Medication adherence and cognitive performance in schizophrenia-spectrum and bipolar disorder: results from the PsyCourse Study

Abstract

Existing guidelines recommend psychopharmacological treatment for the management of schizophrenia and bipolar disorder as part of holistic treatment concepts. About half of patients do not take their medication regularly, although treatment adherence can prevent exacerbations and re-hospitalizations. To date, the relationship of medication adherence and cognitive performance is understudied. Therefore, this study investigated the relationship between medication adherence and cognitive performance by analyzing the data of 862 participants with schizophrenia-spectrum and bipolar disorders (mean [SD] age, 41.9 [12.48] years; 44.8% female) from a multicenter study (PsyCourse Study). Z-scores for three cognitive domains were calculated, global functioning was measured with the Global Assessment of Functioning Scale, and adherence was assessed by a self-rating questionnaire. We evaluated four multiple linear regression models and built three clusters with hierarchical cluster analyses. Higher adherence behavior (p < 0.001) was associated with better global functioning but showed no impact on the cognitive domains learning and memory, executive function, and psychomotor speed. The hierarchical cluster analysis resulted in three clusters with different cognitive performance, but patients in all clusters showed similar adherence behavior. The study identified cognitive subgroups independent of diagnoses, but no differences were found in the adherence behavior of the patients in these new clusters. In summary, medication adherence was associated with global but not cognitive functioning in patients with schizophrenia-spectrum and bipolar disorders. In both diagnostic groups, cognitive function might be influenced by various factors but not by medication adherence.

Cognitive subgroups of affective and non-affective psychosis show differences in medication and cortico-subcortical brain networks

“…Interestingly, a longitudinal study [77] investigating the e↵ect of anti-psychotic treatment discontinuation showed that those individuals who did not remain on their medication after a 3.5 year follow up had improved significantly more than those who stayed on their medication even when controlling for symptom severity and cognitive scores at baseline. General non-adherence of medication use, however, does not have the same positive e↵ect on cognition [79]. Especially, anticholinergic medication has been associated with a high cognitive burden [78], which is being supported by our results.…”

Cognitive and inflammatory heterogeneity in severe mental illness: Translating findings from blood to brain

“…Cognitive impairment is a major contributor to functional disability in severe mental illnesses (SMI), including schizophrenia (SZ) and bipolar (BD) spectrum disorders (Green, 2006;Wingo et al, 2009). Existing pharmacological treatments have little to no effect on cognitive symptoms (Nielsen et al, 2015;Senner et al, 2023), which may precede illness onset (Dickson et al, 2012;Sheffield et al, 2018) and persist throughout the illness course (Bonner-Jackson et al, 2010;Flaaten et al, 2023Flaaten et al, , 2022. While several pathophysiological mechanisms may be involved (McCutcheon et al, 2023), inflammatory and immunological dysregulation observed in SMI have emerged as a possible contributor to cognitive impairment (Kogan et al, 2020;Misiak et al, 2018;Morozova et al, 2022;Rosenblat et al, 2015).…”