Issues in Mental Health Nursing, 35:851–863, 2014 Copyright © 2014 Informa Healthcare USA, Inc. ISSN: 0161-2840 print / 1096-4673 online DOI: 10.3109/01612840.2014.924044
A Systematic Review of Interventions to Reduce Stress in Adolescence Lynn Rew, EdD, RN, AHN-BC, FAAN, Karen Johnson, PhD, RN, and Cara Young, PhD, RN, FNP-C The University of Texas at Austin, School of Nursing, Austin, Texas, USA
Adolescence can be a stressful developmental phase, placing youth at risk for negative health outcomes. Evidence-based interventions are crucial to helping adolescents manage stress; yet, most of the literature on adolescent stress is observational and descriptive. We systematically reviewed the literature on stress management interventions for adolescents and found there is evidence to support the effectiveness of interventions that aim to develop cognitive skills among adolescents; however, most studies had small samples and relied on different operational definitions of outcomes. Few included biological indicators of stress. Further study is needed to develop interventions to enhance adolescents’ capacity to manage stress.
There is ample evidence that adolescents experience stress as they develop and respond to myriad stimuli from their environments. The second decade of life is the most rapid developmental period after infancy, and during this time of multiple transitions, adolescents experience stress in several domains of their lives. The physical development that characterizes adolescence often creates anxiety and feelings of stress (Ruuska, Kaltiala-Heino, Koivisto, & Rantanen, 2003, p. 218). Adolescents are particularly vulnerable to stress-related depression, owing to their developing mesocorticolimbic dopamine systems (Andersen & Teicher, 2008). Similarly, emotional and social transitions associated with the shift in parent–child relationships, new school environments, and the realignment of the adolescent with their peers’ larger social systems have been shown to be associated with stress and anxiety in adolescents (Grills-Taquechel, Norton, & Ollendick, 2010; Raudino, Fergusson, & Horwood, 2013; Sontag & Graber, 2010). In addition to these expected developmental stressors, some adolescents experience chronic stress (e.g., poverty, disrupted
Address correspondence to Lynn Rew, University of Texas at Austin, School of Nursing, 1700 Red River, Austin, Texas 78701, USA. E-mail: [email protected]
family and home environments) that can lead to a number of adverse health outcomes. For example, the number of adolescents aged 12–17 years living in low-income poor families is rising: in 2011, 41% were from low-income families, while 19% were from poor families (Addy, Engelhardt, & Skinner, 2013). Evans and Kim (2012) found that adolescents 17 years of age who spend longer periods of their childhood (birth to 9 years) living in poverty had higher levels of chronic physiologic stress. Across this range of stressful experiences, however, we know very little about interventions that successfully reduce or prevent deleterious symptoms of stress in adolescents. Thus, the purpose of this paper is to report the findings from a systematic review of the literature on interventions to reduce stress in adolescents aged 10–19 years. This age range was selected because it reflects the definition of adolescence provided by the World Health Organization (2013). This definition is often cited in the literature pertaining to adolescence and has a global understanding.
BACKGROUND The concept of stress was first introduced into health-related literature in 1978, when Hans Selye coined the terms stressor and stress to denote cause and effect of what he had described as the ‘General Adaptation Syndrome (GAS)’. Selye noted that the use of the word in engineering ‘to denote the effects of a force acting against resistance’ were comparable with the human responses he had observed and recorded as the GAS (Selye, 1978, p. 45). Lazarus and Folkman (1984) later described stress as a transaction between a stimulus in the environment and a person. These theorists focused on cognitive appraisal of the stimulus as perceived harm or loss, threat, or challenge and the response of the person as the coping process. In 1999, Lazarus published a synthesis of stress and emotion, in which he wrote, ‘The three concepts, stress, emotion, and coping, belong together and form a conceptual unit, with emotion being the superordinate concept because it includes stress and coping’ (p. 37).
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In contrast to approaching the effects of stress as pathogenic, or causing a disease, Antonovsky (1979) introduced the term salutogenesis to the literature on stress, by which he meant those factors that enabled people to thrive in the face of numerous and enormous threats. One of the central tenets of Antonovsky’s conceptualization of stress is the concept of sense of coherence. Sense of coherence refers to an individual’s ‘enduring though dynamic feeling of confidence that one’s internal and external environments are predictable and that there is a high probability that things will work out as well as can reasonably be expected’ (Antonovsky, 1979, p. 123). In recent years, stress has become more clearly understood in terms of ‘allostatic load’, the physiological dysregulation that occurs with chronic stress (Gallo, Jim´enez, Shivpuri, de los Monteros, & Mills, 2011). Allostatic load refers to the burden associated with cumulative experiences of stress as it changes the hypothalamic-pituitary-adrenal (HPA) axis. Such changes, or dysregulation, of the HPA system can have ‘powerful and enduring effects on the brain’ (Katz, Sprang, & Cooke, 2012, p. 471). Adverse childhood experiences, such as maltreatment and chronic stress have been shown to create long-lasting changes in endocrine, immune, and nervous systems, including underdevelopment of the prefrontal cortex (Danese & McEwen, 2012). Several stress reduction approaches have been developed for adults. Mindfulness-based studies, for example, have been shown to be effective in reducing stress in patients with cancer (Lengacher et al., 2012; Matchim, Armer, & Stewart, 2011) and in reducing depressive symptoms in persons with mental disorders (Barnhofer, Crane, Hargus, Amarasinghe, Winder, & Williams, 2009; Klainin-Yobas, Cho, & Creedy, 2012).
