness, muscular fitness, or both; 2 studies42,45 included the Six-Minute Walk Test; and 1 study47 included incremental cycle ergometry. Although both studies including the Six-Minute Walk Test revealed increases in the distance covered by their respective participants, only participants in the study of Marzolini et al45 increased their distance walked significantly. Although participants performing 30 minutes of aerobic training, strength training, or both 3 times per week for 3 months improved their maximal oxygen uptake, as measured with incremental cycle ergometry, this improvement was not significant compared with that in a control condition.47 In contrast, participants performing aerobic training, strength training, or both improved their short-term memory, a result that was related to an increase in hippocampal volume. Marzolini et al45 reported a significant increase in strength but no improvement in blood pressure. Changes in body mass index were examined in 2 studies42,45; no effect was found. Vancampfort et al48 reported significant reductions in state anxiety and psychological distress and improvements in subjective well-being after single sessions of aerobic exercise and yoga.
Effectiveness of progressive muscle relaxation in the multimodal care of people with schizophrenia.
Three of the 4 studies examining the effectiveness of progressive muscle relaxation40,41,44,49 revealed significant reductions in anxiety. In the methodologically weak study of Pharr and Coursey,41 no significant differences were found for 7 progressive muscle relaxation sessions (20 minutes each) compared with either 7 electromyographic feedback sessions or 7 sessions of reading exercises. The RCTs of Hawkins et al40 (methodologically weak) and Vancampfort et al49 (methodologically strong) revealed significant reductions in state anxiety. In the study of Hawkins et al,40 state anxiety reductions were associated with fewer hospital admissions in the year after the intervention; in the study of Vancampfort et al,49 state anxiety reductions were associated with reduced psychological distress and improved perceived well-being.
Effectiveness of basic body awareness exercises in the multimodal care of people with schizophrenia.
The effectiveness of basic body awareness exercises for people with schizophrenia was not investigated in any of the included RCTs.
Adverse Effects
Duraiswamy et al43 indicated that for both aerobic and strength exercises and yoga, no significant differences in extrapyramidal symptoms and abnormal involuntary movements as potential adverse effects were found. Pajonk et al47 also reported finding no adverse events during the testing period.
Discussion
General Findings
This systematic review explored the efficacy of aerobic and strength exercises, relaxation training, basic body awareness exercises, or a combination of these as an adjunct treatment for people with schizophrenia. In general, the included RCTs showed that, in particular, aerobic and strength exercises and progressive muscle relaxation can have an impact on mental health outcomes, such as mental state, state anxiety, and psychological distress. Aerobic and strength exercises also have a limited effect on physical health outcomes, such as aerobic and muscular fitness, with no adverse effects. No RCTs demonstrating the added value of basic body awareness exercises were available. An interesting finding was that when aerobic and strength exercises were compared with other types of exercises, such as yoga (combining breathing exercises, relaxation techniques, and body postures), the benefits of aerobic and strength exercises were not as profound. Overall, the present review indicated that physical therapy as an adjunct treatment might improve a person's mental and physical health and health-related quality of life.
Six articles26–31 identified and reviewed existing research studies in which physical activity was used as a form of adjunct treatment for people with schizophrenia. Four of these reviews27–30 included various research designs, such as qualitative, quantitative, and mixed methods. The previously reported results are in line with those of the present review. Faulkner and Biddle,27 Faulkner,28 Ellis et al,29 and Holley et al30 indicated that physical activity can improve psychological health and psychological well-being in people with schizophrenia, and Vancampfort et al26 indicated that physical activity with or without diet counseling is feasible in reducing weight and improving the obesity-related cardiometabolic risk profile. Additionally, all of these reviews stressed the need for more methodologically rigorous research, given that nonrandomized designs were used in most of the studies. Our data confirm the findings of Gorczynski and Faulkner31 in a recent review of 3 randomized controlled studies investigating physical activity in people with schizophrenia; the findings suggested that calls for more methodologically rigorous research are starting to be addressed.
