A Meta-Analysis of Interventions to Reduce Loneliness

“loneliness, intervention, meta-analysis, social cognition The formation of meaningful social connections is an integral part of human nature (Baumeister & Leary, 1995; Cacioppo & Patrick, 2008).”

“The revised UCLA Loneliness Scale: Concurrent and discriminant validity evidence.”

“…these features have also been found to be highly correlated, and their antecedents and consequences have been found to be sufficiently overlapping that loneliness is generally conceptualized and measured as a unidimensional construct (Hawkley et al., 2005; Russell, 1996; Russell et al., 1980).”

“Although various studies have provided evidence that the experience of loneliness can be partitioned into separable dimensions, including social and emotional loneliness (Weiss, 1973), these features have also been found to be highly correlated, and their antecedents and consequences have been found to be sufficiently…”

“Kraut et al. (1998): The sample was 93 families with both teens and adults; the mean age was not calculated because of the heterogeneous nature of the sample.”

“Therefore, these studies begin to fulfill the criterion that the intervention be replicated by independent research groups to be considered empirically supported (Chambless & Hollon, 1998).”

“Loneliness impairs executive functioning in part because it triggers implicit hypervigilance for social threats (Cacioppo & Hawkley, 2009).”

“Interventions to reduce loneliness have been developed because the chronic form of loneliness is highly aversive (Peplau & Perlman, 1982; Weiss, 1973), is a significant risk factor for mental and physical health problems (Danese et al., 2009; Hawkley & Cacioppo, 2007), and adversely affects others…”

“Compared to nonlonely individuals, lonely people are also more likely to suffer from cognitive decline (Tilvis et al., 2004) and progression of Alzheimer’s disease (R. S. Wilson et al., 2007).”

“In addition, longitudinal analysis reveals that adults who were socially isolated as children are more likely to have risk factors for cardiovascular disease, including overweight, high blood pressure, high total cholesterol, low high-density lipoprotein cholesterol, high glycated hemoglobin, and low maximum oxygen co…”

“On the other hand, despite not returning to the level of healthy, community-living adults, the small reduction in loneliness score is consistent with the notion of “improved but not recovered” (Jacobson et al., 1999).”

“The revised UCLA Loneliness Scale: Concurrent and discriminant validity evidence.”

“, 2002; Hawkley, Preacher, & Cacioppo, 2010), increased hypothalamic pituitary adrenocortical activity (Adam, Hawkley, Kudielka, & Cacioppo, 2006), diminished immunity (Kiecolt-Glaser et al., 1984; Pressman et al., 2005), underexpression of genes bearing anti-inflammatory glucocorticoid response elements (Cole et al.”

“…2006), diminished immunity (Kiecolt-Glaser et al., 1984; Pressman et al., 2005), underexpression of genes bearing anti-inflammatory glucocorticoid response elements (Cole et al., 2007), and abnormal ratios of circulating white blood cells (e.g., neutrophils, lymphocytes, and monocytes; Cole, 2008).”

“In a study of kindergarteners and first graders, 12% reported feeling lonely at school (Cassidy & Asher, 1992).”

“Factors negatively associated with loneliness included social network size, satisfaction with social network, and having a spousal confidant (Hawkley et al., 2008).”

“…hypothalamic pituitary adrenocortical activity (Adam, Hawkley, Kudielka, & Cacioppo, 2006), diminished immunity (Kiecolt-Glaser et al., 1984; Pressman et al., 2005), underexpression of genes bearing anti-inflammatory glucocorticoid response elements (Cole et al., 2007), and abnormal ratios…”

“Compared to nonlonely individuals, lonely people are also more likely to suffer from cognitive decline (Tilvis et al., 2004) and progression of Alzheimer’s disease (R. S. Wilson et al., 2007).”

“Banks et al. (2008) and Winningham and Pike (2007) did not report the gender composition of their samples.”

“Hopps, Pepin, and Boisvert (2003) and Shapira, Barak, and Gal (2007) reported one-way ANOVA F statistics; Morrow-Howell et al. (1998), White et al. (2002), and Williams et al. (2004) reported t test statistics; and Rosen and Rosen (1982) reported c2 statistics.”

“Although some of the programs in this review showed benefit, Findlay (2003) noted that many were flawed by weak study design.”

“Of these, 3 used a singlegroup pre-post design (McAuley et al., 2000; Stewart et al., 2001; Stewart et al., 2009), 3 used a nonrandomized group comparison design (Allen-Kosal, 2008; Martina & Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria,…”

“For studies that reported sample age only as a threshold (e.g., 75 years or older), the threshold age was used as the mean age of the sample (Banks & Banks, 2002).”