Sources of Stress in Adolescents Stressors in adolescents range from the stress of daily living (also known as hassles) to the development of post-traumatic stress disorder (PTSD) and complex traumatic stress reactions that can lead to significant emotional dysregulation and stressrelated diseases (Ford, 2011; Gerson & Rappaport, 2013). Daily hassles, such as school, family, and friends have been identified by adolescents as sources of stress (Wright, Creed, & Zimmer-Gembeck, 2010). School is frequently identified as a major source of stress for adolescents (LaRue & Herrman, 2008). In a study of 216 adolescents who took part in a longitudinal study, Rew, Tyler, Fredland, and Hannah (2012) found that the top four concerns of adolescents in high school were education, relationships, expectations, and future. Other things that these adolescents worried about included the economy, future careers, sexuality, and death. Finally, evidence suggests that perceived racial and ethnic discrimination is related to distress in youths of color (Fisher, Wallace, & Fenton, 2000).
Stress Outcomes Research has shown that stress in adolescence is related to health-risk behaviors, such as alcohol and other substance use (King, Molina, & Chassin, 2009; Wills, Sandy, Yaeger, Cleary, & Shinar, 2001), as well as smoking (Finkelstein, Kubzansky, & Goodman, 2006). A study of 451 adolescents, ages 13–17 years, with alcoholic parents and a matched control found that stressors were related to adolescents’ alcohol use and predicted short-term increases in use (King, Molina, & Chassin, 2009). Stress has also been associated with poor dietary habits in adolescents. For example, the Health and Behavior in Teenagers Study (HABITS), which sampled over 4,000 diverse students in public schools (mean age = 11.83 years), found that greater stress was related to eating more fatty foods and snack foods, and fewer fruits and vegetables (Cartwright, Wardle, Simon, Croker, & Jarvis, 2003). Previous studies of stress in adolescents included those that addressed coping with specific diseases, such as HIV/AIDS (Lewis & Brown, 2002; Sibinga, Stewart, Magyari, Welsh, Hutton, & Ellen, 2008), asthma (Murdock, Greene, Adams, Hartmann, Bittinger, & Will, 2010; Peeters, Boersma, & Koopman, 2008), and diabetes (Antal, Wysocki, Canas, Taylor, & Edney-White, 2010; McCarty et al., 2010). Other studies addressed stress and coping in more general terms, such as exploring the effects of art on reducing stress in hospitalized children and adolescents (Eisen, Ulrich, Shepley, Varni, & Sherman, 2008). METHODS This systematic review of the literature was guided by the 27 items on the checklist of the Preferred Reporting Items for Systematic reviews and Meta-Analyses, known as PRISMA (Liberati et al., 2009). The purpose of PRISMA is to ensure completeness and transparency in the reporting of literature reviews. Research Questions The review of literature was designed to answer the following research questions: 1. What types of research design were used in studies of stress management interventions for adolescents? 2. What were the characteristics (i.e., content, setting/method, length) of stress reduction interventions for adolescents? 3. What were the stress-related outcomes of stress reduction interventions reported for adolescents? The retrieval and inclusion of information reported in this systematic literature review was guided by the four phases of PRISMA: ‘identification, screening, eligibility, and included’ (Liberati et al., 2009, p. 68).
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Identification Search engines used to identify the relevant literature were Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Education Resources Information Center (ERIC), MEDLINE, PsychArticles, PsycInfo, PUBMED, and Cochrane. Two searches were conducted with each search engine using the following terms: (1) Child + stress + stress reduction and (2) Adolescent + stress + stress reduction. After the initial reviews were completed, we performed a hand search of the references in the articles we found through our databases. We reviewed these additional references and included all eligible articles in this review. Screening All ‘hits’ were screened for duplicates and whether or not they met the inclusion/exclusion criteria. Those that did not meet the eligibility and inclusion criteria or were duplicates, were removed from the final dataset. Eligibility A final set of 17 articles was deemed eligible for the systematic review. The same inclusion/exclusion criteria were used to determine eligibility of articles that surfaced during the hand search. The set of eligible articles were then included in the systematic review. Inclusion criteria were that the article was peerreviewed, written in English, published between 1988 and 2013, addressed an intervention to reduce stress in adolescents (ages 10–19), and included a measure of stress as an outcome. Exclusion criteria included books, dissertations, reports, or clinical guidelines. Procedure After identifying, screening, and determining eligibility of the lists of articles, we conducted hand searches of all articles that were to be included in the report. This then determined the final number of articles for review. We then extracted data from the selected articles using a spreadsheet with headings to match our research questions; each article was read independently by at least two of the authors to extract the data. Data were then analyzed and synthesized to comprise this report. FINDINGS Figure 1 shows the summary of articles included in each phase of data identification, screening, eligibility, and inclusion. The search using the terms child + stress + stress reduction yielded 259 articles and the search using the terms adolescent + stress + stress reduction yielded 158 articles, for a total of 417. After removing duplicates, a total of 326 articles remained. Abstracts of the 326 articles were then screened for eligibility and inclusion in the penultimate sample of 14 published articles. Three more articles were retrieved
Total citations (n = 417) Duplicates removed (n = 91)
Abstracts reviewed (n = 326) Excluded by title or Abstract contents (n = 312)
Articles reviewed (n = 14)
Additional articles from hand searches (n = 3)
Final articles reviewed (n = 17) FIGURE 1 Flowchart of literature searches on stress reduction interventions for adolescents.
