These results show mixed support for our hypotheses. Contrary to expectations, spirituality (i.e., spiritual well-being) was not significantly associated with pre-post reduction in severity of depression, remission from depression or with significant treatment response (≥ 50% reduction in HRSD score). Therefore, level of spirituality was not significantly associated with treatment response to antidepressant medication in this sample.
On the other hand, religiosity was significantly associated with treatment response in this sample; however, this relationship was more complex than we initially hypothesized. Contrary to the linear relationship that we predicted, we found a curvilinear relationship between these two variables. That is, participants in the study who had moderate levels of religiosity responded significantly better to treatment than those who had either lower or higher levels of religiosity. Specifically, participants who had moderate levels of religiosity were significantly more likely to remit by the end of the clinical trial (50% more likely in this sample) and evidenced significantly greater reduction in severity of their depression, with religiosity accounting for 7% of the variance. This strong relationship appears to be independent of baseline severity of depression, final CIT dose, rate of attrition from study, age, gender, ethnicity, and SES. In addition, ethnicity (African-American vs. Caucasian-American) did not moderate the association between religiosity and treatment response to antidepressant medication in our sample which is consistent with evidence suggesting that ethnicity also does not moderate the relationship between religiosity/spirituality and severity of depression (Smith, McCullough & Poll, 2003
). Finally, and contrary to expectation, social support did not mediate this relationship.
Based on the results of this study, it appears that engaging in a moderate amount of religious behaviour might be associated with an enhanced treatment response to antidepressant medication. Some researchers posit that religiosity might have positive effects on mental health outcomes because it is associated with increased access to social support and exposure to spiritual beliefs that aid in benefit finding and positive reappraisal coping (Hill & Pargament, 2003
); however, religiosity does not appear to be operating through these two mechanisms because religiosity was not associated with social support and spiritual-well-being was not associated with the treatment outcomes in this study. Perhaps religiosity aids in treatment response by increasing behavioural activation and/or providing additional means (e.g., prayer, meditation, worship service attendance, etc) to cope with negative mood states. Additionally, some religious practices, such as meditation or prayer, might directly aid in stress reduction by eliciting the “relaxation” response, which is antagonistic to the stress response of the hypothalamic-pituitary-adrenal (HPA) axis (Delmonte, 1985
; Ai et al., 1998
). Finally, individuals who are more religious might have greater expectancy that medical treatment, including treatment with antidepressants, will be more effective (e.g., a belief that God is working through the medication).
If this finding is replicated, it raises the question as to why a moderate level of religiosity is associated with an enhanced treatment response, but higher or lower levels provide no additive benefit. Since this is the first study of its kind, the literature does not offer a direct answer to this question. We propose two non-mutually exclusive explanations for this relationship.
First, it might be that a greater percentage of participants who reported a higher level of religiosity also belong to religious traditions that passively or actively discourage medical treatments for depression. Thus, these participants might not have derived additional benefits from religious practice because practice itself might expose them to information about their disorder that conflicts with information they receive from their healthcare providers and thereby reduce their expectation that the treatment will be effective and/or elicit feelings of guilt or shame about treating their depression with medication. For example, individuals in the higher religiosity group might be more likely to belong to traditions that believe that depression is a “spiritual” disease as opposed to a psychological disorder. In the Apostle Paul’s epistle to the Galatians, he writes that “joy” is one indicator of spiritual health (Galatians 5:19–23, New King James Version). Thus, adherents to religious traditions that interpret this or similar passages literally might believe that the absence of joy (i.e., depression) is an indicator of their “spiritual deficiency” and this belief might promote negative affective states. Unfortunately, this hypothesis could not be tested here, because data on participants’ religious beliefs related to depression and religious denomination membership were not collected.
