Mindfulness in treatment-seeking adults with comorbid obsessive-compulsive and major depressive disorders: Mediating effects of obsessive beliefs and mental well-being

Abstract

Background:

Mindfulness-based interventions have shown promise in alleviating symptoms associated with obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). However, the specific mechanisms that drive these effects, mainly through obsessive beliefs and mental well-being, are seldom examined.

Aim:

To explore the mechanisms by which mindfulness influences symptom severity in adults with comorbid OCD and MDD, focusing on the mediating roles of obsessive beliefs and mental well-being.

Methods:

Primary data from 60 treatment-seeking adults with comorbid OCD and MDD were analyzed. Ordinary least-squares path analysis was employed to examine the mediating roles of obsessive beliefs and mental well-being in the relationship between mindfulness and the severity of OCD and MDD symptoms.

Results:

Mindfulness was significantly associated with reduced symptom severity for both OCD (β = − 0.40, P < 0.001) and MDD (β = − 0.49, P < 0.001). For MDD, obsessive beliefs (β = − 0.20, P < 0.001) and mental well-being (β = − 0.33, P < 0.001) significantly mediated the relationship. In contrast, no significant indirect effects were observed for OCD symptoms through obsessive beliefs (β = − 0.10, P = 0.16) or mental well-being (β = − 0.08, P = 0.20).

Conclusion:

These findings highlight the distinct mechanisms of mindfulness in comorbid OCD and MDD, underscoring the importance of customized interventions based on specific pathways.

INTRODUCTION

Mindfulness-based interventions (MBIs) have garnered significant attention in recent years for their potential to address a range of psychiatric conditions, including obsessive-compulsive disorder (OCD) and major depressive disorder (MDD).[1,2,3] These disorders, often comorbid, present unique clinical challenges due to their overlapping and mutually exacerbating symptoms, such as intrusive thoughts, compulsive behaviors, and persistent mood disturbances.[4] While existing research has demonstrated the efficacy of MBIs in reducing symptom severity in OCD and MDD independently,[5,6] there is a notable gap in understanding the specific mechanisms through which mindfulness exerts its effects,[1] particularly in cases of comorbidity.[7,8] This study seeks to address this gap by examining the mediating roles of obsessive beliefs and mental well-being in the relationship between mindfulness and symptom reduction in individuals with comorbid OCD and MDD.

The co-occurrence of these disorders is common, with approximately 60% of OCD patients experiencing concurrent depressive symptoms,[9] exacerbating clinical challenges and complicating treatment outcomes.[4,10] While traditional therapies, such as Cognitive Behavioral Therapy (CBT) and pharmacotherapy, are effective in addressing individual symptoms of OCD and MDD,[10,11] these approaches often fail to address the complex interplay of symptoms fully and shared cognitive distortions in comorbid cases.[12] Furthermore, symptom severity and pharmacological treatment may influence the effectiveness of mindfulness-based approaches, yet limited research has explored these factors in individuals with comorbid OCD and MDD.[13]

MBIs have emerged as a promising therapeutic approach for various psychological disorders, including OCD and MDD.[14] MBIs such as Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT) focus on fostering present-moment awareness and reducing reactivity to intrusive thoughts, making them particularly effective in alleviating rumination and compulsions.[15,16] Recent meta-analyses have highlighted the efficacy of MBIs in reducing relapse rates in recurrent depression and managing OCD symptoms, particularly when integrated with standard therapeutic modalities.[17] Despite these promising findings, there is a limited understanding of how MBIs impact comorbid OCD and MDD and the mechanisms underlying their effectiveness.

This study builds on these insights by examining how obsessive beliefs and mental well-being mediate the relationship between mindfulness and symptom reduction in comorbid OCD and MDD. By investigating these pathways, the study addresses a significant gap in the literature, providing a foundation for tailored, mechanism-focused interventions.[5,6,18]

MATERIALS AND METHODS

In the initial phase, participants were informed about the nature and format of the study. Institutional Ethics Committee clearance was obtained. In keeping with the ethical standards, participation in this study was strictly voluntary, and participants could decline to participate at any point during the study.