from our hand search of references for a total final sample of 17 articles that were included in the review. Study Designs Nine of the studies (60%) used randomized designs with the unit of randomization being at the individual level for five of the studies (Barnes, Treiber, & Davis, 2001; Davey & Neff, 2001; Hains & Szyjakowski, 1990; Weigensberg et al., 2009; Wright, Gregoski, Tingen, Barnes, & Treiber, 2011) and the group level (e.g., school, classroom) for four studies (Barnes, Treiber, & Johnson, 2004; Jellesma & Cornelis, 2012; White, 2012; Yahav & Cohen, 2008). Those that randomized at the group level had two of five schools or classrooms in the study to randomly assign to intervention or control conditions, which was not adequate to ensure confounders would be equally distributed across the sample (Barnes et al., 2004; Jellesma & Cornelis, 2012; White, 2012; Yahav & Cohen, 2008). Furthermore, random assignment at the classroom level introduced the potential for contamination of control groups housed in the same school as the intervention groups (Yahav & Cohen, 2008). Three of the four studies that randomized at the group level reported a data analysis plan that accounted for clustering (Barnes et al., 2004; Jellesma & Cornelis, 2012; Yahav & Cohen, 2008). Seven studies employed quasi-experimental designs, five of which had intervention and control/comparison groups (Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; Norlander, Moas, & Archer, 2005; Rauhala, Alho, Hanninen, &
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Helin, 1990), whereas two used single-group pre/post-test designs (Grosswald, Stixrud, Travis, & Bateh, 2008; Tan & Martin, 2012). Finally, one study employed a mixed methods design (Sibinga, Kerrigan, Stewart, Johnson, Magyari, & Ellen, 2011). Sample Sizes and Attrition Across studies, baseline sample sizes ranged from 10 to 255, with four studies having sample sizes smaller than 25 (Grosswald et al., 2008; Hains & Szyjakowski, 1990; Tan & Martin, 2012; Weigensberg et al., 2009); six studies having sample sizes between 25 and 100 (Barnes et al., 2001; Davey & Neff, 2001; Jellesma & Cornelis, 2012; Norlander et al., 2005; Rauhala et al., 1990; Sibinga et al., 2011), and seven studies having sample sizes larger than 100 (Barnes et al., 2004; Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; White, 2012; Wright et al., 2011; Yahav & Cohen, 2008). Only one study reported doing a power analysis (White, 2012). Most studies did not address attrition rates or amount of missing data between baseline and final measures; those that did, reported attrition rates between 0% (Jellesma & Cornelis, 2012; Weigensberg et al., 2009) and 36% (Barnes et al., 2004) and up to 42% missing data (Sibinga et al., 2011). It was not always clear whether authors were reporting attrition rates or amounts of useable data (i.e., missing data from youth who did not drop out of the study). Sample Demographics A diverse range of youth was included across studies. Average age ranged from 9.9 years, which we rounded up to 10 to meet our inclusion criteria (White, 2012) to 17.4 (Broderick & Metz, 2009), and studies included youth anywhere from 6 years old (Davey & Neff, 2001) to 21 years old (Sibinga et al., 2011). Most study samples were relatively evenly split between males and females (n = 11). Some studies focused exclusively on males (Hains & Szyjakowski, 1990; Rauhala et al., 1990) or females (Broderick & Metz, 2009; White, 2012). Two others had samples that were over 75% male (Grosswald et al., 2008) or female (Sibinga et al., 2011). Four studies were conducted outside of the USA, specifically the Netherlands (Jellesma & Cornelis, 2012), Sweden (Norlander et al., 2005), Australia (Tan & Martin, 2012), and Israel (Yahav & Cohen, 2008). Of the 13 studies conducted in the USA, over half of these (n = 8) had samples that were predominantly (≥60%) youth of color (Barnes et al., 2004; Barnes et al., 2001; Davey & Neff, 2001; Elder et al., 2011; Grosswald et al., 2008; Sibinga et al., 2011; Weigensberg et al., 2009; Wright, 2011). In studies based in the USA, the diversity of samples is a strength in terms of focusing on populations that may face higher levels of stress (e.g., due to discrimination, poverty), but also may limit generalizability to the broader population of US youth. Finally, many studies focused on general samples of school-based youth, while others focused on specific populations of youth for whom stress management is particularly crucial, including youth at risk for high blood pressure
(Barnes et al., 2001; Wright et al., 2011), living with their families in homeless shelters (Davey & Neff, 2001), living with ADHD (Grosswald et al., 2008), residing in rehabilitation centers (Rauhala et al., 1990), and living with HIV (Sibinga et al., 2011). Intervention Characteristics Content The content of the stress reduction interventions reviewed can be placed into four broad categories: (1) mindfulness/awareness; (2) Transcendental meditation (TM); (3) relaxation exercises; and (4) life skills training. Mindfulness/awareness techniques emphasize non-judgmental attention to the present moment (i.e., ‘mindfulness’) and were the most frequent techniques reported (n = 8; Broderick & Metz, 2009; Davey & Neff, 2001; Jellesma & Cornelis, 2012; Sibinga et al., 2011; Tan & Martin, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Several studies used a modified version of the standard mindfulness-based stress-reduction program (Kabat-Zinn, 1982) that had been tailored to the developmental and functional needs of the adolescent populations with whom they were working (Broderick & Metz, 2009; Sibinga et al., 2011; Tan & Martin, 2012). Another frequently utilized