To our knowledge, the present review is the first to offer evidence for the effectiveness of aerobic and strength exercises in reducing state anxiety and psychological distress; for the effectiveness of aerobic and strength exercises in improving short-term memory; for the effectiveness of progressive muscle relaxation as an adjunct intervention to reduce state anxiety and psychological distress; and for the effectiveness of yoga in reducing positive and negative symptoms, state anxiety, and psychological distress. The cognitive improvements observed after aerobic exercise seemed to be related to exercise-induced neurogenesis in the hippocampus.
The ability to deal with state anxiety and psychological stress during aerobic exercise, progressive muscle relaxation, and yoga might be of particular relevance for people with schizophrenia. First, there is a general consensus that worsening of schizophrenia symptoms is related to stress and anxiety.50 Second, people with schizophrenia experience difficulties in coping with stress and anxiety and possess a relatively limited repertoire of coping strategies.51 The use of alcohol, nicotine, or illegal drugs, which is common in people with schizophrenia,18 has been suggested to be an attempt to alleviate or to cope with psychiatric symptoms, unpleasant affective states, and feelings of state anxiety and psychological distress.52 The limited benefit of such behaviors supports the need to provide other, more healthful methods to regulate the variability of subjective well-being. The present review showed that aerobic exercise, progressive muscle relaxation, and yoga might be easily learned, healthful alternatives for symptom, stress, and anxiety regulation.
Limitations
Although we believe that this systematic review is the first to investigate the effectiveness of several physical therapy interventions in people with schizophrenia, the review does have some limitations that need to be acknowledged. First, as with any systematic review, there is a potential for selection bias; however, we used a comprehensive search strategy. In addition, 2 independent reviewers analyzed the research data, and reasons for study exclusions were clearly documented. Second, performance bias may limit our findings. None of the included studies were double-blind studies. The reported results therefore may exaggerate estimates of treatment effects.53 Although researchers may not always be able to mask participants to physical therapy interventions to remove the chance of performance bias, every attempt should be made to collect research data in a masked manner. In the present review, only 4 of the included studies were single-blind studies.42,43,46,47 Third, the heterogeneity among the RCTs, particularly with regard to the frequency and duration of the experimental intervention and the chosen control or comparison intervention, was a challenge in the present review. This diversity, as well as the small sample sizes and other methodological gaps in many of the included studies, limited overall conclusions and highlighted the need for further research.
Implications for Practice
The results of this systematic review support the use of physical therapy in the multidisciplinary care of people with schizophrenia. However, clear guidance regarding the type of intervention and optimal dose is limited by the small number of available RCTs and the variability of the interventions themselves in terms of frequency, intensity, and duration. Physical therapists, therefore, should assess the types of exercises or techniques that would best fit a person's preferences. Along with emphasis on the benefits of physical therapy, careful attention to several barriers that prevent people from participation in physical therapy is needed. Before offering any kind of program, physical therapists should consider and address psychiatric symptoms, antipsychotic medication side effects, and structural barriers. In addition to addressing barriers, physical therapists should structure programs to be informative, continuously motivate people to participate, and allow them to progress at their own pace. To achieve these goals, the Organization of Physical Therapy in Mental Health54 recommends that physical therapists be trained in recognizing and adequately addressing symptoms of severe mental illness, physical comorbidities, and side effects of medications. Physical therapists would benefit from acquiring various cognitive-behavioral and motivational skills to help their patients participate in physical therapy programs.
Implications for Future Research
There is a clear need for well-designed RCTs examining physical therapy interventions as adjunct treatment for people with schizophrenia. Trials should be large enough to be clinically meaningful, should be adequately powered, and should include valid and reliable outcome measures. Furthermore, attempts should be made to mask raters to a person's clinical status, group allocation, and treatment condition; to mask therapists to outcome measures; and, when possible, to mask participants as well. Researchers should consider the findings of this systematic review when designing trials and should attempt to overcome the limitations of the RCTs presented. Because most of the RCTs retrieved in this review did not have longitudinal follow-up to determine whether the improvements observed after physical therapy were maintained over time, the question of whether short-term benefits result in long-term changes remains largely unanswered. Therefore, long-term trials are needed to further enhance knowledge about physical therapy prescription for people with schizophrenia.