Participants

A clinical sample of 60 adults seeking treatment was recruited between November 2022 and September 2023. All participants met the ICD-10 Diagnostic Criteria for Research[19] for comorbid OCD and MDD, with their diagnoses confirmed by their psychiatrists. This study focused solely on analyzing data from the baseline assessment, without examining information from intervention or treatment sessions for this paper. The sample size of 60 was determined through a G*Power analysis to ensure sufficient power to detect the anticipated effect. The power calculations indicated that with a risk ratio of 2.3, the sample achieved a power of 89.29% (using normal approximation) and 82.84% (with continuity correction), surpassing the conventional threshold of 80%. This minimizes the likelihood of Type II errors and reinforces the study’s capacity to identify significant effects. These considerations align with existing literature, which suggests that smaller sample sizes can still yield reliable mediation analysis results, particularly when power requirements are met, especially in clinical populations with psychiatric comorbidities.[20] Figure 1 illustrates the sampling procedure, screening process and data analysis plan.

Figure 1.

Flow of participants through the study. After screening, eligible participants underwent sociodemographic and clinical assessments. Data analysis included Ordinary Least Squares (OLS) path analysis with 1,000 bootstrapped samples

Measures

We collected the socio-demographic details of the participants, such as age, gender, education, occupation, and marital status. We also collected a comprehensive case history using Mayer-Gross[21] proforma. We also used a clinical data sheet to collect information about the nature of the illness, history of psychological disorder, psychological treatment at present, history of any psychological treatment, and current medication use. We obtained participants’ medication statuses, paying particular attention to the use of selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, tricyclic antidepressants, and serotonin–norepinephrine reuptake inhibitors (SNRIs). Given the potential impact of these medications, we viewed their use as a confounding factor that could affect the relationship between mindfulness, symptom severity, obsessive beliefs, and overall mental well-being, and so not include them in the present study.

We used the Yale-Brown Obsessive-Compulsive Scale – Second Edition (YBOCS-II)[22] to measure the severity of OCD symptoms. This tool offers a comprehensive assessment through its ten-item scale, providing a total score ranging from 0 to 50. Its psychometric properties, including high-reliability coefficients such as Cronbach’s alpha of 0.86 for internal consistency and an Intraclass Correlation Coefficient (ICC) of 0.97-0.99 for inter-rater reliability, ensure its credibility.[23]

The Beck Depression Inventory-second Edition (BDI-II)[24] was administered to assess the severity of depressive symptoms. Consisting of 21 items, each rated on a 4-point scale (0–3), the BDI-II has a higher score correlating to more severe symptoms. It has excellent internal consistency and tests re-test reliability (α > 0.9 for both). Additionally, its concurrent validity with the Hamilton Psychiatric Rating Scale for Depression-Revised is well-established, evidenced by a correlation coefficient of 0.71.[25]

The Obsessional Beliefs Questionnaire-Revised (OBQ-44),[26] a 44-item self-report measure, was used to evaluate OCD-related cognitions. Each item was rated on a 7-point scale (1–7), assessing obsessive-compulsive thoughts comprehensively. The scale has excellent internal consistency, with Cronbach’s alpha coefficient exceeding 0.89 for each sub-scale. The total score on the OBQ-44 distinguishes between people diagnosed with OCD and non-OCD anxious controls.[26]

The Short Warwick-Edinburgh Mental Well-Being Scale[27] is a concise 7-item measure designed to assess well-being with responses rated on a 5-point scale (1-5), where scores > 40 signify greater well-being.[28] Strong internal consistency, test–retest reliability, Cronbach’s alpha score of 0.89 (student sample) and 0.91 (population sample), and concurrent validity found that the measure is sensitive to changes in mental health populations.[29]

Five-Facet Mindfulness Questionnaire (FFMQ-39), developed by Baer et al.[30] and further validated by Bohlmeijer et al.,[31] is a widely used tool for assessing mindfulness. It includes 39 items rated on a 5-point Likert scale, where 1 represents “Never or very rarely true,” and 5 represents “Very often or always true.” Higher scores reflect greater levels of mindfulness. The FFMQ-39 assesses five distinct facets of mindfulness: observing, describing, acting with awareness, non-judging of inner experience, and non-reactivity to inner experience. It demonstrates adequate reliability, with Cronbach’s alpha coefficient exceeding 0.73 for each sub-scale, ensuring consistency in measurement.[31]

