Religious attendance after elevated depressive symptoms: is selection bias at work?

Introduction

Attendance at religious services is usually reported to be inversely related to depression (Baetz et al., 2004; Balbuena, Baetz & Bowen, 2013; Hayward et al., 2012; Maselko, Gilman & Buka, 2009). However, as with many findings in the literature on religion and depression, the results have not been consistent, with other studies reporting a null (Ellison & Flannelly, 2009; Miller et al., 2012; Schnittker, 2001) or curvilinear relationship of attendance and depression (Taylor, Chatters & Nguyen, 2013). This inconsistency has been due in part to the predominance of cross-sectional designs, which cannot establish causation. We are aware of only three longitudinal studies examining the relation of depression to subsequent religious attendance. Recently, it was reported (Maselko et al., 2012) that women having an onset of depression prior to age 18 were more likely to stop attending religious services as adults compared to those with adult-onset MDE and those with no lifetime MDE. Similarly, a longitudinal study (Horowitz & Garber, 2003) reported that depressive episodes in grades 7–11 predicted lower levels of religious attendance in grade 12. The latter result is ambiguous because religious attendance in grade 6 also predicted lower odds of depression in grades 7–12, although the effect was just shy of statistical significance. Miller and colleagues (2002) followed a cohort of 146 individuals who had an MDE in childhood together with a control group of 123 who had no psychiatric disorder over 11 years. At follow-up, the rates of religious attendance between groups did not differ by childhood depression status. It is noteworthy that these studies covered the adolescence-to-adult transition period. Late adolescence is generally a time of profound change. The quest to establish one’s identity and career (Arnett, 2000) and experimentation with cohabitation, drugs, and alcohol (Benda & Corwyn, 1997; Thornton, Axinn & Hill, 1992; Uecker, Regnerus & Vaaler, 2007) could precipitate internal conflicts with religious doctrine, leading to declines in religious attendance. In short, the developmental processes occurring during adolescence confounds the relation of depression with religious attendance, in either causal direction.

Selection effects might work in two ways to confound the relation of depression with subsequent religious attendance. First, depressed individuals may withdraw from public worship as part of the overall social disengagement that occurs in depression (Maselko et al., 2012). Secondly, churchgoers might be less susceptible to depression. A meta-analysis of 94 studies reported a positive correlation of agreeableness, conscientiousness, and sociability with religious social investment (Lodi-Smith & Roberts, 2007). In summary, theory suggests that depressed individuals select themselves out of the churchgoing demographic while healthy ones select themselves into it. These selection effects, if operative, would likely overestimate the protective value of religion for mental health.

The protective value of religiosity does have empirical support. Coping with adversity through religion is well-documented in the literature (Pargament, 1997). “Turning to God or religion” as a coping strategy has been reported in cancer patients (Bussing, Ostermann & Koenig, 2007), newly bereaved individuals (Brown et al., 2004), and new immigrants (Connor, 2009). A study comparing religiosity and spirituality before and after HIV patients were informed of the diagnosis (Ironson, Stuetzle & Fletcher, 2006) reported that religiosity (including attendance) increased after the diagnosis became known. Furthermore, increased religiosity was associated with greater CD4 helper cells in the blood, indicating slower HIV progression (Ironson, Stuetzle & Fletcher, 2006). A US longitudinal study reported that depressed individuals were more likely to seek religious consolation—defined as searching for meaning in problems and difficulties (Ferraro & Kelley-Moore, 2000). Importantly, even those with no initial religious affiliation sought religious consolation after depression. This finding seems to support the “no atheists in foxholes” aphorism. However, adversity or trauma can also cause individuals to turn away from God or religion (Chen & Koenig, 2006; Fontana & Rosenheck, 2004). We are not aware of longitudinal studies reporting changes to religious attendance per se (vis-a-vis religiosity broadly speaking) after a depressive episode aside from the three studies in adolescence (Horowitz & Garber, 2003; Maselko et al., 2012; Miller et al., 2002) already mentioned.

In this paper, our main objective was to study whether elevated depressive symptoms introduce selection bias in a longitudinal follow-up of religious attendance. Our research questions were as follows. First, do religious attenders who develop elevated depressive symptoms subsequently decrease their attendance level? Second, do non-attenders who develop elevated symptoms begin to attend services?

