Background There is a paucity of evidence supporting the effectiveness of diabetes self-management education (DSME) in improving mental health-related quality of life (HRQoL) for African PI-103 Hydrochloride American and Latinos. African Americans and Latinos 55?years or older with poorly controlled diabetes (HbA1c?≥?8.0%) recruited from senior centers and churches in Los Angeles. The intervention group received six weekly small-group self-care sessions based on the empowerment model. The control group received six lectures on unrelated geriatrics topics. The primary outcome variable in this secondary analysis was the change in Mental Component Summary score (MCS-12) from the SF-12 Health Survey between baseline and six-month follow-up. We used the change in HbA1c during the study period as the main mediator of interest in our causal mediation analysis. Additionally possible mediations via social support and perceived empowerment attributable to the program were examined. Results MCS-12 increased by 1.4 points on average in the intervention group and decreased by 0.2 points in the control group (difference-in-change: 1.6 points 95 CI: 0.1 to 3.2). In the causal mediation analysis the intervention had a direct effect on MCS-12 improvement (1.7 points 95 CI: 0.2 to 3 3.2) with no indirect effects mediated via HbA1c change (?0.1 points 95 CI: ?0.4 to 0.1) social support (0.1 points) and perception of empowerment (0.1 points). Conclusions This Diabetes Self-Care Research empowerment treatment had a moderate positive effect on mental HRQoL not really mediated from the improvement in glycemic control in addition to cultural support and notion of empowerment. This favorable influence on mental HRQoL may be another clinical benefit of this DSME intervention. Trial Sign up ClinicalTrial.gov NCT00263835. Electronic supplementary materials The online edition of this content (doi:10.1186/s12913-015-0779-2) contains supplementary materials which is open to authorized users. Keywords: Randomized managed trial Diabetes mellitus Self-management Individual education Mental wellness Background Diabetes can be an essential public wellness concern not merely due to the immediate morbidity and mortality it causes but additionally because it plays a role in many other health issues including micro- and macro-vascular illnesses. Diabetes disproportionately impacts BLACK and Latino PI-103 Hydrochloride populations through both socioeconomic and genetic elements [1] probably. Diabetes can be associated with poorer mental working as evidenced by its association with lower mental health-related standard of living (HRQoL) in population-based study PI-103 Hydrochloride [2]. The current presence of diabetes doubled the chances of comorbid melancholy in a released meta-analysis [3]. The causal romantic relationship between diabetes and impaired mental wellness is regarded as bidirectional with each condition exacerbating another [4]. Consequently when healthcare companies see a individual with diabetes they ought to screen for melancholy along with other diabetes-related psychosocial problems and if present treat them because these problems may interfere with maintaining control of diabetes [5]. There is also an increasing interest in the relationship between diabetes treatment options and psychological outcomes [6]. Self-management is an integral part of controlling diabetes. For example optimal glucose control in most cases requires patients to maintain healthy eating and appropriate exercise. Diabetes self-management education (DSME) has F2RL1 been described as “a collaborative process through which people with or at risk for diabetes gain the knowledge and skills needed to modify behavior and successfully self-manage the disease and its related conditions [7]”. There is considerable evidence that DSME improves glycemic control albeit modestly (Figure?1A) [8 9 In addition several researchers have hypothesized that DSME improves psychological aspects through a positive attitude toward health and increased diabetes self-efficacy (Figure?1B). For example Kirk et al. reported that exercise consultation compared to standard care improved the mental health subscale of SF-36 5?weeks after the intervention in a small randomized controlled trial (RCT) among patients with Type 2 diabetes (T2DM) [10] However other studies of DSME showed either no effect or worsened mental HRQoL [11-13]. A few systematic.