mindfulness strategy was the use of awareness exercise activities, such as breathing and yoga postures (Davey & Neff, 2001; Jellesma & Cornelis, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Four studies reported using the standard TM format (Barnes et al., 2001; Barnes et al., 2004; Elder et al., 2011; Grosswald et al., 2008). TMTM is a registered, trademarked technique of the Maharishi Foundation USA and fundamentally differs from mindfulness-based techniques in that TM encourages the practitioner to do nothing to control their mind or direct their attention in any particular direction. One of the interventions tested by Wright and colleagues (2011) combined components of TM and mindfulness-based techniques by utilizing the structure of TM (i.e., twice daily 10 min sessions) but instructed their participants to focus on the movement of the diaphragm (i.e., awareness). Relaxation exercises in the form of stretching, progressive relaxation, visualization-based relaxation, and muscle contraction and release were present in six of the reviewed interventions (Davey & Neff, 2001; Jellesma & Cornelis, 2012; Norlander et al., 2005; Rauhala et al., 1990; Weigensberg et al., 2009; Yahav & Cohen, 2008). The final category of intervention content, termed ‘life skills training’ by Wright and colleagues (2011), provided didactic content related to stress and coping. These interventions focused on teaching participants to identify sources of stress, evaluate their emotional response to identified stressors, and employ strategies to minimize the effect of stressors (e.g., problem-solving, conflict resolution, talking about their feelings, and anger management) (Hains & Szyjakowski, 1990; Wright et al., 2011; Yahav & Cohen, 2008). The majority of interventions (n = 10) included some form of home practice/homework for participants to complete between
INTERVENTIONS TO REDUCE STRESS IN ADOLESCENCE
intervention sessions (Barnes et al., 2001; Barnes et al., 2004; Broderick & Metz, 2009; Davey & Neff, 2001; Elder et al., 2011; Grosswald et al., 2008; Tan & Martin, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Several unique intervention components were also identified within the reviewed studies. Rauhala and colleagues (1990) were distinctive in their use of aerobic physical activity and sauna sessions, and Yahav and Cohen (2008) incorporated biofeedback technology within their life skills training and relaxation intervention. Settings and Method of Delivery The setting of intervention delivery was closely linked with location and method of subject recruitment. For example, Davey and Neff (2001) recruited participants from two family-shelter facilities, and the group intervention was conducted at these shelters. The majority of studies (n = 12) delivered group interventions in classroom-based settings (Barnes et al., 2001; Barnes et al., 2004; Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; Grosswald et al., 2008; Jellesma & Cornelis, 2012; Norlander et al., 2005; Tan & Martin, 2012; White, 2012; Wright et al., 2011; Yahav & Cohen, 2008). Of these classroom-based studies, only one (White, 2012) did not deliver the intervention within the standard school day; group sessions were conducted immediately after the school day had ended. The setting of intervention delivery was not specified in five of the reviewed articles. Rauhala et al. (1990) conducted their intervention with adolescent boys residing in a community rehabilitation home for young offenders, and the setting of delivery is implied as within this setting. Sibinga et al. (2011) and Tan and Martin (2012) utilized clinic-based recruitment strategies, but the setting of intervention delivery was not specified for their group interventions. Hains and Szyjakowski (1990) conducted both group and individual intervention sessions with participants from an all-male college-preparatory parochial school, but the setting of delivery was not specified. Weigensberg et al. (2009) did not state where they conducted their intervention consisting of individual weekly sessions. Intervention Length Total length of interventions ranged from 1 month (4 weeks) (Davey & Neff, 2001; Norlander et al., 2005; Weigensberg et al., 2009) to 4 months (16 weeks) (Barnes et al., 2004; Elder et al., 2011; Rauhala et al., 1990). The intervention length most frequently reported (n = 4) was 2 months (Barnes et al., 2001; DeWolfe & Saunders, 1995; White, 2012; Yahav & Cohen, 2008). Two months was also the median of intervention length. Hains and Szyjakowski (1990) were the only researchers who failed to report intervention duration. The intervention consisted of three phases, each of which contained one group session (1-h each) and two individual sessions (30–40 min each, last individual session
A Systematic Review of Interventions to Reduce Stress in Adolescence Lynn Rew, EdD, RN, AHN-BC, FAAN, Karen Johnson, PhD, RN, and Cara Young, PhD, RN, FNP-C The University of Texas at Austin, School of Nursing, Austin, Texas, USA
Adolescence can be a stressful developmental phase, placing youth at risk for negative health outcomes. Evidence-based interventions are crucial to helping adolescents manage stress; yet, most of the literature on adolescent stress is observational and descriptive. We systematically reviewed the literature on stress management interventions for adolescents and found there is evidence to support the effectiveness of interventions that aim to develop cognitive skills among adolescents; however, most studies had small samples and relied on different operational definitions of outcomes. Few included biological indicators of stress. Further study is needed to develop interventions to enhance adolescents’ capacity to manage stress.