Procedure

Before gathering data, participants received a comprehensive overview of the study’s objectives, procedures, and ethical guidelines outlined in a participant information sheet. The initial steps involved establishing rapport with the participants, followed by a thorough briefing on the study. Once participants thoroughly understood the research, they were asked to provide their written informed consent. We ensured that the confidentiality of their information was strictly protected, and participants were made aware of their right to withdraw from the study at any time without any negative consequences. During the assessment phase, we provided participants with instructions for all psychological measures by their respective manuals. Testing was conducted individually to ensure consistency and minimize potential biases. Moreover, we obtained consent from a psychiatrist to verify each participant’s diagnosis, ensuring compliance with clinical standards. Participants who did not meet the inclusion criteria were referred to alternative treatment resources, upholding a commitment to ethical care for all individuals involved.

Statistical analysis

The ordinary least-squares path analyses were conducted to examine the mediating effects of obsessive beliefs and mental well-being on the relationship between mindfulness and OCD and MDD symptoms. For OCD and MDD symptoms, the indirect effects of mindfulness through obsessive beliefs and mental well-being were tested using the bootstrapping procedure, with significance assessed using a 95% confidence interval based on 1,000 bootstrap samples. All statistical analyses were performed using Jamovi version 2.3.21.[32] For the ordinary least-squares path analysis, we used the mediation module within Jamovi and conducted the bootstrapping method.[33]

RESULTS

Descriptive statistics for participants’ sociodemographic characteristics and clinical characteristics are presented in Table 1. This table provides an overview of the sample composition, including age, gender, education, occupation, and marital status, as well as baseline clinical characteristics such as OCD severity, depression severity, obsessive beliefs, mindfulness, mental well-being, and medication status. These data establish the baseline psychological profile of participants and help contextualize subsequent analyses.

Table 1.

Sociodemographic and clinical characteristics of the participants (n=60)

Variable	Category/M (SD)	n (%)/Range
Age (years)	29.10 (7.71)	18–46
Gender	Male	35 (58.3)
	Female	25 (41.7)
Education	10th Grade	1 (1.7)
	12th Grade	9 (15.0)
	Undergraduate	27 (45.0)
	Postgraduate	21 (35.0)
	Doctorate	2 (3.3)
Occupation	Employed	18 (30.0)
	Unemployed	15 (25.0)
	Student	27 (45.0)
Marital Status	Married	19 (31.7)
	Unmarried	39 (65.0)
	Divorced	2 (3.3)
Y-BOCS (OCD Severity)	29.47 (3.75)	19–37
BDI-II (Depression Severity)	34.80 (9.73)	15–54
OBQ-44 (Obsessive Beliefs)	237.50 (30.83)	152–288
FFMQ-39 (Mindfulness Score)	79.72 (19.10)	45–135
SWEMWBS (Mental Well-Being)	30.42 (5.70)	20–46
Medication Use	Yes	32 (53.3)
	No	28 (46.7)

Age is reported as M (SD). Gender, education, occupation, and marital status are presented as n (%). Y-BOCS=Yale-Brown Obsessive-Compulsive Scale; BDI-II=Beck Depression Inventory-II; OBQ-44=Obsessive Beliefs Questionnaire-44; FFMQ-39=Five Facet Mindfulness Questionnaire-39; SWEMWBS=Short Warwick-Edinburgh Mental Well-Being Scale

Following the demographic and clinical data overview, the results indicated a significant direct negative effect of mindfulness on OCD symptoms (β = −0.40, P < 0.001), suggesting that higher levels of mindfulness are associated with reduced OCD severity [Table 2].

Table 2.