“Hopps, Pepin, and Boisvert (2003) and Shapira, Barak, and Gal (2007) reported one-way ANOVA F statistics; Morrow-Howell et al. (1998), White et al. (2002), and Williams et al. (2004) reported t test statistics; and Rosen and Rosen (1982) reported c2 statistics.”

“, 2009), 3 used a nonrandomized group comparison design (Allen-Kosal, 2008; Martina & Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria, 2006; Coleman et al., 2005; Conoley & Garber, 1985; E. O. Cox et al., 2007; Fukui, Koike, Ooba, & Uchitomi, 2003; K. Heller et…”

“Although this typology does not perfectly match that of Rook (1984) or McWhirter (1990b), most of the studies addressed social skills, social support, opportunities for social interaction, or social cognition.”

“In the other three reviews, this classification was implicit, although not all reviews included studies that addressed impaired social cognition (Cattan et al., 2005; Cattan & White, 1998; Findlay, 2003).”

“According to the 2002 Health and Retirement Survey, 19.3% of U.S. adults older than age 65 reported feeling lonely for much of the previous week (Theeke, 2009).”

“Rook (1984) acknowledged that many of the studies in her review were not successful or lacked experimental rigor but indicated that interventions that focused on social skills, social support, opportunities for social interaction, and social cognition held promise for reducing loneliness.”

“Four of the studies reported baseline differences in loneliness between the treatment and control groups (Cohen et al., 2006; Hartke & King, 2003; Martina & Stevens, 2006; White et al., 1999).”

“In addition, socially isolated animals demonstrate less dendritic arborization in the hippocampus and prefrontal cortex (Silva-Gomez, Rojas, Juarez, & Flores, 2003) as well as decreased production of brainderived neurotropic factors (Barrientos et al., 2003).”

“Although few studies have evaluated this approach, one study found mutual help groups reduced psychiatric symptoms, hospitalizations, and social isolation among the mentally ill (Galanter, 1988). According to Perese and Wolf (2005), one way to increase opportunities for social interaction is befriending, which “aims t…”

“Although 12 studies originally failed to meet this criterion (Andersson, 1985; Brown, Allen, Dwozan, Mercer, & Warren, 2004; Clarke, Clarke, & Jagger, 1992; Evans & Jaureguy, 1982; Evans, Smith, Werkhoven, Fox, & Pritzl, 1986; Jones et al., 1982; McLarnon & Kaloupek, 1988; Routasalo, Tilvis, Kautiainen, & Pitkala, 200…”

“Using procedures described by Borenstein et al. (2009), the influence of categorical moderator variables was assessed using subgroup analyses analogous to ANOVAs that partition the total effect size variance into variance within and between groups.”

“The final review examined 36 studies and focused on persons with severe mental illness, a population whose 224 Personality and Social Psychology Review 15(3) prevalence of loneliness is approximately twice that of the general population (Perese & Wolf, 2005).”

“McWhirter (1990b) referred to several CBT-based studies that succeeded in reducing loneliness (Anderson & Arnoult, 1985; Anderson et al., 1983; Young, 1982).”

“…Tilvis, Kautiainen, & Pitkala, 2009; Seepersad, 2005; Stewart, Reutter, Letourneau, & Makawarimba, 2009; van Kordelaar, Stevens, & Pleiter, 2004; van Rossum et al., 1993), attempts to recover quantitative data from the authors were successful in two cases (Evans et al., 1986; Seepersad, 2005).”

“McWhirter (1990b) referred to several CBT-based studies that succeeded in reducing loneliness (Anderson & Arnoult, 1985; Anderson et al., 1983; Young, 1982).”

“…2006), diminished immunity (Kiecolt-Glaser et al., 1984; Pressman et al., 2005), underexpression of genes bearing anti-inflammatory glucocorticoid response elements (Cole et al., 2007), and abnormal ratios of circulating white blood cells (e.g., neutrophils, lymphocytes, and monocytes; Cole, 2008).”

“…& Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria, 2006; Coleman et al., 2005; Conoley & Garber, 1985; E. O. Cox et al., 2007; Fukui, Koike, Ooba, & Uchitomi, 2003; K. Heller et al., 1991; Kremers et al., 2006; McWhirter & Horan, 1996).”

“Banks et al. (2008) and Winningham and Pike (2007) did not report the gender composition of their samples.”