There is ample evidence that adolescents experience stress as they develop and respond to myriad stimuli from their environments. The second decade of life is the most rapid developmental period after infancy, and during this time of multiple transitions, adolescents experience stress in several domains of their lives. The physical development that characterizes adolescence often creates anxiety and feelings of stress (Ruuska, Kaltiala-Heino, Koivisto, & Rantanen, 2003, p. 218). Adolescents are particularly vulnerable to stress-related depression, owing to their developing mesocorticolimbic dopamine systems (Andersen & Teicher, 2008). Similarly, emotional and social transitions associated with the shift in parent–child relationships, new school environments, and the realignment of the adolescent with their peers’ larger social systems have been shown to be associated with stress and anxiety in adolescents (Grills-Taquechel, Norton, & Ollendick, 2010; Raudino, Fergusson, & Horwood, 2013; Sontag & Graber, 2010). In addition to these expected developmental stressors, some adolescents experience chronic stress (e.g., poverty, disrupted
Address correspondence to Lynn Rew, University of Texas at Austin, School of Nursing, 1700 Red River, Austin, Texas 78701, USA. E-mail: [email protected]
family and home environments) that can lead to a number of adverse health outcomes. For example, the number of adolescents aged 12–17 years living in low-income poor families is rising: in 2011, 41% were from low-income families, while 19% were from poor families (Addy, Engelhardt, & Skinner, 2013). Evans and Kim (2012) found that adolescents 17 years of age who spend longer periods of their childhood (birth to 9 years) living in poverty had higher levels of chronic physiologic stress. Across this range of stressful experiences, however, we know very little about interventions that successfully reduce or prevent deleterious symptoms of stress in adolescents. Thus, the purpose of this paper is to report the findings from a systematic review of the literature on interventions to reduce stress in adolescents aged 10–19 years. This age range was selected because it reflects the definition of adolescence provided by the World Health Organization (2013). This definition is often cited in the literature pertaining to adolescence and has a global understanding.
BACKGROUND The concept of stress was first introduced into health-related literature in 1978, when Hans Selye coined the terms stressor and stress to denote cause and effect of what he had described as the ‘General Adaptation Syndrome (GAS)’. Selye noted that the use of the word in engineering ‘to denote the effects of a force acting against resistance’ were comparable with the human responses he had observed and recorded as the GAS (Selye, 1978, p. 45). Lazarus and Folkman (1984) later described stress as a transaction between a stimulus in the environment and a person. These theorists focused on cognitive appraisal of the stimulus as perceived harm or loss, threat, or challenge and the response of the person as the coping process. In 1999, Lazarus published a synthesis of stress and emotion, in which he wrote, ‘The three concepts, stress, emotion, and coping, belong together and form a conceptual unit, with emotion being the superordinate concept because it includes stress and coping’ (p. 37).
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In contrast to approaching the effects of stress as pathogenic, or causing a disease, Antonovsky (1979) introduced the term salutogenesis to the literature on stress, by which he meant those factors that enabled people to thrive in the face of numerous and enormous threats. One of the central tenets of Antonovsky’s conceptualization of stress is the concept of sense of coherence. Sense of coherence refers to an individual’s ‘enduring though dynamic feeling of confidence that one’s internal and external environments are predictable and that there is a high probability that things will work out as well as can reasonably be expected’ (Antonovsky, 1979, p. 123). In recent years, stress has become more clearly understood in terms of ‘allostatic load’, the physiological dysregulation that occurs with chronic stress (Gallo, Jim´enez, Shivpuri, de los Monteros, & Mills, 2011). Allostatic load refers to the burden associated with cumulative experiences of stress as it changes the hypothalamic-pituitary-adrenal (HPA) axis. Such changes, or dysregulation, of the HPA system can have ‘powerful and enduring effects on the brain’ (Katz, Sprang, & Cooke, 2012, p. 471). Adverse childhood experiences, such as maltreatment and chronic stress have been shown to create long-lasting changes in endocrine, immune, and nervous systems, including underdevelopment of the prefrontal cortex (Danese & McEwen, 2012). Several stress reduction approaches have been developed for adults. Mindfulness-based studies, for example, have been shown to be effective in reducing stress in patients with cancer (Lengacher et al., 2012; Matchim, Armer, & Stewart, 2011) and in reducing depressive symptoms in persons with mental disorders (Barnhofer, Crane, Hargus, Amarasinghe, Winder, & Williams, 2009; Klainin-Yobas, Cho, & Creedy, 2012).