Mediation Test Results: The Effects of Mindfulness on OCD Through Obsessive Beliefs and Mental Well-being

Indirect and Total Effects
Type	Path	Estimate	SE	95% C.I. (a)		β	Z	P
				Lower	Upper
Indirect	MF ⇒ OB ⇒ OCD	-0.02	0.01	-0.05	0.01	-0.10	-1.40	0.16
	MF ⇒ MW ⇒ OCD	-0.02	0.01	-0.04	0.01	-0.08	-1.27	0.20
Component	MF ⇒ OB	-0.75	0.23	-1.19	-0.31	-0.46	-3.32	<0.001
	OB ⇒ OCD	0.03	0.01	0.00	0.06	0.22	1.83	0.07
	MF ⇒ MW	0.16	0.03	0.11	0.22	0.55	5.83	<0.001
	MW ⇒ OCD	-0.10	0.08	-0.26	0.05	-0.15	-1.28	0.20
Direct	MF ⇒ OCD	-0.08	0.02	-0.12	-0.03	-0.40	-3.43	<0.001
Total	MF ⇒ OCD	-0.11	0.02	-0.16	-0.07	-0.59	-5.42	<0.001

CI, Confidence Interval; MF, Mindfulness; OB, Obsessive Beliefs; MW, Mental Well-Being; OCD, Obsessive-compulsive Disorder; SE, Standard Error; β, Unstandardized Coefficient

Additionally, mindfulness significantly reduced obsessive beliefs (β = −0.46, P < 0.001) and enhanced mental well-being (β = 0.55, P < 0.001). However, the indirect effects of mindfulness on OCD symptom severity through obsessive beliefs (β = −0.10, P = 0.16) and mental well-being (β = −0.08, P = 0.20) were not statistically significant. The total effect of mindfulness on OCD symptoms was negative and significant (β = −0.59, P < 0.001) as illustrated in Figure 2.

Figure 2.

Mediation model illustrating the relationships between mindfulness (independent variable), obsessive-compulsive disorder (dependent variable), and obsessive beliefs and mental well-being (mediators), using unstandardized coefficients. p < 0.01 (two-tailed). Dashed lines indicate non-significant pathways; solid lines indicate significant pathways. Abbreviations: MF = Mindfulness; OB = Obsessive Beliefs; MW = Mental Well-being; OCD = Obsessive-Compulsive Disorder. Standardized coefficients are reported from structural equation modeling (path analysis)

The path analysis illustrated relationships between mindfulness, mental well-being, obsessive beliefs, and OCD symptoms. Mindfulness significantly reduced obsessive beliefs (β = −0.75) and enhanced mental well-being (β = 0.16). However, obsessive beliefs exerted a negligible positive effect on OCD symptoms (β = 0.03), while mental well-being had a weak negative effect (β = −0.10). The direct impact of mindfulness on OCD symptoms was statistically significant (β = −0.08, P < 0.001).

The results also demonstrated that mindfulness had a significant negative indirect effect on depression through both obsessive beliefs (β = −0.20, P < 0.001) and mental well-being (β = −0.33, P < 0.001) [Table 3].

Table 3.

Mediation Test Results: The effects of mindfulness on depression through obsessive beliefs and mental well-being

Indirect and Total Effects
Type	Path	Estimate	SE	95% C.I.		B	Z	P
				Lower	Upper
Indirect	MF ⇒ OB ⇒ DEP	-0.10	0.03	-0.16	-0.04	-0.20	-3.12	<0.001
	MF ⇒ MW ⇒ DEP	-0.17	0.04	-0.25	-0.08	-0.33	-3.99	<0.001
Component	MF ⇒ OB	-0.75	0.18	-1.11	-0.39	-0.46	-4.06	<0001
	OB ⇒ DEP	0.13	0.03	0.08	0.19	0.43	4.87	<0.001
	MF ⇒ MW	0.16	0.03	0.10	0.23	0.55	5.05	<0.001
	MW ⇒ DEP	-1.01	0.16	-1.32	-0.71	-0.60	-6.53	<0.001
Direct	MF ⇒ DEP	0.02	0.05	-0.08	0.12	0.04	0.40	0.69
Total	MF ⇒ DEP	-0.24	0.06	-0.36	-0.13	-0.49	-4.29	<0.001

CI, Confidence Interval; MF, Mindfulness; OB, Obsessive Beliefs; MW, Mental Well-Being; DEP, Depression; SE, Standard Error; β, Unstandardized Coefficient

Mindfulness significantly reduced obsessive beliefs (β= −0.46, P < 0.001) and improved mental well-being (β = 0.55, P < 0.001). However, the direct effect of mindfulness on depression was not statistically significant (β = 0.04, P = 0.69). Overall, the total effect of mindfulness on depression remained strong (β = −0.49, P < 0.001) as depicted in Figure 3.

Figure 3.

