Abstract
Background/Objectives: Adherence to therapeutic recommendations is a key factor influencing treatment effectiveness, particularly in older adults with chronic diseases. Emotional disorders, such as depression and anxiety, may significantly affect adherence and overall health outcomes. The aim of this study was to analyze depressive symptoms and trait anxiety in individuals aged 55 years and older and to determine their association with adherence to therapeutic recommendations. Methods: The study included 2040 participants (1406 women and 634 men) aged 55 to 100 years (mean age: 65 years), all of whom had chronic diseases, most commonly cardiovascular and metabolic conditions. The sociodemographic variables analyzed were age, gender, and education level. Emotional functioning was assessed using the State-Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI). Therapeutic adherence, defined as the extent to which patients followed their treatment plan, was measured with the Adherence in Chronic Diseases Scale (ACDS). Results: ACDS scores ranged from 0 to 28 points, with a mean of 23.84. The majority of participants demonstrated moderate adherence (1149 individuals; 56.3%), followed by high adherence (593 individuals; 29.1%), while low adherence was observed in 298 participants (14.6%). Age and education level were not significantly correlated with adherence (p > 0.05). However, BDI scores showed a weak but statistically significant negative correlation with adherence (r = -0.185; p < 0.05). Similarly, STAI scores demonstrated a weak but significant negative correlation with adherence (r = -0.203; p < 0.05). In addition, BDI and STAI results were moderately correlated with each other (r = 0.453; p < 0.05). No significant differences in adherence were observed between men and women. Conclusions: In this large cohort of over 2000 Polish adults aged 55 years and older with chronic diseases, higher levels of depressive and anxiety symptoms were consistently associated with poorer adherence, with the co-occurrence of both disorders further amplifying this effect. These findings provide confirmatory evidence from an underrepresented Central European population with multimorbidity and underscore the need for systematic mental health screening and adherence-focused interventions in older patients.