“Of these, 3 used a singlegroup pre-post design (McAuley et al., 2000; Stewart et al., 2001; Stewart et al., 2009), 3 used a nonrandomized group comparison design (Allen-Kosal, 2008; Martina & Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria,…”

“This finding is somewhat disappointing as technology-based interventions have been helpful in managing other chronic diseases (Celler, Lovell, & Basilakis, 2003; Gaikwad & Warren, 2009).”

“However, simply bringing lonely people together may not result in new friendships because the thoughts and behaviors of lonely individuals make them less attractive to one another as relationship partners (Jerrome, 1983; Stevens, 2001).”

“…(Peplau, Miceli, & Morasch, 1982), tend to blame themselves for social failures (Anderson, Horowitz, & French, 1983), are more self-consciousness in social situations (Cheek & Busch, 1981), and adopt behaviors that increase, rather than decrease, their likelihood of rejection (Horowitz, 1983).”

“Among mice, social isolation reduces central anti-inflammatory responses and increases infarct size following induction of stroke (Karelina et al., 2009).”

“…Brannen, & Best, 2004) used in Yarnoz, Plazaola, and Etxeberria (2008); (c) 16-item Loneliness Scale (Asher, Hymel, & Renshaw, 1984) used in Bauminger (2007) and Christian and D’Auria (2006); (d) 24-item Loneliness Scale (Asher & Wheeler, 1985) used in Kolko, Loar, and Sturnick (1990) and…”

“One study (Stevens, Martina, & Westerhof, 2006) was excluded because it duplicated data and because more complete results were reported in Martina and Stevens (2006), which was already included as an eligible study.”

“Although few studies have evaluated this approach, one study found mutual help groups reduced psychiatric symptoms, hospitalizations, and social isolation among the mentally ill (Galanter, 1988).”

“Four of the studies reported baseline differences in loneliness between the treatment and control groups (Cohen et al., 2006; Hartke & King, 2003; Martina & Stevens, 2006; White et al., 1999).”

“Hill, Weinert, and Cudney (2006): The sample age ranged from 35 to 65 years old, with 92% older than 40 years old; the mean age was inferred to be 52 years old.”

“Seven studies were excluded because the interventions were directed at stress relief (Whitehouse et al., 1996), anxiety and/or depression (Mynatt, Wicks, & Bolden, 2008; Ransom et al., 2008), or health behaviors (de Craen, Gussekloo, Blauw, Willems, & Westendorp, 2006; Hedberg, Wikstrom-Frison, &…”

“Various factor analytic studies have provided some evidence that the experience of loneliness can be partitioned into separable dimensions (Hawkley, Browne, & Cacioppo, 2005; Knight, Chisholm, Nigel, & Godfrey, 1988; McWhirter, 1990a), but these factors have also been found to be highly correlated, and their anteceden…”

“Research indicates that loneliness is approximately 50% heritable and 50% environmental (Boomsma, Willemsen, Dolan, Hawkley, & Cacioppo, 2005; McGuire & Clifford, 2000).”

“…= 7.73, df = 3, p = .05), and the 4 social cognitive training interventions (Chiang et al., 2009; Conoley & Garber, 1985; McWhirter & Horan, 1996; Williams et al., 2004) yielded greater loneliness reduction (mean effect size = –0.598, p = .001) compared to the 12 interventions to enhance social…”

“Although the residents tended to stay in their rooms because of physical disability and fear of crime, the program increased social interaction in the lobbies and, over time, helped participants identify shared interests (Pilisuk & Minkler, 1980).”

“In Samarel, Tulman, and Fawcett (2002), the treatment included telephone support and group social support along with a mailed education kit; one control group received telephone support with mailed materials, and the other control group received only the mailed materials.”

“…effect sizes:9 One was a single-group pre-post design (Stewart et al., 2001), one was a nonrandomized group comparison design (Allen-Kosal, 2008), and four used a randomized group comparison design (Christian & D’Auria, 2006; Fukui et al., 2003; Heckman & Barcikowski, 2006; Kremers et al., 2006).”

“Two studies had interventions that were in effect continuously for a period of time and thus could not be quantified into sessions: Jessen, Cardiello, and Baun (1996), who placed a caged bird in participants’ rooms for 10 days; and Ollonqvist et al. (2008), who implemented an intervention that…”

“…for the bereaved (Vachon, Lyall, Rogers, Freedman-Letofsky, & Freeman, 1980), for the elderly whose personal networks had been disrupted by relocation (Kowalski, 1981), and for children whose parents had divorced (Wallerstein & Kelly, 1977) all demonstrated Masi et al. 223 loneliness reductions.”

