Insight and medication adherence in schizophrenia: An analysis of the CATIE trial

Julia Kim; Miracle Ozzoude; Shinichiro Nakajima; Parita Shah; Fernando Caravaggio; Yusuke Iwata; Vincenzo De Luca; Ariel Graff-Guerrero; Philip Gerretsen

doi:10.1016/j.neuropharm.2019.05.011

Insight and medication adherence in schizophrenia: An analysis of the CATIE trial

Neuropharmacology. 2020 May 15:168:107634. doi: 10.1016/j.neuropharm.2019.05.011. Epub 2019 May 9.

Authors

Julia Kim¹, Miracle Ozzoude², Shinichiro Nakajima³, Parita Shah¹, Fernando Caravaggio⁴, Yusuke Iwata⁴, Vincenzo De Luca⁵, Ariel Graff-Guerrero⁶, Philip Gerretsen⁷

Affiliations

¹ Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.
² Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada.
³ Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada; Department of Neuropsychiatry, Keio University, Tokyo, Japan.
⁴ Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
⁵ Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Division, CAMH, University of Toronto, Toronto, Ontario, Canada; Schizophrenia Division, CAMH, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, CAMH, Toronto, Ontario, Canada.
⁶ Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Division, CAMH, University of Toronto, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, CAMH, Toronto, Ontario, Canada.
⁷ Multimodal Imaging Group, Research Imaging Centre, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Geriatric Mental Health Division, CAMH, University of Toronto, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, CAMH, Toronto, Ontario, Canada. Electronic address: philgerretsen@yahoo.com.

PMID: 31077729
DOI: 10.1016/j.neuropharm.2019.05.011

Abstract

Adherence to antipsychotic medication is critical for the treatment of patients with schizophrenia. Impaired insight into illness is one of the principal drivers of medication nonadherence, which contributes to negative clinical outcomes. The aims of this study were to examine the relationships between impaired insight and (1) rates of antipsychotic medication nonadherence, and (2) time to medication nonadherence using data from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) study. Insight was assessed using the Positive and Negative Syndrome Scale (PANSS) item G12 (lack of judgment and insight). Patients were divided into 3 groups based on their degree of insight impairment, i.e. no impairment (PANSS G12 = 1), minimal impairment (PANSS G12 = 2-3), and moderate-to-severe insight impairment (PANSS G12 ≥ 4). Medication nonadherence was defined as taking less than 80% of monthly pill counts. Kaplan-Meier survival and Cox regression analyses were performed to examine differences in time to medication nonadherence between insight groups. There were significant differences between insight groups in the percentage of nonadherent patients at 6 months (χ²(2) = 8.80, p = 0.012) and 18 months (χ²(2) = 10.04, p = 0.007) after study initiation. Moderate-to-severe insight impairment was associated with earlier nonadherence compared to minimal (χ² = 4.70, p = 0.030) or no impairment (χ² = 11.92, p = 0.001). The association remained significant after adjustment for illness severity, substance use, attitudes toward medication, cognition, level of hostility, and depression. The results of this study indicate a strong link between impaired insight and antipsychotic medication nonadherence. Interventions to enhance insight early during treatment may help improve medication adherence, and in turn, long-term clinical and functional outcomes in patients with schizophrenia. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

Keywords: Antipsychotic; Illness awareness; Insight; Medication adherence; Schizophrenia.

Publication types

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

MeSH terms

Adult
Antipsychotic Agents / therapeutic use*
Female
Humans
Male
Medication Adherence / psychology*
Middle Aged
Psychiatric Status Rating Scales
Schizophrenia / diagnosis*
Schizophrenia / drug therapy*
Schizophrenic Psychology*
Treatment Outcome

Substances

Antipsychotic Agents

Abstract

Publication types

MeSH terms

Substances

Grants and funding