Summary
Introduction
There is evidence supporting an association between depression and anxiety in patients with chronic disease. Spasmodic dysphonia (SD) is a chronic, incurable, and disabling voice disorder. Reported rates of depression and anxiety in SD range from 7.1% to 72%, with a maximum number of 18 patients. The goal of this study was to define the coprevalence of depression and anxiety with SD.
Materials and Methods
A single-institution case-control study was performed from May to July 2010. Consecutive patients with SD and benign voice disorders were enrolled prospectively. On enrollment, patients were asked to fill out a questionnaire that reviewed the duration of the voice disorder and personal history of anxiety and depression, including current and lifetime diagnosis.
Results
One hundred forty-six controls with benign voice disorders and 128 patients with SD were enrolled. Patients with SD were no more likely to be diagnosed with depression or anxiety than those of the control group (odds ratio [OR] = 0.985, 95% confidence interval [CI] = 0.59–1.63; and OR = 1.314; 95% CI 0.75–2.3, respectively). Additionally, duration of disease was a risk factor for depression in both the SD group and the control group, and the association was not significantly different between groups.
Conclusion
Patients with SD were no more likely to have depression or anxiety than those with other voice disorders. It is important for otolaryngologists to be aware of the increased rates of depression in patients diagnosed with chronic diseases, including voice disorders, and to refer to a psychiatrist when appropriate.
Keywords: Anxiety, Depression, Spasmodic dysphonia
INTRODUCTION
Spasmodic dysphonia (SD) is a rare phonatory disorder of unknown pathogenesis. It is a type of dystonia that affects the laryngeal muscles causing involuntary and sustained muscle contractions. SD is a chronic, incurable, and disabling voice disorder.1 Patients suffer from voice breaks and a strained/strangulated voice. Other actions such as swallowing and singing are often unimpeded. Current treatments provide only temporary relief of symptoms. Approximately 50,000 individuals in North America have SD. However, no reliable validated screening tool exists, so SD is likely underdiagnosed. SD typically presents in the fifth decade of life with a female predominance of 2.6:1.2
SD is a chronic neurological condition for which there is no cure. There is evidence supporting an association between depression and anxiety in patients with chronic disease,3–10 including heart disease, osteoporosis,11 and chronic obstructive pulmonary disease.12 Although the rates of depression and anxiety vary with the type of disease, the lifetime risk of developing depression that necessitates assistance from a health care professional is approximately 20% across all chronic disease,13 as compared with approximately 10% in healthy individuals.14 It has also been shown that the longer a patient endures a chronic disease, the higher the likelihood the person has of developing depression.12
Data are limited concerning the rate of comorbid depression and anxiety in patients with SD. In the United States, reported rates of comorbid depression and anxiety in SD range from 7.1% to 72%, with a maximum number of 18 patients.15–17 Many of the studies finding an association between psychiatric disease and SD were written when SD was thought to be a psychogenic disorder caused by neurosis. These early articles attempted to prove that stress, depression, and anxiety were the precipitating factors in developing SD, not the consequence of the disease.17–20 Although SD has now been proven to be a neurological disease, the coincidence of depression and anxiety cannot be ignored. To date, there are no studies correlating the duration of SD with the prevalence of comorbid depression and anxiety nor are there accurate data of the coprevalence of SD with depression and anxiety.
MATERIALS AND METHODS
The study used a case-control design. Between May and July 2010, 130 consecutive patients with SD and 157 consecutive patients with benign voice disorders were enrolled prospectively from a referral academic laryngology practice. Both new and returning patients were included. Emory University Institutional Review Board approval was obtained. Volunteers signed a written consent form before study participation. All patients were diagnosed with primary SD after a comprehensive speech and voice evaluation, including standard vocal tasks and videolaryngostroboscopy by both a fellowship-trained laryngologist and a speech-language pathologist who specialized in voice disorders and had extensive experience in voice disorder assessment and management.
Exclusion criteria for the patients with benign voice disorders included voice disorder because of malignancy, voice disorder because of a neurological condition, or chief complaint other than voice disorder. Exclusion criteria for the patients with SD included generalized dystonia.
On enrollment, patients were asked to fill out a questionnaire that reviewed the duration of the voice disorder and personal history of anxiety and depression, including current treatment and lifetime diagnosis. Our goal was to look for an association between anxiety and depression in patients with SD as compared with patients with benign voice disorders in a treatment-seeking population from the same clinic.
To compare the two groups, t tests for the quantitative outcome variables and Pearson chi-square tests for the binary and categorical variables were used. If any expected table entries were less than 5, then Fisher exact test instead of the Pearson chi-square test was used. All tests were two sided, and P values less than 0.05 were regarded as significant.