Mediation model illustrating the relationships between mindfulness (independent variable), depression (dependent variable), and obsessive beliefs and mental well-being (mediators), using unstandardized coefficients. p < .001 (two-tailed). Dashed lines indicate non-significant pathways; solid lines indicate significant pathways. Abbreviations: MF = Mindfulness; OB = Obsessive Beliefs; MW = Mental Well-being; DEP = Depression. Standardized coefficients are reported from structural equation modeling (path analysis)

The path analysis illustrated the relationships between mindfulness, mental well-being, obsessive beliefs, and depression. Mindfulness had a significant positive effect on mental well-being (β = 0.16) and a significant adverse effect on obsessive beliefs (β = −0.75). However, the direct effect of mindfulness on depression was not substantial (β= -0.54). Mental well-being showed a significant adverse effect on depression (β = −0.01), while obsessive beliefs had a significant positive impact on depression (β = 0.13).

DISCUSSION

The present study explored the association between mindfulness and symptom severity in comorbid OCD and MDD among treatment-seeking adults.

Our findings demonstrate that mindfulness is a significant factor in diminishing OCD symptoms. The negative direct effect of mindfulness on OCD symptom severity suggests that individuals practicing mindfulness experience symptom relief independent of reductions in obsessive beliefs or improvements in mental well-being. This diverges from the findings of prior studies that often emphasized intermediary pathways.[34] One possible explanation for this phenomenon could be the cognitive rigidity commonly associated with OCD. In contrast to depressive symptoms, which may be more amenable to cognitive reframing, OCD symptoms are often deeply entrenched in persistent maladaptive patterns that are unlikely to change solely through alterations in obsessive beliefs.[35] Consequently, mindfulness may primarily exert its therapeutic effects on OCD by promoting a non-reactive stance toward intrusive thoughts, rather than directly altering their content. This direct pathway may clarify why mindfulness has shown a significant overall impact on OCD symptoms, even in the absence of significant mediation effects.

Previous studies, such as those by Leeuwerik et al.,[36] have established mindfulness as inversely related to OCD symptoms, demonstrating that mindfulness predicts OCD severity better than self-compassion. The present study findings extend this by showing mindfulness’s direct effects, independent of cognitive mediators, underscoring its primary role in symptom alleviation. Additionally, this contrasts with the depression model may reflect differences in how these conditions respond to MBIs. While mindfulness appears to influence depression by improving emotional regulation and reducing maladaptive beliefs, its impact on OCD may rely more heavily on disengagement from intrusive thoughts through processes like decentering.[37] Theoretical models explain this impact, such as the meta-cognitive model of decentering and the neuro-cognitive model of self-distancing.[38] These models suggest that mindfulness facilitates decentering, allowing individuals to observe intrusive thoughts as transient events rather than engaging with them as self-defining truths.[5,39] Besides, they also foster non-judgmental awareness and reduce cognitive reactivity, breaking cycles of thought-action fusion and compulsive behavior.[2,40]

From a metacognitive perspective, mindfulness interrupts maladaptive processes by shifting individuals’ relationships with their thoughts, viewing them as external rather than intrinsic.[41] This reduces the perceived importance or controllability of intrusive thoughts, breaking the cycle of obsessions and compulsions. Unlike traditional cognitive approaches, which focus on modifying thought content, mindfulness may promote psychological flexibility by changing how individuals relate to their experiences.[42]

These findings underscore the multidimensional benefits of mindfulness. While it reduces obsessive beliefs and promotes well-being, its therapeutic effects on OCD symptoms appear to operate independently of these improvements, offering valuable insights into the nuanced role of mindfulness in comorbid OCD and MDD. Future research could explore whether specific mindfulness facets, such as non-reactivity or acting with awareness, contribute uniquely to these outcomes.