Materials and Methods

Sample

The data is from the Longitudinal Internet Studies for the Social Sciences (LISS) panel, a random sample of adults living in the Netherlands (Scherpenzeel, 2011). The panel of almost 8,000 individuals was drawn from the Dutch-speaking population based on a list of addresses provided by Statistics Netherlands. The recruitment strategy is described in more detail elsewhere (Scherpenzeel, 2011). LISS is a continuing study in which participants complete online questionnaires monthly on topics including family, economic situation, health, and religion. Each LISS participant has a unique member ID, so it is possible to combine their responses across different survey modules and from one wave to another. For the purpose of our study, we merged the religion (n = 7, 418) and mental health (n = 1, 804) modules, narrowing our sample to those who responded to both surveys (n = 1, 718) (see Fig. 1A). Waves of religion and depression assessments were not simultaneous, so hereafter, use the notations R_i and D_i to refer to religion and depression waves, respectively (see Fig. 1B). Our research question requires the following temporal sequence: R₁ → D₂ to D₄ → R₂. By comparing attendance level at R₂ with R₁, we can test whether depression predicts a relative decrease at R₂. This design requirement forced us to exclude those individuals (n = 41) who had a different sequence of assessments:

D₁ → D₂ → R₁ → D₂ to D₄ since for these individuals, one cannot compare attendance levels before and after depression. Our effective sample size was 1,673.

In the sample, 887 individuals did not attend services and 786 attended services at R₁. (Explained in Measures section below.) The characteristics of these groups are described in Table 1. After baseline assessment, D₁, depression was assessed during a seven-month span from March to September 2008 while attendance was assessed another four times in addition to R1, and these assessments occurred on each January from 2009 to 2012. Our main analytic strategy was to compare the proportion of individuals that changed their attendance level, stratified by baseline attendance. The change in attendance level was indexed to R₁ attendance since there were no further depression assessments after September 2008.

Table 1:

Comparison of attenders and non-attenders.

Characteristics of Dutch individuals who responded to mental health (Wave 1) and religious attendance (Wave 1–Jan 2008) of the Longitudinal Internet Studies for the Social Sciences (LISS), Netherlands (n = 1, 673).

	Service attenders at R1	Non-attenders of service at R1	p of the difference
n	786	887
Mean age (sd)	49.60 (18.22)	45.90 (17.21)	<.001
Civil status
Unmarried	323 (41)	443 (50)	<.001
Married	463 (59)	444 (50)
Monthly income
Low income (0–500 € per month)	77 (10)	65 (7)	.07
Not low income (>500 € per month)	709 (90)	822 (93)
Mean self-rated health (sd)*	3.12 (0.76)	3.13 (0.76)	.68
With a chronic condition
Yes	232 (32)	227 (27)
No	497 (68)	600 (73)	.06
Baseline distribution of BSI depression normative scores
Very low	0 (0)	0 (0)	.38
Low	0 (0)	0 (0)
Below average	113 (14)	145 (16)
Average	196 (25)	234 (26)
Above average	284 (36)	324 (37)
High	168 (21)	162 (18)
Very high	25 (3)	22 (2)

DOI: 10.7717/peerj.311/table-1

Notes:

Figures in this table are n (%) except for age and self-rated health which are mean (sd).

* Rated on a scale of 1–5, with higher scores indicating better health.

Results

Religious attenders were more likely to be female, older, and married as compared to non-attenders. Attenders and non-attenders were similar in self-rated health, in the proportion having chronic conditions, and in the distribution of BSI Depression normative scores. From March to September 2008, 491 individuals developed elevated depression. The chi-square tests in each of the four follow-up waves showed no association between depression status and subsequent decrease in attendance with one exception. In 2012, those with elevated BSI Depression among baseline attenders were more likely to keep or increase their 2008 attendance levels. In post-hoc analysis, we repeated the change in attendance analysis by depression category stratified first by gender and then by age category. In gender-stratified analysis, no associations were found in each attendance follow-up. In age-stratified analysis, no associations were found in the first two years after depression assessments took place. In both R₃ and R₄, those 48 years old and above and with elevated depression were more likely to maintain or increase attendance levels (both p’s < .05). (See Table 2. The tables stratified by gender or age category are available from the authors by request.)

In multinomial logistic regression modeling, elevated symptoms predicted lower probability of a decrease in attendance (relative risk ratio = 0.55, 95% CI [0.38–0.79]) relative to baseline attendance levels among attenders (see Table 3 and Fig. 2). Among non-attenders, elevated symptoms were unrelated to a subsequent increase in attendance with one exception. The estimates were not materially different when the models were run using multiply imputed data.