RESULTS
Two hundred eighty-five patients were enrolled. Of these, 11 patients were excluded, that is, three patients with a diagnosis other than a voice disorder, three patients with generalized dystonia, three patients with a voice disorder secondary to a different neurological condition, one patient with a voice disorder secondary to a malignancy, and one patient with a missing diagnosis. Two hundred seventy-four participants, aged 18–82 years, were included. Of the included patients, 146 were in the control group and 128 were diagnosed with SD (Table 1 for the individual diagnoses within the control group). Ninety-five percent of patients with SD had adductor type, 4% had abductor type, and 1% had atypical SD. Additional clinical and demographic information are contained in Table 2.
TABLE 1.
Individual Diagnoses and Percentage With Depression and Anxiety (n) Within the Control Group
| Diagnosis Within the Benign Voice Disorders Control Group |
n | Patients With Anxiety, % (n) | Patients With Depression, % (n) |
|---|---|---|---|
| Laryngitis | 10 | 20 (2) | 50 (5) |
| Allergies | 1 | 0 (0) | 0 (0) |
| Vocal fold keratosis | 2 | 50 (1) | 50 (1) |
| Vocal ford dysplasia | 1 | 0 (0) | 100 (1) |
| Vocal fold atrophy | 6 | 0 (0) | 50 (3) |
| Vocal fold cyst | 3 | 33 (1) | 0 (0) |
| Vocal fold granuloma | 4 | 0 (0) | 0 (0) |
| Vocal fold nodules | 2 | 0 (0) | 100 (2) |
| Vocal fold paralysis | 45 | 15 (7) | 29 (13) |
| Vocal fold paresis | 5 | 0 (0) | 0 (0) |
| Vocal fold polyp | 7 | 29 (2) | 29 (2) |
| Vocal fold scarring | 3 | 0 (0) | 33 (1) |
| Vocal fold hemorrhage | 1 | 0 (0) | 0 (0) |
| Glottic scar | 2 | 50 (1) | 50 (1) |
| Glottic stenosis | 1 | 0 (0) | 0 (0) |
| Laryngopharyngeal reflux | 3 | 0 (0) | 33 (1) |
| Laryngeal papillomatosis | 8 | 13 (1) | 13 (1) |
| Laryngeal sarcoidosis | 2 | 0 (0) | 0 (0) |
| Laryngeal edema | 1 | 0 (0) | 0 (0) |
| Laryngeal spasm | 3 | 33 (1) | 66 (2) |
| Laryngospasm | 1 | 100 (1) | 0 (0) |
| Muscle tension dysphonia | 14 | 29 (4) | 36 (5) |
| Paradoxical vocal fold movement | 3 | 33 (1) | 66 (2) |
| Phonotrauma | 4 | 50 (2) | 25 (1) |
| Postintubation phonatory insufficiency | 2 | 50 (1) | 50 (1) |
| Reinke’s edema | 1 | 0 (0) | 0 (0) |
| Sulcus vocalis | 1 | 0 (0) | 0 (0) |
| Chronic cough | 1 | 0 (0) | 0 (0) |
| Dysfluency | 1 | 100 (1) | 100 (1) |
| Dysphonia | 2 | 0 (0) | 0 (0) |
TABLE 2.
Clinical and Demographic Characteristics
| Characteristic | Controls (n = 146) |
SD (n = 128) |
P Value |
|---|---|---|---|
| Gender | |||
| Female | 96 (66) | 101 (79) | 0.02 |
| Male | 50 (34) | 27 (21) | |
| Race | |||
| White/Caucasian | 102 (70) | 103 (80) | 0.13 |
| Black/African American |
36 (25) | 20 (16) | |
| Other | 8 (5) | 5 (4) | |
| Age, y | 55.0 ± 14.9 | 59.3 ± 12.4 | 0.009 |
| Duration of disease, y | 7.4 ± 12.7 | 17.4 ± 13.6 | <0.001 |
| Depression | 42 (29) | 36 (28) | 0.91 |
| Anxiety | 28 (19) | 32 (25) | 0.25 |
| Depression and/or anxiety |
51 (35) | 52 (41) | 0.33 |
Values are represented as mean ± standard deviation or frequency (%).
An independent samples test indicated that patients with SD (mean = 59.3, standard deviation = ±12.4) were significantly older than controls (mean 55.0, standard deviation =±14.9), t(272) = 2.60, P = 0.009. Additionally, the duration of illness in patients with SD (mean = 17.4, standard deviation =±13.6 years) was significantly longer than that of illness in controls (mean = 7.4, standard deviation =±12.7 years), t(271) = 271, P = 0.001 (Table 2).