Sources of Stress in Adolescents Stressors in adolescents range from the stress of daily living (also known as hassles) to the development of post-traumatic stress disorder (PTSD) and complex traumatic stress reactions that can lead to significant emotional dysregulation and stressrelated diseases (Ford, 2011; Gerson & Rappaport, 2013). Daily hassles, such as school, family, and friends have been identified by adolescents as sources of stress (Wright, Creed, & Zimmer-Gembeck, 2010). School is frequently identified as a major source of stress for adolescents (LaRue & Herrman, 2008). In a study of 216 adolescents who took part in a longitudinal study, Rew, Tyler, Fredland, and Hannah (2012) found that the top four concerns of adolescents in high school were education, relationships, expectations, and future. Other things that these adolescents worried about included the economy, future careers, sexuality, and death. Finally, evidence suggests that perceived racial and ethnic discrimination is related to distress in youths of color (Fisher, Wallace, & Fenton, 2000).
Stress Outcomes Research has shown that stress in adolescence is related to health-risk behaviors, such as alcohol and other substance use (King, Molina, & Chassin, 2009; Wills, Sandy, Yaeger, Cleary, & Shinar, 2001), as well as smoking (Finkelstein, Kubzansky, & Goodman, 2006). A study of 451 adolescents, ages 13–17 years, with alcoholic parents and a matched control found that stressors were related to adolescents’ alcohol use and predicted short-term increases in use (King, Molina, & Chassin, 2009). Stress has also been associated with poor dietary habits in adolescents. For example, the Health and Behavior in Teenagers Study (HABITS), which sampled over 4,000 diverse students in public schools (mean age = 11.83 years), found that greater stress was related to eating more fatty foods and snack foods, and fewer fruits and vegetables (Cartwright, Wardle, Simon, Croker, & Jarvis, 2003). Previous studies of stress in adolescents included those that addressed coping with specific diseases, such as HIV/AIDS (Lewis & Brown, 2002; Sibinga, Stewart, Magyari, Welsh, Hutton, & Ellen, 2008), asthma (Murdock, Greene, Adams, Hartmann, Bittinger, & Will, 2010; Peeters, Boersma, & Koopman, 2008), and diabetes (Antal, Wysocki, Canas, Taylor, & Edney-White, 2010; McCarty et al., 2010). Other studies addressed stress and coping in more general terms, such as exploring the effects of art on reducing stress in hospitalized children and adolescents (Eisen, Ulrich, Shepley, Varni, & Sherman, 2008). METHODS This systematic review of the literature was guided by the 27 items on the checklist of the Preferred Reporting Items for Systematic reviews and Meta-Analyses, known as PRISMA (Liberati et al., 2009). The purpose of PRISMA is to ensure completeness and transparency in the reporting of literature reviews. Research Questions The review of literature was designed to answer the following research questions: 1. What types of research design were used in studies of stress management interventions for adolescents? 2. What were the characteristics (i.e., content, setting/method, length) of stress reduction interventions for adolescents? 3. What were the stress-related outcomes of stress reduction interventions reported for adolescents? The retrieval and inclusion of information reported in this systematic literature review was guided by the four phases of PRISMA: ‘identification, screening, eligibility, and included’ (Liberati et al., 2009, p. 68).
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Identification Search engines used to identify the relevant literature were Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Education Resources Information Center (ERIC), MEDLINE, PsychArticles, PsycInfo, PUBMED, and Cochrane. Two searches were conducted with each search engine using the following terms: (1) Child + stress + stress reduction and (2) Adolescent + stress + stress reduction. After the initial reviews were completed, we performed a hand search of the references in the articles we found through our databases. We reviewed these additional references and included all eligible articles in this review. Screening All ‘hits’ were screened for duplicates and whether or not they met the inclusion/exclusion criteria. Those that did not meet the eligibility and inclusion criteria or were duplicates, were removed from the final dataset. Eligibility A final set of 17 articles was deemed eligible for the systematic review. The same inclusion/exclusion criteria were used to determine eligibility of articles that surfaced during the hand search. The set of eligible articles were then included in the systematic review. Inclusion criteria were that the article was peerreviewed, written in English, published between 1988 and 2013, addressed an intervention to reduce stress in adolescents (ages 10–19), and included a measure of stress as an outcome. Exclusion criteria included books, dissertations, reports, or clinical guidelines. Procedure After identifying, screening, and determining eligibility of the lists of articles, we conducted hand searches of all articles that were to be included in the report. This then determined the final number of articles for review. We then extracted data from the selected articles using a spreadsheet with headings to match our research questions; each article was read independently by at least two of the authors to extract the data. Data were then analyzed and synthesized to comprise this report. FINDINGS Figure 1 shows the summary of articles included in each phase of data identification, screening, eligibility, and inclusion. The search using the terms child + stress + stress reduction yielded 259 articles and the search using the terms adolescent + stress + stress reduction yielded 158 articles, for a total of 417. After removing duplicates, a total of 326 articles remained. Abstracts of the 326 articles were then screened for eligibility and inclusion in the penultimate sample of 14 published articles. Three more articles were retrieved
Total citations (n = 417) Duplicates removed (n = 91)
Abstracts reviewed (n = 326) Excluded by title or Abstract contents (n = 312)
Articles reviewed (n = 14)
Additional articles from hand searches (n = 3)
Final articles reviewed (n = 17) FIGURE 1 Flowchart of literature searches on stress reduction interventions for adolescents.
