Symptoms of Depression and Anxiety Assessed By the SF-36 Questionnaire in Patients with AL Amyloidosis

Background: New advances in treatment have improved survival of patients with AL amyloidosis, but research examining the prevalence and significance of anxiety and depression in these patients is limited. Although the association between cardiac involvement and a poorer prognosis has been well established, only early evidence demonstrates influence of cardiac involvement on anxiety and depression. This study examined the prevalence of symptoms of depression and anxiety in patients with AL amyloidosis and whether these symptoms were associated with cardiac involvement and other demographic factors.

Methods: This is a retrospective review of cardiac involvement and the Medical Outcomes Study 36-item Short Form General Health Survey (SF-36) of 1414 patients with AL amyloidosis at initial evaluation in the Amyloidosis Center at Boston University School of Medicine and Boston Medical Center from July 1993 to May 2013. Prevalence of self-reported symptoms of depression, symptoms of anxiety, and role limitations due to emotional problems (RE) were derived from the SF-36 questionnaire. Patients were said to have endorsed symptoms of anxiety and depression if they reported a positive score on a 6 point Likert scale to at least one question pertaining to depression and anxiety symptoms in the SF-36 (e.g., "Have you been a very nervous person?"). RE was traditionally scored as a subscale of the SF-36 by averaging the values of the responses. Out of total of 1414 patients, patients with unknown cardiac involvement (n=6) and those who did not answer a single question from each category of interest in the SF-36 (depression n=32; anxiety n=37; RE n=1) were excluded from their respective analysis. A stepwise logistic regression was performed to examine whether self-reported symptoms of depression and anxiety, and RE were associated with cardiac involvement and other demographic factors including gender, age, race, marital status, alcohol consumption, and current smoking status.

Results: Of the patients included in the analyses: 659 (46.6%) had cardiac involvement, 523 (38.0%) endorsed depression, 673 (48.6%) endorsed anxiety, and 707 (51.1%) had RE. Patients with cardiac involvement (odds ratio [OR] = 1.31, 95% confidence interval [CI] = 1.05-1.63) and smokers (OR=1.27, CI=1.01-1.59) had significantly greater odds of endorsing symptoms of depression. Men (OR=0.73, CI=0.58-0.90) had significantly lower odds of reporting symptoms of anxiety, while patients with cardiac involvement (OR=1.26, CI=1.02-1.56) and smokers (OR=1.30, CI=1.04-1.62) had significantly increased odds of reporting symptoms of anxiety. Age ≥ 65 years was the only significant predictor of RE (OR=1.44, CI=1.16-1.79).

Conclusions: Depression and anxiety symptoms are common among patients with AL amyloidosis and also may have an adverse impact on daily functioning. After controlling for relevant demographic factors, patients with AL amyloidosis and cardiac involvement have greater odds of reporting symptoms of depression and anxiety. Limitations include extrapolating measures of depression and anxiety from a quality of life assessment and not exploring the impact of clinical severity of disease or comorbidities on these symptoms. Further research is needed to study the clinical impact on the treatment and well-being from these experiences of depression and anxiety commonly faced in AL amyloidosis. Indeed, these symptoms of clinical illness - depression and anxiety - can be significant comorbidities that require further attention as part of overall patient care.