Chi-square analyses were conducted to determine whether there were significant differences among demographic and clinical categories. Analyses indicated that the proportion of women in the SD group (79%) was significantly higher than that of women in the control group (66%), P = 0.02. There was no significant difference in the proportion = of patients with depression in the SD group (28%) and the control group (29%), P > 0.05. Neither was there a difference in the proportion of patients with anxiety in the SD group (25%) and the control group (19%), P > 0.05 (Table 3).
TABLE 3.
Relationship Between Depression and Duration of Disease in SD Patients and Controls
| Duration of Disease, y | Proportion of Patients Who Are Depressed |
Test of Whether the Association Between Depression and Duration of Disease Differed Between SD Patients and Controls* |
|
|---|---|---|---|
| Controls | SD | ||
| <5 | 24/105 (23%) | 2/18 (11%) | P = 0.21 |
| 5–10 | 5/10 (50%) | 6/26 (23%) | |
| >10 | 13/31 (42%) | 28/83 (34%) | |
Based on a logistic regression model in which depression was the outcome and an interaction effect was entered between SD and duration of disease (coded as a continuous variable). Results were adjusted for age and gender.
A logistic regression analysis was performed to determine if there was a significant difference in the association between duration of illness and depression in patients with SD and controls. Depression was the outcome, and an interaction effect was entered between SD and controls and duration of disease (coded as a continuous variable). Analysis was adjusted for age and gender. There was no evidence that the association between depression and duration of illness differed between patients with SD and controls, P = 0.21 (Table 3).
As there was no significant difference in the association of duration of illness and depression between patients with SD and controls, the groups were combined to determine if there was a significant association between duration of illness and depression in all patients with voice disorders. This was determined using a logistic regression model in which depression was the outcome and duration of disease (coded as a continuous variable) was entered as an explanatory variable. Results were adjusted for age and gender. Analyses indicated that duration of disease was positively associated with depression, P = 0.05 (Table 4).
TABLE 4.
Relationship Between Depression and Duration of Disease, Where the SD Group and Controls are Pooled
| Duration of Disease, y |
Not Depressed, n (%) |
Depressed, n (%) |
Test of Association Between Depression and Duration of Disease* |
|---|---|---|---|
| <5 (n = 123) | 97 (79) | 26 (21) | P = 0.05 |
| 5–10 (n = 36) | 25 (69) | 11 (31) | |
| >10 (n = 114) | 73 (64) | 41 (36) |
Based on a logistic regression model in which depression was the outcome and duration of disease (coded as a continuous variable) was entered as an explanatory variable. Results were adjusted for age and gender.
A logistic regression analysis was then performed to determine if there was a significant difference in the association between anxiety and duration of disease in patients with SD and controls. Anxiety was the outcome, and an interaction effect was entered between SD and controls and duration of disease. Analysis was adjusted for age and gender. There was no evidence that the association between anxiety and duration of disease differed between patients with SD and controls, P = 0.76 (Table 5).
TABLE 5.
Relationship Between Anxiety and Duration of Disease in SD Patients and Controls
| Duration of Disease, y | Proportion of Patients With Anxiety |
Test of Whether the Association Between Anxiety and Duration of Disease Differed Between SD Patients and Controls* |
|
|---|---|---|---|
| Controls | SD | ||
| <5 | 20/105 (19%) | 5/18 (28%) | P = 0.76 |
| 5–10 | 2/10 (20%) | 9/26 (35%) | |
| >10 | 6/31 (19%) | 18/83 (22%) | |
Based on a logistic regression model in which anxiety was the outcome and an interaction effect was entered between SD and duration of disease (coded as a continuous variable). Results were adjusted for age and gender.
As there was no significant difference in the association of anxiety and duration of disease between patients with SD and controls, the groups were combined to determine if there was an association between anxiety and duration of illness in all patients with voice disorders. This was determined using a logistic regression model in which anxiety was the outcome and duration of disease (coded as a continuous variable) was entered as an explanatory variable. Results were adjusted for age and gender. There was no evidence of an association between anxiety and duration of disease in patients with voice disorders, P = 0.99 (Table 6).
TABLE 6.
Relationship Between Anxiety and Duration of Disease, Where the SD Group and Controls are Pooled
| Duration of Disease, y |
Not Anxious, n (%) |
Anxious, n (%) |
Test of Association Between Anxiety and Duration of Disease* |
|---|---|---|---|
| <5 (n = 123) | 98 (80) | 25 (20) | P = 0.99 |
| 5–10 (n = 36) | 25 (69) | 11 (31) | |
| >10 (n = 114) | 90 (79) | 24 (21) |
Based on a logistic regression model in which anxiety was the outcome and duration of disease (coded as a continuous variable) was entered as an explanatory variable. Results were adjusted for age and gender.
A logistic regression analysis was used to determine if there was a significant difference in the association between anxiety and depression in patients with SD and controls. