Patient characteristics associated with the use of antidepressants among people diagnosed with DSM-IV mood disorders: results from the National Comorbidity Survey Replication^*

ABSTRACT

Background: Depression is one of the most common mental illnesses in the United States. However, research on antidepressant usage patterns in a large nationally representative sample is limited.

Objectives: The aims of this study were (1) to examine factors associated with the use of antidepressants in patients with DSM-IV mood disorders, and (2) to determine reasons for inadequate and non-persistent medication taking behaviors.

Research design and methods: A cross-sectional study was conducted using the National Comorbidity Survey Replication (NCS-R) dataset in the U.S. People within the dataset with DSM-IV mood disorders were qualified as the sample population (n = 1798). Selected factors based on the Andersen's Behavioral Model of Health Services Use were assessed among antidepressant users (n = 473) and nonusers (n = 1322). The logistic regression analysis was used to examine the association between the dependent variable, the use of antidepressants, and the independent variables, predisposing, enabling and need factors. Descriptive statistics were used to determine reasons of inadequate and non-persistent medication taking behaviors.

Results: Antidepressant use was more prevalent in patients who were middle age (30–59) (p < 0.01), non-Hispanic white (p < 0.001), unemployed (p < 0.001), living in the South (p < 0.01), having a regular source of care (p < 0.001), and having high severity of emotional distress (p < 0.001). About 41% of patients reported that they forgot to take or took less medication in the study period. Reasons for stopping medication included: “The medication was not helping” (30.8%), followed by “Side effects” (13.8%) and “Couldn’t afford to pay for the medicine” (13.0%).

Limitations: A small sample size in racial/ethnic minority groups; a small sample size in the reasons of stopping taking medications due to the missing values in consecutive questions.

Conclusions: The factors associated with use of antidepressants and reasons of inadequate and non-persistent medication taking behaviors in patients with mood disorders are many and varied. Health care providers need to understand these factors as they work with their patients to improve the likelihood of patients’ successfully to complete their course of treatment.

Key words: :

• Andersen's Behavioral Model of Health Services Use
• Antidepressant
• Bipolar disorder
• Depression
• Dysthymia
• Mood disorders
• Patient characteristics
• Persistence
• Usage patterns

Acknowledgments

Declaration of interest: This study was not funded, and the authors disclose no financial conflicts of interest. This paper was their original work with no editorial assistance provided during the preparation of the manuscript. The authors thank Patricia Berglund, MBA, and Steven G. Heeringa, PhD, from the Institute for Social Research, and Brady T. West, MA, from the Center for Statistical Consultation and Research, University of Michigan, for their assistance in designing statistical codes and guidance of computer programming.

Notes

* Data from this paper were presented in part at The American Pharmacists Association Annual Meeting and Exposition, San Diego, CA, USA, 14–17 March 2008