Prospective memory predicts medication management ability and correlates with non-adherence to medications in individuals with clinically stable schizophrenia.

BACKGROUND: Prospective memory (PM), the ability to remember to carry out an intended action in the future, is thought to relate closely to everyday functioning, such as medication adherence. PM impairment in schizophrenia may contribute to unintentional medication non-adherence. This study aimed to examine the relationship between PM, medication management and medication adherence.
METHODS: Eighty-two stable patients with schizophrenia underwent assessment for PM and medication management ability by laboratory measures at baseline. Clinical symptoms, other neuropsychological functions and risk factors known to associate with non-adherence were also measured. Linear regression was used to identify predictors of medication management ability at baseline. Actual medication adherence was assessed three months later and logistic regression was used to identify predictors of non-adherence.
RESULTS: In the linear regression model, time- and event-based PM together accounted for 72.3% of the variance in the performance of medication management at baseline. At three-month follow-up, the non-adherent group performed significantly more poorly in time- and event-based PM, and had poorer insight, more severe symptoms and poorer ability to manage medications, as compared to the adherent group. In the logistic regression model, insight and PANSS general score significantly predicted non-adherence in the community. Time- and event-based PM moderated the predictive power of insight and PANSS general score.
CONCLUSIONS: Our results support that PM performance robustly predicts medication management ability and may influence medication adherence in the community by moderating the effect of insight and symptom severity. Optimizing PM performance may improve medication adherence in the community, particularly for unintentional non-adherence.