from our hand search of references for a total final sample of 17 articles that were included in the review. Study Designs Nine of the studies (60%) used randomized designs with the unit of randomization being at the individual level for five of the studies (Barnes, Treiber, & Davis, 2001; Davey & Neff, 2001; Hains & Szyjakowski, 1990; Weigensberg et al., 2009; Wright, Gregoski, Tingen, Barnes, & Treiber, 2011) and the group level (e.g., school, classroom) for four studies (Barnes, Treiber, & Johnson, 2004; Jellesma & Cornelis, 2012; White, 2012; Yahav & Cohen, 2008). Those that randomized at the group level had two of five schools or classrooms in the study to randomly assign to intervention or control conditions, which was not adequate to ensure confounders would be equally distributed across the sample (Barnes et al., 2004; Jellesma & Cornelis, 2012; White, 2012; Yahav & Cohen, 2008). Furthermore, random assignment at the classroom level introduced the potential for contamination of control groups housed in the same school as the intervention groups (Yahav & Cohen, 2008). Three of the four studies that randomized at the group level reported a data analysis plan that accounted for clustering (Barnes et al., 2004; Jellesma & Cornelis, 2012; Yahav & Cohen, 2008). Seven studies employed quasi-experimental designs, five of which had intervention and control/comparison groups (Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; Norlander, Moas, & Archer, 2005; Rauhala, Alho, Hanninen, &
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Helin, 1990), whereas two used single-group pre/post-test designs (Grosswald, Stixrud, Travis, & Bateh, 2008; Tan & Martin, 2012). Finally, one study employed a mixed methods design (Sibinga, Kerrigan, Stewart, Johnson, Magyari, & Ellen, 2011). Sample Sizes and Attrition Across studies, baseline sample sizes ranged from 10 to 255, with four studies having sample sizes smaller than 25 (Grosswald et al., 2008; Hains & Szyjakowski, 1990; Tan & Martin, 2012; Weigensberg et al., 2009); six studies having sample sizes between 25 and 100 (Barnes et al., 2001; Davey & Neff, 2001; Jellesma & Cornelis, 2012; Norlander et al., 2005; Rauhala et al., 1990; Sibinga et al., 2011), and seven studies having sample sizes larger than 100 (Barnes et al., 2004; Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; White, 2012; Wright et al., 2011; Yahav & Cohen, 2008). Only one study reported doing a power analysis (White, 2012). Most studies did not address attrition rates or amount of missing data between baseline and final measures; those that did, reported attrition rates between 0% (Jellesma & Cornelis, 2012; Weigensberg et al., 2009) and 36% (Barnes et al., 2004) and up to 42% missing data (Sibinga et al., 2011). It was not always clear whether authors were reporting attrition rates or amounts of useable data (i.e., missing data from youth who did not drop out of the study). Sample Demographics A diverse range of youth was included across studies. Average age ranged from 9.9 years, which we rounded up to 10 to meet our inclusion criteria (White, 2012) to 17.4 (Broderick & Metz, 2009), and studies included youth anywhere from 6 years old (Davey & Neff, 2001) to 21 years old (Sibinga et al., 2011). Most study samples were relatively evenly split between males and females (n = 11). Some studies focused exclusively on males (Hains & Szyjakowski, 1990; Rauhala et al., 1990) or females (Broderick & Metz, 2009; White, 2012). Two others had samples that were over 75% male (Grosswald et al., 2008) or female (Sibinga et al., 2011). Four studies were conducted outside of the USA, specifically the Netherlands (Jellesma & Cornelis, 2012), Sweden (Norlander et al., 2005), Australia (Tan & Martin, 2012), and Israel (Yahav & Cohen, 2008). Of the 13 studies conducted in the USA, over half of these (n = 8) had samples that were predominantly (≥60%) youth of color (Barnes et al., 2004; Barnes et al., 2001; Davey & Neff, 2001; Elder et al., 2011; Grosswald et al., 2008; Sibinga et al., 2011; Weigensberg et al., 2009; Wright, 2011). In studies based in the USA, the diversity of samples is a strength in terms of focusing on populations that may face higher levels of stress (e.g., due to discrimination, poverty), but also may limit generalizability to the broader population of US youth. Finally, many studies focused on general samples of school-based youth, while others focused on specific populations of youth for whom stress management is particularly crucial, including youth at risk for high blood pressure
