Importance of Evaluating Quality of Life in MDD

For patients with major depressive disorder (MDD) taking antidepressants, symptom remission may not correlate with improvements in quality of life (QoL). Assessing QoL offers critical insight beyond symptom reduction, helping clinicians understand how patients perceive their overall well-being. In this video, Dr Diane McIntosh reviews the importance of achieving QoL improvements in MDD and discusses practical clinical tools to help assess real-world QoL outcomes.

Transcript:

Welcome to Psych Navigator’s Clinical Insights series. I’m Dr Diane McIntosh. I’m so happy you’ve joined us today, as we highlight the importance of considering the quality of life of patients living with major depressive disorder, or MDD, as part of their overall psychiatric care.

The Diagnostic and Statistical Manual of Mental Disorders, or DSM-5, describes MDD as a condition characterized by a constellation of symptoms, all of which will impact an individual’s quality of life.¹

These impairments may contribute to the overall burden of the disorder. The Lancet’s Global Burden of Disease Study found that depressive disorders were the second-highest cause of years lived with disability, or DALYs, in 2021.²

Depression symptoms, such as persistently low mood and anhedonia, can impact more than just emotional well-being; they may also interfere with an individual’s personal, social, and professional life and may contribute to a reduction in patients’ overall quality of life.³

According to the World Health Organization, quality of life is an individual's perception of their position in life in the context of the culture and value system in which they live and in relation to their goals, expectations, standards, and concerns.⁴

In essence, quality of life can encompass an individual’s subjective sense of well-being across multiple life domains. These include physical health, occupational engagement, personal beliefs, social relationships, environmental context, autonomy, and engagement in meaningful activities. Quality of life doesn’t just reflect an absence of illness, but also the degree to which an individual perceives their life as being aligned with their goals, values, and expectations.^4,5

Historically, the primary objective in treating MDD has been symptom remission. However, several studies have shown that a patient’s quality of life can remain unsatisfactory even after symptom remission is achieved.³ In fact, there’s growing recognition that quality of life should be considered an equally important therapeutic objective.

For example, the Sequenced Treatment Alternatives to Relieve Depression trial, or STAR*D, evaluated 4,000 adults diagnosed with MDD who were taking antidepressants. It found that a substantial proportion of those who responded to medication continued to report poor quality of life, despite measurable symptom improvement.⁶

In a subsequent analysis of the STAR*D data, which examined how MDD treatment can affect quality of life, over 80% of patients reported a severely diminished quality of life at baseline. Notably, even among those who met remission criteria, 30% to 60% failed to achieve normal quality of life scores, as measured by the self-reported Quality of Life, Enjoyment and Satisfaction Questionnaire, also known as Q-LES-Q.⁶

In addition, among the patients who had gone through four successive acute treatment steps, each following an inadequate response to a previous step, only 9% of MDD patients reported their quality of life was within normal range, compared to about 29% who reported quality of life scores in the normal range after responding to their first treatment.⁶ This underscores the critical importance of optimizing treatment as early as possible to potentially help to improve quality of life in patients with MDD.

Widely used symptom scales such as the PHQ-9, or Patient Health Questionnaire-9,⁷ primarily evaluate the symptoms of MDD, as outlined in the DSM-5 criteria. However, most questionnaires that are designed to assess depression symptoms do not fully capture the broader quality of life and psychosocial consequences of the disorder.

Though valuable, most scales do not assess a patient’s subjective well-being. Research suggests the PHQ-9's focus on symptom frequency may not adequately reflect the diverse and nuanced ways that individuals can be impacted by their symptoms in their daily life.⁷ For instance, a patient being treated for depression may report reduced sadness symptoms while continuing to experience disruptions in their work, school, family, or social functioning.^8,9

This is where the assessment of quality of life becomes crucial in clinical practice.

To evaluate quality of life, clinicians can use tools such as the Short-Form 12 Health Survey, or SF-12.

It’s a validated, health-related quality-of-life measure that isn’t specific to depression but has demonstrated utility across a wide range of clinical populations. Consisting of just 12 questions, the SF-12 is an abbreviated version of the SF-36, so it’s brief and easy to administer in most care settings. On average, the one-page survey can be completed in less than two minutes.^10,11

The SF-12 consists of 8 health domains: the ability to perform physical activities; limitations in daily activities due to physical health; pain severity and its effects on daily activities; self-evaluation of overall health; energy or fatigue; social functioning; limitations in daily activities due to emotional problems; and general mental health.¹⁰

The SF-12 score is comprised of two summary scores: the physical component summary, or PCS, and the mental component summary, or MCS. These scores are calculated using norm-based methods, which are based on the general US population.^12,13

Scores above 50 indicate a better-than-average health status compared to the US population, whereas scores below 50 indicate a below-average health status.¹⁰