“…effect sizes:9 One was a single-group pre-post design (Stewart et al., 2001), one was a nonrandomized group comparison design (Allen-Kosal, 2008), and four used a randomized group comparison design (Christian & D’Auria, 2006; Fukui et al., 2003; Heckman & Barcikowski, 2006; Kremers et al., 2006).”

“, 1996), anxiety and/or depression (Mynatt, Wicks, & Bolden, 2008; Ransom et al., 2008), or health behaviors (de Craen, Gussekloo, Blauw, Willems, & Westendorp, 2006; Hedberg, Wikstrom-Frison, & Janlert, 1998; Hopman-Rock & Westhoff, 2002; Soholt Lupton, Fonnebo, Sogaard, & Fylkesnes, 2005).”

“…Hymel, & Renshaw, 1984) used in Bauminger (2007) and Christian and D’Auria (2006); (d) 24-item Loneliness Scale (Asher & Wheeler, 1985) used in Kolko, Loar, and Sturnick (1990) and Allen-Kosal (2008); (e) 7-item loneliness scale (Paloutzian & Ellison, 1982) used in K. Heller, Thompson,…”

“Conoley and Garber (1985) administered cognitive reframing as the main intervention.”

“To interpret this effect size in familiar units, the 6 randomized studies that used the 20-item UCLA Loneliness Scale and reported loneliness means and standard deviations were further evaluated (Chiang et al., 2009; Coleman et al., 2005; Conoley & Garber, 1985; Hill, Weinert, & Cudney, 2006; Jessen, Cardiello, & Baun…”

“Hopps, Pepin, and Boisvert (2003) and Shapira, Barak, and Gal (2007) reported one-way ANOVA F statistics; Morrow-Howell et al. (1998), White et al. (2002), and Williams et al. (2004) reported t test statistics; and Rosen and Rosen (1982) reported c2 statistics.”

“…effect sizes:9 One was a single-group pre-post design (Stewart et al., 2001), one was a nonrandomized group comparison design (Allen-Kosal, 2008), and four used a randomized group comparison design (Christian & D’Auria, 2006; Fukui et al., 2003; Heckman & Barcikowski, 2006; Kremers et al., 2006).”

“The author noted that although social skills training was initially developed to reduce anxiety and shyness, it has been successfully adapted to treat loneliness (Twentyman & Zimering, 1979).”

“One study (Hu, 2009) examined the effect of an intervention on an induced state of loneliness and was excluded from the analysis because induced loneliness is not comparable to the loneliness targeted in other included studies.”

“…of the unpredictable nature of homeless youth; Petryshen, Hawkins, and Fronchak (2001), because participants were offered a choice from about 200 group activities; and Morrow-Howell, Becker-Kemppainen, and Lee (1998), because of the different level of needs and suicide risks of their sample.”

“…Tilvis, Kautiainen, & Pitkala, 2009; Seepersad, 2005; Stewart, Reutter, Letourneau, & Makawarimba, 2009; van Kordelaar, Stevens, & Pleiter, 2004; van Rossum et al., 1993), attempts to recover quantitative data from the authors were successful in two cases (Evans et al., 1986; Seepersad, 2005).”

“Four studies did not provide information on intervention frequency: Marshall et al. (1996) and three studies listed in Fokkema (unpublished): (a) buddy care for homosexuals, (b) elderly support home visits, and (c) good company in a big home.”

“…for a period of time and thus could not be quantified into sessions: Jessen, Cardiello, and Baun (1996), who placed a caged bird in participants’ rooms for 10 days; and Ollonqvist et al. (2008), who implemented an intervention that included three separate inpatient periods over 8 months.”

“Of these, 3 used a singlegroup pre-post design (McAuley et al., 2000; Stewart et al., 2001; Stewart et al., 2009), 3 used a nonrandomized group comparison design (Allen-Kosal, 2008; Martina & Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria,…”

“…Mercer, & Warren, 2004; Clarke, Clarke, & Jagger, 1992; Evans & Jaureguy, 1982; Evans, Smith, Werkhoven, Fox, & Pritzl, 1986; Jones et al., 1982; McLarnon & Kaloupek, 1988; Routasalo, Tilvis, Kautiainen, & Pitkala, 2009; Seepersad, 2005; Stewart, Reutter, Letourneau, & Makawarimba, 2009; van…”

“…et al., 1996), anxiety and/or depression (Mynatt, Wicks, & Bolden, 2008; Ransom et al., 2008), or health behaviors (de Craen, Gussekloo, Blauw, Willems, & Westendorp, 2006; Hedberg, Wikstrom-Frison, & Janlert, 1998; Hopman-Rock & Westhoff, 2002; Soholt Lupton, Fonnebo, Sogaard, & Fylkesnes, 2005).”