Discussion

The main finding in this study is that elevated BSI depression does not cause a subsequent decrease in attendance. On the contrary, elevated BSI depression predicts same or increased levels of attendance as compared with prior to elevated BSI depression. None of our results across three analytical strategies showed a decrease in attendance. Although unstratified analyses did not yield a significant association, gender and age-stratified results indicated an association of continued or increased attendance with elevated symptoms. We do not interpret this association because other variables could possibly explain the association. The multinomial logistic model among attenders, with covariates controlled for, indicated that elevated symptoms predicted same or increased attendance. As a secondary finding, non-attenders were not likely to seek recourse in religion by starting to attend services.

Our main finding addresses the issue of selection bias in studies of religious attendance and mental health. To recap, when depressed individuals stop attending services, the apparent protection afforded by attendance would be inflated. This selection bias would be most pronounced in cross-sectional studies. In longitudinal epidemiologic studies, bias remains an issue because there might be differential attrition in attendance by depression status. Since we found that attenders who develop elevated symptoms become less likely to drop out of worship, then they might in effect be overrepresented among churchgoers. Therefore, the protective effect of religious attendance might in fact be underestimated, contrary to the reverse causation argument.

Religious individuals turn to their faith in times of distress as a means of coping (Brown et al., 2004; Bussing, Ostermann & Koenig, 2007; Ironson, Stuetzle & Fletcher, 2006). Religious worship is a source of social support and allows individuals to cope with life-threatening conditions by providing “medicine for the spirit” (Cummings & Pargament, 2010). A longitudinal study (Li & Ferraro, 2005) on depression and volunteering among older adults reported that elevated depression at wave 2 predicted seeking out volunteering opportunities at wave 3. This was explained as a compensatory mechanism to alleviate negative affect, via social integration. These older adults had physical health problems in addition to depression and the physical health problems were the operative barriers. Consistent with this finding, Chen & Koenig (2006) reported that in elderly, medically ill individuals, an increased severity of physical illness predicted a decrease in organizational religiousness. Importantly, the association was completely mediated by physical activity limitations. Together with our own results, these suggest that it is not depression per se that causes a disengagement from participation in religious service. In effect, reverse causation and non-random attrition might be more relevant to studies examining religious attendance and physical health.

The null association of elevated depression with subsequent attendance among non-attenders indicates that non-attenders do not start attending in the face of adversity. By contrast, Ferraro & Kelley-Moore (2000) reported that depression, cancer, and chronic conditions lead to consolation-seeking even among those with no religious affiliation. The two points of view can be reconciled because attendance is not necessary for consolation-seeking. The need to find meaning in illness is shared by believers and non-believers who may turn to nature, arts, music, and relationships (Burnard, 1988).

An intriguing study (Farias et al., 2013) reported that rowers about to enter a competition reported greater belief in science as compared with those in a training session. The authors concluded that affirming one’s secular worldview serves a similar function as religious faith in moments of stress or existential anxiety. Hence, affiliated individuals cope by means of religion while non-attending ones seek support and meaning elsewhere. It appears that depressive symptoms are not a strong driver of entry into or exit from the churchgoing demographic. More empirical research is needed to validate this interpretation.

Our study has several important limitations. First, we relied on the depression subscale of the BSI to assess depressive symptoms. It has been argued that although the global BSI scale is a valid measure of distress, it is not intended to screen for particular psychiatric disorders (Asner-Self, Schreiber & Marotta, 2006). We set the BSI cut-off for depression at “high” or “very high” but there is no way to tell whether this is in concordance with clinically diagnosed depression. We therefore allow for the possibility that the depressed group that we studied might differ from a group with formally diagnosed major depression (Sareen et al., 2013). Secondly, there were no assessments of depression from 2009 to 2012—the period during which religious attendance was compared to initial attendance. As such, all religious attendance changes were indexed to depression levels in 2008 only. We cannot rule out the possibility that attendance levels after 2008 were related to unmeasured elevated symptoms after 2008. Third, the sample that we worked with was restricted to LISS participants who responded to both religion and mental health modules and might not be representative of the Dutch national population. Fourth, while we have ruled out sampling bias in terms of attrition in attendance, we could not address whether personality traits such as greater resilience to depression characterized attenders in the first place. Finally, other health-related reasons, including physical disability, might be correlated with depression and could cause selection bias. This is beyond the scope of our study. The major strength of this study was that depression assessments were proximal to those of religion. Our sample also consisted of a small fraction (5%) of late adolescents and is less affected by the well-reported decline in religious attendance in adolescence.

Within the limitations of our study, we conclude that elevated depressive symptoms do not cause religiously affiliated individuals to subsequently decrease attendance at religious services.