The relationship between second-generation antipsychotic medication adherence and negative symptoms in first-episode schizophrenia

Adherence to psychotropic medication is a critical aspect of treatment for the management of psychotic disorders. While the literature on the need for medication adherence is extensive, little research has explored the relationship between the negative symptoms of psychosis and medication adherence. Since negative symptoms are enduring, stable, and strongly correlated with poor outcome, it is vitally important for research to explore the role of negative symptoms in regards to adherence to psychotropic medication. Given its potentially significant consequences for treatment interventions, the purpose of this study was to contribute to the exceedingly limited body of research exploring the relationship between the negative symptoms seen in psychosis and medication adherence. This study examined if there is a relationship between the two and whether causality could be determined should a significant relationship exist between medication adherence and negative symptoms. This study utilized data previously collected at the UCLA Aftercare Research Program for studies examining aspects of outpatient psychiatric treatment. The 148 participants had a mean age of 22.5 years and were in the midst of their first psychotic episode upon study entry. Data from the Brief Psychiatric Rating Scale, Scale for the Assessment of Negative Symptoms, and medication adherence ratings were collected over the course of 12 months. Analyses revealed a significant relationship between the presence of negative symptoms and medication nonadherence. Analyses examining the temporal relationship between the two variables revealed that initial medication nonadherence was significantly associated with subsequent negative symptoms. However, once the impact of positive symptoms was controlled for as a potential mediating variable, the strength of the relationship between medication adherence and negative symptoms dissipated. After controlling for the role of reality distortion, the only negative symptoms significantly associated with medication nonadherence were the BPRS Negative Symptom Factor, BPRS Emotional Withdrawal, and BPRS Self-Neglect. Consequently, it appears that negative symptoms are more strongly associated with positive symptoms than with medication adherence. Replication of these findings and further research exploring the relationship between positive and negative symptoms as they relate to medication adherence is needed in order to improve treatment interventions focused on medication adherence