“According to Perese and Wolf (2005), one way to increase opportunities for social interaction is befriending, which “aims to develop a relationship between individuals that is distinct from professional/client relationships” (A. D. Cox, 1993, p. 9).”

“…12 studies originally failed to meet this criterion (Andersson, 1985; Brown, Allen, Dwozan, Mercer, & Warren, 2004; Clarke, Clarke, & Jagger, 1992; Evans & Jaureguy, 1982; Evans, Smith, Werkhoven, Fox, & Pritzl, 1986; Jones et al., 1982; McLarnon & Kaloupek, 1988; Routasalo, Tilvis, Kautiainen, &…”

“…and Alexander (2001); (b) 15-item short version of the Social and Emotional Loneliness Scale for Adults (DiTommaso, Brannen, & Best, 2004) used in Yarnoz, Plazaola, and Etxeberria (2008); (c) 16-item Loneliness Scale (Asher, Hymel, & Renshaw, 1984) used in Bauminger (2007) and Christian and…”

“Sorenson (2003) was therefore included in the subsequent moderator analyses.”

“…types was significant (Qb = 7.73, df = 3, p = .05), and the 4 social cognitive training interventions (Chiang et al., 2009; Conoley & Garber, 1985; McWhirter & Horan, 1996; Williams et al., 2004) yielded greater loneliness reduction (mean effect size = –0.598, p = .001) compared to the 12…”

“A sizable literature documents the benefits of owning “real” pets (Keil, 1988), so the real dog intervention was included as the primary intervention.”

“…that varied among participants: Stewart, Reutter, Letourneau, and Makawarimba (2009), because of the unpredictable nature of homeless youth; Petryshen, Hawkins, and Fronchak (2001), because participants were offered a choice from about 200 group activities; and Morrow-Howell,…”

“…Hobart, Jang, and Seo (2007); (g) Frequency of loneliness (Older Americans Resources and Services Social Resource Rating Scale) used in Morrow-Howell et al. (1998); and (h) a single question asking the participants if they feel lonely used in Rosen and Rosen (1982) and Ollonqvist et al. (2008).”

“Finally, deficits in social cognition were addressed through selfhelp groups, which attempted to change thinking from negative and fearful to positive and self-supportive (Murray, 1996).”

“Among interventions that enhanced social support, professionally initiated interventions for the bereaved (Vachon, Lyall, Rogers, Freedman-Letofsky, & Freeman, 1980), for the elderly whose personal networks had been disrupted by relocation (Kowalski, 1981), and for children whose parents had divorced (Wallerstein & Ke…”

“…& Stevens, 2006), and 9 used a randomized group comparison design (Chiang et al., 2009; Christian & D’Auria, 2006; Coleman et al., 2005; Conoley & Garber, 1985; E. O. Cox et al., 2007; Fukui, Koike, Ooba, & Uchitomi, 2003; K. Heller et al., 1991; Kremers et al., 2006; McWhirter & Horan, 1996).”

“One reason is that single-group pre-post studies are vulnerable to regression toward the mean, in which individuals who have high scores on a loneliness measure on one occasion are likely to score less extremely on a second occasion even if no intervention had occurred (Weeks, 2007).”

“However, simply bringing lonely people together may not result in new friendships because the thoughts and behaviors of lonely individuals make them less attractive to one another as relationship partners (Jerrome, 1983; Stevens, 2001).”

“Addressing negative thoughts about social encounters (eg, self-blame, self-devaluation) may also be effective.(30,94) During periods of prolonged social isolation, digital technology that provides evidencebased interventions to help young people to reappraise their thoughts and to change their behavior within the conf…”

“Psychological approaches, such as Cognitive Behavioural Therapy and Mindfulness, have also been used to help people change their thinking about social relationships: some promising results have been reported, especially with older adult populations [77].”

“But, as noted above, a large number of contacts is not equivalent to high quality relationships (Masi et al., 2011).”

“Increasing opportunities for social interaction Within the literature on loneliness, there is the argument that increasing social contact and opportunities for social reconnection could reduce loneliness (Qualter, 2003), but reviews (S. Cacioppo, 2015; Masi et al., 2011) provide strong empirical evidence that there ar…”