The impact of second-generation antipsychotic adherence on positive and negative symptoms in recent-onset schizophrenia

Kenneth L Subotnik; Joseph Ventura; Denise Gretchen-Doorly; Gerhard S Hellemann; Elisha R Agee; Laurie R Casaus; John S Luo; Kathleen F Villa; Keith H Nuechterlein

doi:10.1016/j.schres.2014.07.008

The impact of second-generation antipsychotic adherence on positive and negative symptoms in recent-onset schizophrenia

Schizophr Res. 2014 Oct;159(1):95-100. doi: 10.1016/j.schres.2014.07.008. Epub 2014 Aug 6.

Authors

Kenneth L Subotnik¹, Joseph Ventura², Denise Gretchen-Doorly², Gerhard S Hellemann², Elisha R Agee², Laurie R Casaus², John S Luo², Kathleen F Villa³, Keith H Nuechterlein⁴

Affiliations

¹ UCLA Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA Aftercare Research Program, University of California, Los Angeles, CA, USA. Electronic address: ksubotnik@mednet.ucla.edu.
² UCLA Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA Aftercare Research Program, University of California, Los Angeles, CA, USA.
³ Genentech, Inc., South San Francisco, CA, USA.
⁴ UCLA Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, UCLA Aftercare Research Program, University of California, Los Angeles, CA, USA; UCLA Department of Psychology, University of California, Los Angeles, CA, USA.

Abstract

Objective: The aim of the study was to explore the extent to which initial severity of positive or negative symptoms in patients with recent-onset schizophrenia is related to medication nonadherence during the first outpatient year.

Methods: The study involved 64 first-episode schizophrenia patients treated with the second-generation oral antipsychotic medication, risperidone, for 12 months. Symptoms were evaluated using the SANS and SAPS completed every 3 months. Pearson correlations between medication adherence and symptoms were examined over each 3-month interval during 12 months of follow-through treatment. Possible causality was inferred from cross-lagged panel analyses.

Results: As expected, higher levels of adherence with antipsychotic medication were generally associated with lower levels of concurrent reality distortion (mean of SAPS delusions and hallucinations). Greater adherence during the 3-month baseline interval was generally associated with lower levels of avolition-apathy as well as alogia throughout the first outpatient year. However, medication adherence was not significantly associated with decreases in avolition-apathy or alogia over time. Cross-lagged panel analyses based on correlation coefficients are consistent with a causal relationship between initial medication adherence and lower levels of alogia. A test of mediation confirmed that an indirect path through reality distortion mediated the relationship between medication nonadherence and alogia.

Conclusions: The associations between greater medication adherence and lower levels of negative symptoms appeared to be accounted for by the relationship of both variables to positive psychotic symptoms. The findings suggest that the impact of second-generation antipsychotic medication on suppression of negative symptoms might be mediated via a reduction in positive symptoms.

Keywords: Adherence; Antipsychotic medication; Cross-lagged panel design; Longitudinal study; Mediation; Negative symptoms.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Acute Disease
Antipsychotic Agents / therapeutic use*
Female
Humans
Male
Medication Adherence*
Psychiatric Status Rating Scales
Risperidone / therapeutic use*
Schizophrenia / drug therapy*
Schizophrenic Psychology*
Treatment Outcome
Young Adult

Substances

Antipsychotic Agents
Risperidone

Abstract

Publication types

MeSH terms

Substances

Grants and funding