Despite being a generic measure, the SF-12 has shown good sensitivity for detecting the impact of depressive disorders on quality of life.¹¹

Once collected, quality of life data can enhance clinical dialogue. For example, if a patient’s symptoms are improving but they are continuing to report poor quality of life, their SF-12 scores may prompt further exploration into unmet need in the management of their MDD and help guide more individual care strategies.¹⁴

The SF-36 and SF-12 measures originated from two large-scale studies, the RAND Health Insurance Experiment and the Medical Outcomes Study, which highlighted the value of self-administered surveys in assessing functional health and well-being.¹⁰

In conclusion, symptom remission doesn’t always translate into an improvement in a patient’s quality of life. In fact, many patients with MDD may continue to experience significant reductions in their quality of life, even after their symptoms have improved or even remitted.

That means it’s important to evaluate symptom reduction as well as assessing your patient’s quality of life.

Quality of life measures can serve as a valuable tool to complement and broaden the clinical perspective and promote shared decision-making with your patients.¹⁴

Incorporating quality of life measures, such as the SF-12, into routine care aligns with the principles of measurement-based care and may facilitate more personalized, goal-directed treatment planning with your patients.

Diane McIntosh, MD, FRCPC 
Diane McIntosh, MD, FRCPC, is a highly regarded psychiatrist and mental health innovator. She is the founder and chief executive officer of RAPIDS Health and Chief Neuroscience Officer at TELUS. She has held numerous prominent positions, including clinical assistant professor at the University of British Columbia and clinical director at the Department of National Defense's Post-Traumatic Stress Disorder Clinic in Nova Scotia. Dr McIntosh is also a published author and recipient of various accolades, including the King Charles III Coronation Medal for her psychiatric advocacy and education contributions.

References

Castellano S, Torrent C, Petralia MC, et al. Clinical and neurocognitive predictors of functional outcome in depressed patients with partial response to treatment: one-year follow-up study. Neuropsychiatr Dis Treat. 2020;16:589-595. doi:10.2147/NDT.S224754
The Lancet Psychiatry. Global Burden of Disease 2021: mental health messages. Lancet Psychiatry. 2024;11(8):573. doi:10.1016/S2215-0366(24)00222-0
Yang H, Gao S, Li J, et al. Remission of symptoms is not equal to functional recovery: psychosocial functioning impairment in major depression. Front Psychiatry. 2022;13:915689. doi:10.3389/fpsyt.2022.915689
World Health Organization. Programme on Mental Health: WHOQOL User Manual. World Health Organization; 2012.
IsHak WW, Greenberg JM, Balayan K, et al. Quality of life: the ultimate outcome measure of interventions in major depressive disorder. Harv Rev Psychiatry. 2011;19(5):229-239. doi:10.3109/10673229.2011.614099
IsHak WW, Mirocha J, James D, et al. Quality of life in major depressive disorder before/after multiple steps of treatment and one-year follow-up. Acta Psychiatr Scand. 2015;131(1):51-60. doi:10.1111/acps.12301
Newson JJ, Parameshwaran D, Thiagarajan TC. PHQ-9, Life Impact, and Breadth of Symptomatic Experience. Sapien Labs; 2023.
American Psychiatric Association. Practice Guideline for the Treatment of Patients With Major Depressive Disorder. 3rd ed. American Psychiatric Association; 2010.   
McKnight PE, Kashdan TB. The importance of functional impairment to mental health outcomes: a case for reassessing our goals in depression treatment research. Clin Psychol Rev. 2009;29(3):243-259. doi:10.1016/j.cpr.2009.01.005
Turner-Bowker D, Hogue SJ. Short Form 12 Health Survey (SF-12). In: Michalos AC (ed). Encyclopedia of Quality of Life and Well-Being Research. Springer; 2014. doi:10.1007/978-94-007-0753-5_2698

Vilagut G, Forero CG, Pinto-Meza A, et al. The mental component of the Short-Form 12 Health Survey (SF-12) as a measure of depressive disorders in the general population: results with three alternative scoring methods. Value Health. 2013;16(4):564-573. doi:10.1016/j.jval.2013.01.006
Shah CH, Brown JD. Reliability and validity of the Short-Form 12 Item Version 2 (SF-12v2) health-related quality of life survey and disutilities associated with relevant conditions in the U.S. older adult population. J Clin Med. 2020;9(3):661. doi:10.3390/jcm9030661
Ware JE, Kosinski M, Keller SD. SF-12: How to Score the SF-12 Physical and Mental Health Summary Scales. 2nd ed. The Health Institute, New England Medical Center; 1995.
Hunt SM, McKenna SP. The QLDS: a scale for the measurement of quality of life in depression. Health Policy. 1992;22(3):307-319. doi:10.1016/0168-8510(92)90004-u

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