Future research should clearly define the exact nature of a physical therapy program, with special attention to the duration, frequency, and intensity of any intervention reported. Adherence, participants' characteristics (age, sex, illness duration, and medication protocol), and adverse events should be clearly described. Outcome measures should include measures relevant to schizophrenia-related symptoms and broader clinical outcomes, such as health-related quality of life, hospital admissions, and behavioral outcomes (eg, through increasing rates of abstinence from alcohol, nicotine, or illegal drugs). For example, future studies could examine whether implementing self-managed aerobic exercise and relaxation techniques increases rates of abstinence from substance abuse and whether any effects of these interventions are mediated by decreases in psychological distress and state anxiety and increases in perceived well-being during or after these activities.
Future research also needs to examine potential physiological mechanisms (eg, increased norepinephrine, serotonin, and beta-endorphin levels and increased parasympathetic activity) or psychological mechanisms (eg, increased self-efficacy and distraction) that could be responsible for an improved mental health state and reduced state anxiety and psychological stress.55 Future studies on aerobic exercise in people with schizophrenia also should confirm whether their brains retain a degree of plasticity in response to exercise.
Finally, no RCTs investigated the role of basic body awareness exercises. The use of basic body awareness exercises as an adjunct treatment may be highly relevant for people with schizophrenia. Various body experience distortions have been observed in schizophrenia; these include symptoms of disembodiment, such as not feeling comfortable in one's body, or disintegration, as if one's body were being torn apart.56,57 Previous qualitative research58,59 in people with schizophrenia reported improvements in body balance and postural control, increased self-esteem, and an improved ability to think after a physical therapy program based on basic body awareness exercises. However, rigorous research is needed before basic body awareness therapy can be considered effective in multidisciplinary treatment for people with schizophrenia.
Conclusion
This systematic review demonstrated that specific physical therapy interventions, including aerobic and muscle strength exercises, progressive muscle relaxation, and yoga, resulted in beneficial outcomes for psychiatric symptoms, psychological distress, state anxiety, health-related quality of life, and aerobic and muscular fitness. Future research into specific features of physical therapy interventions, such as tailoring interventions to the needs of people with schizophrenia, may contribute to evidence for the efficacy of physical therapy for people with schizophrenia.
Footnotes
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Mr Vancampfort, Ms Skjaerven, Dr Catalán-Matamoros, Dr Lundvik-Gyllensten, and Dr Hert provided concept/idea/research design. Mr Vancampfort, Dr Probst, Ms Skjaerven, Dr Catalán-Matamoros, Dr Gómez-Conesa, and Dr Hert provided writing. Mr Vancampfort, Ms Skjaerven, Dr Catalán-Matamoros, and Dr Gómez-Conesa provided data collection. Mr Vancampfort, Ms Skjaerven, and Dr Catalán-Matamoros provided data analysis. Mr Vancampfort provided project management. Dr Probst provided participants. Dr Probst and Dr Gómez-Conesa provided facilities/equipment. Dr Probst, Dr Lundvik-Gyllensten, Dr Gómez-Conesa, and Mr Ijntema provided institutional liaisons. Dr Probst, Ms Skjaerven, Dr Lundvik-Gyllensten, and Dr Gómez-Conesa provided consultation (including review of manuscript before submission).
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Mr Vancampfort was the first author of 2 of the assessed studies. Dr De Hert and Dr Probst were coauthors of 2 of the included studies. The other authors declare that they have no conflict of interest related to the present review.
- Received July 8, 2011.
- Accepted August 30, 2011.
- © 2012 American Physical Therapy Association
References
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