Alternatively, it could be that many individuals who reported higher religiosity in this study might only exhibit high religiosity during times of stress, but return to a low baseline of religious activity after the stress has abated. Thus, these individuals might appear to be highly religious in a cross-sectional design; however, longitudinal research designs would reveal that these individuals exhibit low stable levels of religiosity. Gall, Kristjannson, Charbonneau & Florack (2009)
argue that individuals who exhibit this pattern might not derive benefits from religiosity, because their religious resources are only utilized during times of stress, and are consequently not developed enough to effectively cope with stressors when they arise. In a study of women undergoing biopsies for breast cancer with low pre-morbid spiritual salience, they found that activation of spiritual resources post-diagnosis predicted poorer psychological adjustment 6 months later. Based on these results, they argue that mobilization of spiritual resources to cope with a stressor might only be effective if an individual maintains high levels of religious/spiritual salience in the absence of stress. Therefore, it is possible that the higher religiosity group failed to exhibit an enhanced response to treatment because many individuals in this group might have been attempting to activate religious resources that were underdeveloped and ineffective due to infrequent use. Of course, this hypothesis rests upon the assumption that individuals who fit this religious profile are over-represented in the higher religiosity group. Unfortunately, since religiosity was assessed cross-sectionally in this study, we are unable to test this assumption because we cannot distinguish between individuals who exhibit high temporary religiosity and those who exhibit high stable levels of religiosity.
Another surprising finding was the lack of an association between scores on the SWB (our measure of spirituality) and treatment response to antidepressant medication; however, this finding does not necessarily mean that spirituality has no association with treatment response. The SWB assesses only one dimension of spirituality (the quality of one’s relationship with God/Higher Being). Although relationship with and attachment to God/Higher Being has been found to be associated with health (see Hill & Pargament, 2003
for a review), it is possible that this dimension of spirituality is not as relevant to pharmacological treatment response as some other dimensions might be (e.g., spiritual meaning and purpose, health-related faith, etc.). Thus, if a comprehensive, multi-dimensional measure of spirituality were used, an association between some facet of spirituality and treatment response might have been obtained.
Although the results of this study are suggestive, there are several limitations that are important to note. First, because religiosity was assessed cross-sectionally and was not manipulated in this design, we cannot make conclusions about causal relationships. Thus, we can only claim that a moderate amount of religiosity appears to be associated with an enhanced response to antidepressant medication. Second, religiosity was assessed at week 3 instead of at baseline; this methodological limitation introduces the possibility that treatment response might have affected religious behaviour rather than the converse. Third, since this study did not include a placebo control group, it is possible, though unlikely, that the observed “treatment response” (e.g., reduction in symptoms, remission) was not due to treatment with CIT, but to some unknown third variable (e.g., spontaneous recovery). In addition, because the study did not include a placebo control group, we cannot conclusively determine from our data whether religiosity is specifically associated with improved response to antidepressant medication or just generally associated with improved recovery from depression. Fourth, since only African-Americans and Caucasians were recruited in this study, it is unknown whether these results will generalize to other ethnic groups. Fifth, the relatively small sample size might have limited power to detect some effects. Finally, since this is the first study to examine the relationship between religiosity, spirituality and treatment response to antidepressant medication, our findings should be replicated before firm conclusions are made from these results.
In conclusion, a moderate amount of religiosity appears to be associated with improved treatment response to antidepressant medication. The results of the present study highlight the importance of understanding religiosity within the context of treatment for depression. If replicated, these findings could have important implications for clinical practice. For example, clinicians could assess patients’ religiosity prior to prescribing antidepressant medication and address religious concerns that might interfere with treatment or promote pre-existing religious behaviour that might benefit treatment. Additional research is also needed to identify some of the biological and psychosocial mechanisms that mediate or moderate this relationship. In future research, religiosity should be assessed longitudinally to determine the direction of causality and to distinguish the effect of acutely activated religiosity (i.e., increase in religious behaviour in response to a crisis) from stable religiosity (i.e. regular religious practices). It is also recommended that researchers employ multi-dimensional measures of religiosity/spirituality to more accurately pinpoint the specific dimensions of religiosity/spirituality that have the strongest associations with treatment response. Finally, additional studies are needed to investigate whether religiosity/spirituality enhances or interferes with treatment response to psychotherapy for depression.