Our findings reveal that mindfulness reduces depressive symptoms indirectly by positively influencing mental well-being and reducing obsessive beliefs. The significant indirect effect of mindfulness through obsessive beliefs suggests that mindfulness helps alleviate depressive symptoms primarily by reducing maladaptive cognitive patterns, such as obsessive beliefs. These beliefs, which include inflated responsibility, perfectionism, and intolerance of uncertainty, are central to the pathophysiology of both OCD and depression.[43] Mindfulness, through processes like cognitive decentering, enhances the ability to detach from these maladaptive thoughts, ultimately leading to improved emotional regulation and reduced depression. These results are consistent with Beck’s cognitive theory, which posits that dysfunctional cognitive schemas, like obsessive beliefs, are critical to the maintenance of depressive symptoms.[12] Furthermore, the role of mindfulness in reducing cognitive rigidity and improving psychological flexibility aligns with previous studies, including those by Teasdale et al.[44] which demonstrated that MBCT can effectively reduce relapse and recurrence by disrupting maladaptive cognitive patterns in individuals with recurrent depression. This highlights the potential of MBIs to alleviate depressive symptoms by fostering cognitive flexibility and emotional regulation.[15] Despite the significant indirect effects, the direct impact of mindfulness on depression was not statistically significant. This suggests that mindfulness’s influence on depression might be more effectively mediated through cognitive mechanisms, such as obsessive beliefs, rather than directly altering depressive symptoms. This is in line with research that suggests MBIs may primarily work by fostering changes in thought processes and emotional regulation rather than directly impacting all aspects of depression.[45] Besides, the significant indirect effects highlight the crucial role of mindfulness in altering cognitive patterns, which in turn leads to emotional regulation and symptom relief.[45] The lack of a direct effect could also reflect that depression, as a multifaceted condition, requires longer or more intensive interventions to observe the immediate effects of mindfulness alone.

Another potential reason for the non-significant direct effect could be related to the complexity of depression itself. Depression is influenced by a multifaceted interplay of cognitive, emotional, social, and biological factors.[46] While mindfulness can reduce specific cognitive distortions, its direct impact on depression might be less pronounced, especially when considering other contributing factors like life stressors or comorbid conditions. Moreover, as the mental well-being constructs in our study capture general positive mental health, the changes in overall well-being brought about by mindfulness might not be immediate or strong enough to produce a significant direct effect on depression within the timeframe of this study.[29]

The significant indirect effect of mindfulness on depression through mental well-being also suggests that improvements in general well-being may play a role in symptom reduction. Existing research provides support for this relationship. For example, Gu et al.[15] demonstrated that MBIs improve emotion regulation and overall well-being, which subsequently reduces depressive symptoms. Similarly, studies suggest mindfulness fosters psychological resilience and self-compassion, enhances mental well-being, and alleviates depressive symptoms.[47] Overall, this study contributes to the existing body of knowledge on mindfulness by employing a robust path analysis approach to explore the role of obsessive beliefs and mental well-being. The use of ordinary least-squares path analysis enables the precise estimation of both direct and indirect effects of mindfulness on comorbid OCD and MDD symptoms, offering a clear distinction in the underlying mechanisms of both disorders. By focusing on a population of adults seeking treatment for comorbid conditions, the study fills a crucial research gap, rendering it more applicable to clinical practice. Additionally, the study’s mediation model advances our comprehension of how specific cognitive and emotional factors impact the effects of mindfulness, providing a methodological framework for future research aimed at understanding the intricate interplay between psychological interventions and mental health outcomes among adults seeking treatment for comorbid OCD and MDD.

The study offers several implications for the treatment and management of comorbid OCD and MDD in adults seeking care. A key implication is the potential role of mindfulness as a treatment component. The findings demonstrate a significant negative relationship between mindfulness and OCD symptoms, suggesting that integrating MBIs may be beneficial for individuals with OCD. Mindfulness practices that foster non-judgmental awareness and reduce cognitive and emotional reactivity could effectively reduce obsessive symptoms.

Given that mindfulness directly reduces OCD symptoms but indirectly alleviates depressive symptoms through obsessive beliefs and mental well-being, its clinical application should be tailored accordingly.

For OCD, mindfulness techniques such as cognitive defusion, decentering, and non-judgemental awareness should be incorporated into EX/RP. These strategies help individuals observe intrusive thoughts without reacting compulsively, thereby reducing thought-action fusion and distress tolerance, both of which reinforce compulsions.[5] MBIs has been shown to improve treatment adherence and symptom reduction.[24] Therapists can guide participants to engage in mindfulness exercises before exposure tasks to enhance distress tolerance and improve EX/RP engagement.

