International Journal of Psychiatry in Clinical Practice, 2006; 10(Suppl 1): 27 /30

ORIGINAL ARTICLE

Quality of life in depression and anxiety: does it matter?

KOEN DEMYTTENAERE

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Department of Adult Psychiatry, University Hospital Gasthuisberg, Leuven, Belgium

Abstract Quality of life (QoL) is an assessment going beyond symptom control that investigates positive effects, life satisfaction, wellbeing, impairment and functioning of a patient. Compared with patients with other common medical disorders, patients with mood (and to a lesser extent) anxiety disorders exhibit an impairment that pervades all dimensions of the QoL scale. There are function- and needs-based approaches to QoL measurement. The availability of numerous QoL scales also prompt careful selection, as different scales stem from varying notions of QoL. Although the effect size of pharmacological treatment on QoL scales is usually smaller than on symptom scales, it is nevertheless clinically significant. Newer antidepressants, such as escitalopram, have been shown to improve QoL in patients with depression and anxiety disorders. Increased assessment of QoL should be encouraged in future trials, to improve the understanding of treatment impact on overall well-being, in patients with depression and anxiety disorders.

Key Words: Quality of life, depression, anxiety disorders

What is a ‘‘good enough’’ outcome? The objective assessment of depression relies heavily on well-established scales that often inform physicians on whether the depressed patient presents with less negative mood (is ‘‘less bad’’), instead of presenting with more positive mood (‘‘good enough’’). A lot of psychological studies, however, showed that negative and positive effects are not highly correlated, suggesting that they represent two partially different dimensions of affect. At symptom level, patients are measured by their response rate to treatment and their time in remission. However, patients who are in full remission do not seem to be comparable with those who have never been depressed. This has been called the ‘‘scar’’ hypothesis: there may be chemical and cognitive changes following a major depressive episode. Recent research shows that there could well be cognitive, chemical and structural changes (decreased hippocampal volume) after recurrent episodes of major depression. Another example is the dormant cognitive bias in depressed patients who have completely recovered. Completely remitted patients show the same scores on a symptom scale, as well as on a dysfunctional attitude scale, as healthy controls without a history of depression, but in a negative mood induction experiment, both do show some increase in

symptom level, but only previously depressed patients show an increase in dysfunctional attitudes [1]. In order to assess more ecologically valid outcomes in depressed patients, physicians must examine beyond the symptom level to include an assessment of: . positive affect and well-being . functioning such as impairment and disability . QoL.

Comparing QoL: Mood versus medical disorders Besides this ‘‘going beyond symptoms assessment’’, QoL scales are also useful tools to compare the degree of burden and impairment of various illnesses, and may be a valuable utility when prioritizing resource allocations. Indeed, most care providers have to allocate limited budgets to different somatic and psychiatric disorders and prioritization should be made on direct and indirect costs of the different disorders, on mortality and morbidity, and on their treatability. Therefore, generic scales are needed, to be able to compare the ‘‘quality of life’’ in patients with different disorders, before and after treatment. When mood disorders were compared

Correspondence: Koen Demyttenaere, Head of Department of Adult Psychiatry, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. Tel: /32 1634 8701. Fax: /32 1634 8700. E-mail: [email protected]

ISSN 1365-1501 print/ISSN 1471-1788 online # 2006 Taylor & Francis DOI: 10.1080/13651500600552511

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with common medical disorders on the healthrelated quality of life (HR-QoL) SF20 scale, all domains (the physical as well as the psychological component) of HR-QoL were affected [2]. Physical impairment in mood disorders was similar to that in cancer. Mood disorders severely impair mental and physical quality of life, while anxiety disorders mainly affect mental health.

