Non-adherence and negative attitudes towards medication are major problems in treating psychotic disorders. Cytochrome P450 2D6 (CYP2D6) contributes to the metabolism of aripiprazole and risperidone. Variations in CYP2D6 activity may affect treatment response or adverse effects. The impact of these variations on adherence and medication attitudes is unclear.

This study investigates the relationships between CYP2D6 phenotype, self-reported adherence, adverse effects, and attitudes among aripiprazole and risperidone users.

This study analyzed data from the SUPER-Finland cohort of 10,474 adults with psychotic episodes, including 1,429 aripiprazole and 828 risperidone users. The Attitudes towards neuroleptic treatment (ANT) questionnaire assessed adherence and adverse effects in all patients, while medication-related attitudes were examined in a subgroup of 1,000 participants. Associations between CYP2D6 phenotypes and outcomes were analyzed using logistic regression and beta regression in aripiprazole and risperidone groups separately.

Among risperidone users, we observed no association between CYP2D6 phenotypes and adherence, adverse effects, or attitudes. Similarly, no link was found between adherence and CYP2D6 phenotypes among aripiprazole users. However, aripiprazole users with the ultrarapid CYP2D6 phenotype had more adverse effects (OR = 1.71, 95 % CI 1.03–2.90, p = 0.041). Among aripiprazole users, CYP2D6 ultrarapid phenotype was associated with less favorable attitudes towards antipsychotic treatment (β = -0.48, p = 0.023).

We found preliminary evidence that the ultrarapid CYP2D6 phenotype is associated with increased adverse effects and negative attitudes towards antipsychotic medication among aripiprazole users. CYP2D6 phenotype did not influence adherence, adverse effects, or attitudes among risperidone users.

To identify individual-, provider- and system/environmental-level barriers and facilitators affecting cardiac rehabilitation (CR) participants’ adherence to dietary recommendations.

A systematic review of the medical literature was conducted. Six databases were searched from inception through March 2021: APA PsycInfo, CINAHL, Embase, Emcare, Medline and PubMed. Only those studies referring to barriers and facilitators reported by CR participants were considered. Pilot and case report studies, non-peer-reviewed literature and studies published in a language other than English, Portuguese or Spanish were excluded.

Data were extracted and analysed on the basis of individual-, provider- and system/environmental-level factors. Of 2083 initial citations, sixteen studies were included, with nine being qualitative and seven observational in design. From these, ten multi-level barriers and seven multi-level facilitators were identified. Dietary recommendations included developing healthy eating habits, transitioning to vegetarian-rich diets and increasing fish oil and n-3 intake. Only one study reported on all of the nutrition education programme factors recommended by the Workgroup for Intervention Development and Evaluation Research.

To the best of our knowledge, this review is the first to summarise specific barriers and facilitators to recommendation adherence among CR participants. Few of the studies offered any conclusions regarding programme design that could facilitate improved dietary adherence practices. Future studies should aim to explore patient perspectives on the nutritional patterns and recommendations outlined in the Mediterranean Diet, the Dietary Approaches to Stop Hypertension Diet, Vegetarian or Vegan diets and the Portfolio Diet.