For MDD, where mindfulness influences symptoms indirectly by modifying cognitive patterns and enhancing well-being, structured MBCT or acceptance and commitment therapy maybe more effective.[48] These approaches help address rumination, cognitive rigidity, and emotional dysregulation, which are key contributors to depressive symptoms.[48] Techniques such as mindful attention training, self-compassion exercises, and value-based goal setting can further strengthen psychological resilience and emotion regulation.[47]

Beyond symptom reduction, mindfulness could be implemented as a well-being-enhancing intervention, rather than solely as a symptom-management tool. Given its role in improving mental well-being, MBIs can be combined with behavioral activation and positive psychology strategies to promote long-term resilience.[49] Monitoring both mental well-being and symptom severity may provide a more comprehensive assessment of treatment outcomes.[14] Considering the mutually reinforcing comorbid nature of OCD and MDD symptoms, it is essential to implement a comprehensive treatment plan that addresses both disorders for effective management.

This study has some limitations that warrant recognition. Despite the power analysis confirming sufficient power to detect significant effects, the modest sample size of 60 participants limits generalizability, particularly for mediation analysis in a heterogeneous clinical population. Additionally, variability in medication status and demographic characteristics further restricts the broader applicability of these findings.

Although participants who had engaged in psychotherapy within the last six months were excluded to reduce confounding, medication status and symptom severity may have influenced baseline characteristics and the observed relationship. While we recorded medication use and clinical severity, we did not examine their potential moderating effects on mindfulness. Given that some participants were receiving SSRIs, benzodiazepines, tricyclic antidepressants, or SNRIs, medication use may have influenced the associations between mindfulness, obsessive beliefs and mental well-being.

The sample’s demographic profile presents additional considerations. Although participants’ ages ranged from 18-46 years (M = 29.10, SD = 7.71), the findings may not fully generalize to adolescents and older adults. Additionally, the gender distribution (41.7% female, 58.3% male) introduces a slight imbalance that may further limit generalizability. While 31.7% of participants were married and 30% were employed, the majority were unmarried (65%) and students (45%). This distribution suggests that the findings may be more reflective of younger, academically engaged individuals rather than populations where marital and occupational factors significantly influence mental health and coping mechanisms.

Furthermore, the inclusion of a limited number of variables may restrict the ability to comprehensively account for potential confounding factors. The cross-sectional design can prevent causal inferences, and the reliance on self-report measures may introduce response bias while failing to capture the multidimensional nature of the constructs.

Future research should employ longitudinal designs to better capture the dynamic and evolving nature of these pathways.[50] Additionally, randomized controlled trials could help isolate the casual impact of MBIs by comparing outcomes between intervention and control groups.[51] Recruiting larger, more diverse samples and utilizing objective measures would further enhance understanding by accounting for additional mediators, moderators, and confounding factors.[52]

CONCLUSION

This study emphasizes the crucial role of mindfulness in alleviating symptom severity for individuals with comorbid OCD and MDD. The findings reveal distinct mechanisms through which mindfulness exerts its effects. While enhancements in obsessive beliefs and overall mental well-being serve as significant mediators in the reduction of MDD symptoms, mindfulness appears to directly impact OCD symptoms, independent of changes in obsessive beliefs or mental well-being. This distinction highlights the necessity for customized therapeutic strategies that address the unique pathways relevant to each disorder. Future research should investigate additional mediators and longitudinal effects to refine MBIs for those with comorbid conditions.

Ethical approval

Institutional Ethics Committee clearance was obtained. The study was registered before recruitment commenced (CTRI/2021/10/037545). Registered on 25 October 2021). This study received ethical approval through the Christ University Institutional Review Board CU: (RCEC/00230/09/21).

Key Messages

1. For adults with comorbid OCD and MDD, mindfulness can significantly alleviate OCD symptoms, regardless of obsessive beliefs or mental well-being.

2. To alleviate MDD symptoms, combining mindfulness with cognitive restructuring techniques is advantageous, as obsessive beliefs and mental well-being mediate the treatment process.

3. These insights support customized, pathway-specific intervention.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

This research is part of a broader project funded partially by the ICSSR Centrally-Administered Full-Term Doctoral Fellowship (File No. is RFD/2022-23/GEN/PSY/282) for the academic year 2022-23.