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Approaches to measuring QoL Broadly, there are two approaches to measuring QoL. In the function-based approach, such as the SF36 and Sheehan Disability Scale SDS scale, the assumption is made that there is an optimal level of functioning to which all human beings should aspire. For instance, one should be able to walk 100 metres. The definition of functioning encompasses occupational, social, family, physical and psychological aspects. One criticism is that when comparing an older with a younger person, this approach results in labelling the older person as having a lower QoL, due to the presence of age-related limitations. Indeed, it has been shown that even heavily ‘‘physically impaired subjects’’ (e.g., wheelchair patients) can have a high quality of life or life satisfaction. In the needs-based approach, it is believed that life gains its quality from the ability and capacity of individuals to satisfy their needs, either inborn or learned during socialization processes. This includes the need for companionship, love, conversation, pleasure, self-care and nutrition. Taking the example mentioned above, in a needs-based approach, being able to walk is important only in the way it facilitates basic needs. This approach takes into consideration the possible shift in a person’s internal norm or standards of QoL that may be induced by extreme experiences or physical limitations. QoL in depression and anxiety disorders It is of utmost importance that depressed patients are treated to full recovery because the presence of residual depressive symptoms imposes a negative predictive effect on rapid relapse [3]. But even in patients in full remission, psychosocial impairment, as assessed with QoL scales such as SDS, is a powerful predictor of recurrence, even after correcting for residual symptoms [4]. Compared with symptom scales such as the Montgomery-Asberg Depression Scale (MADRS) and the Hamilton Depression Scale (HAM-D), the change in effect in QoL scales, such as the Quality of Life Satisfaction Scale Questionnaire (Q-LES-Q), is usually smaller, because QoL measured in these scales is more subjective and influenced by external circumstances. In a study by Bech et al. [5] investigating the dose-response relationship of escitalopram compared with citalopram in depression,

the effect size of escitalopram 20 mg was significantly superior to that of citalopram 40 mg across two symptom scales and one QoL scale, indicating that escitalopram not only improves the functioning and symptoms of depression, but also the QoL, of depressed patients. Anxiety disorders adversely interfere with daily functioning and should not be considered as mild conditions. Patients with social anxiety disorder (SAD) have significant impairment in social and occupational functioning, as measured by SDS [6]. Treatment with SSRIs clinically improves disability in all aspects of SDS components [6]. It is important that patients with an anxiety disorder receive a sufficient duration of treatment, as treatment response is typically slow, and further improvements may still be observed between 12 and 24 weeks of treatment (Figure 1) [6]. In generalized anxiety disorder (GAD), a similar trend of smaller but significant effect was observed in escitalopram-treated patients on the QoL scale that was not detected with the symptom scale [7]. Escitalopram improves most components of the Q-LES-Q subscales (Figure 2) [8]. Considerations in selecting QoL scales There are more than 160 QoL scales available and patients often complete questionnaires that do not reflect their concerns. The choice of QoL questionnaires / generic or disease-specific, medical or mediational model, observer-rated or self-rated / lies with the physician and the specific outcome measures needed to be derived from the questionnaire. The medical understanding of QoL is the balance between symptom improvement and the potential of side effects with any given treatment. In a mediational model, however, it is proposed that intermediate factors link the disorder and the quality of life in a patient. Mechanic et al. [9] examined the correlation between the change in QoL and several intermediate

Figure 1. Mean change from baseline in SDS work score among placebo (PBO), paroxetine (PAR) and escitalopram (ESC) groups at weeks 12 and 24 [6]. **P B/0.01 versus placebo; ***P B/0.001 versus placebo.

Quality of life in depression and anxiety

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rence. Careful use of QoL scales should help us in focusing on beyond symptom issues important for our patients, such as self-esteem, being understood and being of use. Future clinical trials of psychopharmacological treatments should focus more on QoL assessment as part of outcome measures, as QoL is, to a significant degree, independent of symptom control, response and remission rates. Key points

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Figure 2. Differences in efficacy of escitalopram from placebo at week 8 on Q-LES-Q (15/1 items) in a pooled GAD analysis, **P 5/0.01, ***P 5/0.001 [8].

factors using the Lehman QoL scale. The study found that medication side effects did not contribute greatly to QoL. Improvement in social relations, selfesteem and personal control correlated better with QoL than medication side effects [9]. In addition, the patient’s attribution of problems had an influence on the QoL. For the same severity of mental disorder, greater attribution of the disorder to a physical cause resulted in a higher QoL, while greater attribution to a mental cause resulted in a lower QoL [9]. A mediational model is probably a more accurate measure of QoL than a medical model. The domains of QoL most affected by depression, as measured by Quality of Life Scale 100 (QLS100), were inner experiences of feeling at ease, being pleased with life, sense of fulfilment, being of use and being understood [10]. Work, physical health and mental health were among the least affected domains. There is also debate on whether self- or observerrating of QoL is more appropriate in depression and anxiety disorders. Indeed, there are occasional discrepancies between the physician’s and patient’s view of QoL. In one study, physicians rated major psychotic episodes as having the greatest burden of disease and viewed anxiety disorders as having little impact on QoL [11]. In contrast, patients found that both major depressive disorders and anxiety disorders caused at least a moderate impairment to their lives [6,12]. When QoL was compared between depression and schizophrenia, physicians rated depression as having better QoL scores, while patient ratings revealed the opposite [13]. Negative affectivity as a personality trait explains a significant part of the variance in self-rating HR-QoL [14].