(Barnes et al., 2001; Wright et al., 2011), living with their families in homeless shelters (Davey & Neff, 2001), living with ADHD (Grosswald et al., 2008), residing in rehabilitation centers (Rauhala et al., 1990), and living with HIV (Sibinga et al., 2011). Intervention Characteristics Content The content of the stress reduction interventions reviewed can be placed into four broad categories: (1) mindfulness/awareness; (2) Transcendental meditation (TM); (3) relaxation exercises; and (4) life skills training. Mindfulness/awareness techniques emphasize non-judgmental attention to the present moment (i.e., ‘mindfulness’) and were the most frequent techniques reported (n = 8; Broderick & Metz, 2009; Davey & Neff, 2001; Jellesma & Cornelis, 2012; Sibinga et al., 2011; Tan & Martin, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Several studies used a modified version of the standard mindfulness-based stress-reduction program (Kabat-Zinn, 1982) that had been tailored to the developmental and functional needs of the adolescent populations with whom they were working (Broderick & Metz, 2009; Sibinga et al., 2011; Tan & Martin, 2012). Another frequently utilized mindfulness strategy was the use of awareness exercise activities, such as breathing and yoga postures (Davey & Neff, 2001; Jellesma & Cornelis, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Four studies reported using the standard TM format (Barnes et al., 2001; Barnes et al., 2004; Elder et al., 2011; Grosswald et al., 2008). TMTM is a registered, trademarked technique of the Maharishi Foundation USA and fundamentally differs from mindfulness-based techniques in that TM encourages the practitioner to do nothing to control their mind or direct their attention in any particular direction. One of the interventions tested by Wright and colleagues (2011) combined components of TM and mindfulness-based techniques by utilizing the structure of TM (i.e., twice daily 10 min sessions) but instructed their participants to focus on the movement of the diaphragm (i.e., awareness). Relaxation exercises in the form of stretching, progressive relaxation, visualization-based relaxation, and muscle contraction and release were present in six of the reviewed interventions (Davey & Neff, 2001; Jellesma & Cornelis, 2012; Norlander et al., 2005; Rauhala et al., 1990; Weigensberg et al., 2009; Yahav & Cohen, 2008). The final category of intervention content, termed ‘life skills training’ by Wright and colleagues (2011), provided didactic content related to stress and coping. These interventions focused on teaching participants to identify sources of stress, evaluate their emotional response to identified stressors, and employ strategies to minimize the effect of stressors (e.g., problem-solving, conflict resolution, talking about their feelings, and anger management) (Hains & Szyjakowski, 1990; Wright et al., 2011; Yahav & Cohen, 2008). The majority of interventions (n = 10) included some form of home practice/homework for participants to complete between
INTERVENTIONS TO REDUCE STRESS IN ADOLESCENCE
intervention sessions (Barnes et al., 2001; Barnes et al., 2004; Broderick & Metz, 2009; Davey & Neff, 2001; Elder et al., 2011; Grosswald et al., 2008; Tan & Martin, 2012; Weigensberg et al., 2009; White, 2012; Wright et al., 2011). Several unique intervention components were also identified within the reviewed studies. Rauhala and colleagues (1990) were distinctive in their use of aerobic physical activity and sauna sessions, and Yahav and Cohen (2008) incorporated biofeedback technology within their life skills training and relaxation intervention. Settings and Method of Delivery The setting of intervention delivery was closely linked with location and method of subject recruitment. For example, Davey and Neff (2001) recruited participants from two family-shelter facilities, and the group intervention was conducted at these shelters. The majority of studies (n = 12) delivered group interventions in classroom-based settings (Barnes et al., 2001; Barnes et al., 2004; Broderick & Metz, 2009; DeWolfe & Saunders, 1995; Elder et al., 2011; Grosswald et al., 2008; Jellesma & Cornelis, 2012; Norlander et al., 2005; Tan & Martin, 2012; White, 2012; Wright et al., 2011; Yahav & Cohen, 2008). Of these classroom-based studies, only one (White, 2012) did not deliver the intervention within the standard school day; group sessions were conducted immediately after the school day had ended. The setting of intervention delivery was not specified in five of the reviewed articles. Rauhala et al. (1990) conducted their intervention with adolescent boys residing in a community rehabilitation home for young offenders, and the setting of delivery is implied as within this setting. Sibinga et al. (2011) and Tan and Martin (2012) utilized clinic-based recruitment strategies, but the setting of intervention delivery was not specified for their group interventions. Hains and Szyjakowski (1990) conducted both group and individual intervention sessions with participants from an all-male college-preparatory parochial school, but the setting of delivery was not specified. Weigensberg et al. (2009) did not state where they conducted their intervention consisting of individual weekly sessions. Intervention Length Total length of interventions ranged from 1 month (4 weeks) (Davey & Neff, 2001; Norlander et al., 2005; Weigensberg et al., 2009) to 4 months (16 weeks) (Barnes et al., 2004; Elder et al., 2011; Rauhala et al., 1990). The intervention length most frequently reported (n = 4) was 2 months (Barnes et al., 2001; DeWolfe & Saunders, 1995; White, 2012; Yahav & Cohen, 2008). Two months was also the median of intervention length. Hains and Szyjakowski (1990) were the only researchers who failed to report intervention duration. The intervention consisted of three phases, each of which contained one group session (1-h each) and two individual sessions (30–40 min each, last individual session
