Functional impairment in patients with major depressive disorder: the 2-year PERFORM study

Abstract

Background

The Prospective Epidemiological Research on Functioning Outcomes Related to Major depressive disorder (PERFORM) study describes the course of depressive symptoms, perceived cognitive symptoms, and functional impairment over 2 years in outpatients with major depressive disorder (MDD) and investigates the patient-related factors associated with functional impairment.

Methods

This was a 2-year observational study in 1,159 outpatients with MDD aged 18–65 years who were either initiating antidepressant monotherapy or undergoing their first switch of antidepressant. Functional impairment was assessed by the Sheehan Disability Scale and the Work Productivity and Activity Impairment questionnaire. Patients assessed depression severity using the nine-item Patient Health Questionnaire and severity of perceived cognitive symptoms using the five-item Perceived Deficit Questionnaire. To investigate which patient-related factors were associated with functional impairment, univariate analyses of variance were performed to identify relevant factors that were then included in multivariate analyses of covariance at baseline, month 2, months 6 and 12 combined, and months 18 and 24 combined.

Results

The greatest improvement in depressive symptoms, perceived cognitive symptoms, and functional impairment was seen immediately (within 2 months) following initiation or switch of antidepressant therapy, followed by more gradual improvement and long-term stabilization. Improvement in perceived cognitive symptoms was less marked than improvement in depressive symptoms during the acute treatment phase. Functional impairment in patients with MDD was not only associated with severity of depressive symptoms but also independently associated with severity of perceived cognitive symptoms when adjusted for depression severity throughout the 2 years of follow-up.

Conclusion

These findings highlight the burden of functional impairment in MDD and the importance of recognizing and managing cognitive symptoms in daily practice.

Keywords:

• major depressive disorder
• functioning
• functional impairment
• depression
• cognition

Acknowledgments

This study was funded by Lundbeck SAS. The authors thank Professor Martin Knapp (Personal Social Services Research Unit, London School of Economics and Political Science, UK) for his advice regarding the study design and interpretation of the study findings. The authors also thank Mapi for logistical management of the study. The authors would also like to express their gratitude to all the patients and physicians who participated in the study. Writing and editorial assistance was provided by Jennifer Coward of Anthemis Consulting Ltd, funded by Lundbeck SAS.

Disclosure

LHH is a full-time employee of Lundbeck A/S. JMH has received honoraria for being an advisor or providing educational talks for Lundbeck, Otsuka, Roche, and Eli Lilly and Company. BJ has received honoraria for being an advisor to Lundbeck. SDN is a shareholder of Inferential, Paris, France, a provider of biostatistical consulting services working with pharmaceutical companies including Lundbeck. ATM, JC, DM, BR, and DS were full-time employees of Lundbeck at the time this study was conducted. ATM has also been an employee of AbbVie Inc. The authors report no other conflicts of interest in this work.