. Quality of life (QoL) assessment goes beyond symptom control and includes positive affect, life satisfaction, well-being, impairment and functioning . Patients with mood and anxiety disorders have impairments in all aspects of QoL . There are a diverse number of QoL measurement scales, including the SF36 and Sheehan Disability Scale (SDS), and use of these should be encouraged in clinical trials . Pharmacological treatments, such as escitalopram, improve QoL in patients with depression and anxiety disorders Statement of interest The author is on the international advisory board/ speaker bureau of Boehringer Ingelheim, Eli Lilly, GlaxoSmithKline, Lundbeck, Organon and Wyeth.

References [1] Teasdale JD, Cox SG. Dysphoria: self-devaluative and affective components in recovered depressed patients and never depressed controls. Psychol Med 2001;31:1311 /6. [2] Spitzer RL, Kroenke K, Linzer M, et al. Health-related quality of life in primary care patients with mental disorders. Results from the PRIME-MD 1000 Study. J Am Med Assoc 1995;274:1511 /7. [3] Judd LL, Akiskal HS, Maser JD, et al. Major depressive disorder: a prospective study of residual subthreshold depressive symptoms as predictor of rapid relapse. J Affect Disord 1998;50:97 /108. [4] Franchini L, Zanardi R, Gasperini M, et al. Two-year maintenance treatment with citalopram, 20 mg, in unipolar subjects with high recurrence rate. J Clin Psychiatry 1999; 60:861 /5. [5] Bech P, Tanghoj P, Cialdella P, et al. Escitalopram doseresponse revisited: an alternative psychometric approach to evaluate clinical effects of escitalopram compared to citalopram and placebo in patients with major depression. Int J Neuropsychopharmacol 2004;7:283 /90. [6] Lader M, Stender K, Burger V, et al. Efficacy and tolerability of escitalopram in 12- and 24-week treatment of social anxiety disorder: randomised, double-blind, placebocontrolled, fixed-dose study. Depress Anxiety 2004;19: 241 /8. [7] Davidson JR, Bose A, Korotzer A, et al. Escitalopram in the treatment of generalized anxiety disorder: Double-blind, placebo controlled, flexible-dose study. Depress Anxiety 2004;19:234 /40. /

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Conclusion QoL is important in depression and anxiety disorders. It is a more patient-focused approach, illustrating the severe impact of mental disorders, like mood and anxiety disorders, and the greater efficacy of available treatments, predicting more long term outcome measures, such as relapse and recur-

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[8] Stein DJ, Andersen HF, Goodman WK. Escitalopram for the treatment of GAD: Efficacy across different subgroups and outcomes. Ann Clin Psychiatry 2005;17:71 /5. [9] Mechanic D, McAlpine D, Rosenfield S, et al. Effects of illness attribution and depression on the quality of life among persons with serious mental illness. Soc Sci Med 1994;39: 155 /64. [10] Carpiniello B, Lai GL, Pariante CM, et al. Symptoms, standards of living and subjective quality of life: A comparative study of schizophrenic and depressed out-patients. Acta Psychiatr Scand 1997;96:235 /41. [11] Sanderson K, Andrews G. Mental disorders and burden of disease: How was disability estimated and is it valid? Aust NZ J Psychiatry 2001;35:668 /76. /

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[12] Kennedy BL, Lin Y, Schwab JJ. Work, social, and family disabilities of subjects with anxiety and depression. South Med J 2002;95:1424 /7. [13] Atkinson M, Zibin S, Chuang H. Characterizing quality of life among patients with chronic mental illness: A critical examination of the self-report methodology. Am J Psychiatry 1997;154:99 /105. [14] Kressin NR, Spiro A, Skinner KM. Negative affectivity and health-related quality of life. Med Care 2000;38: 858 /67. [15] Demyttenaere K, De Fruyt J, Huygens R. Measuring quality of life in depression. Curr Opin Psychiatry 2002; 15:89 /92. /

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Quality of life in depression and anxiety: does it matter?

Quality of life (QoL) is an assessment going beyond symptom control that investigates positive effects, life satisfaction, well-being, impairment and ...
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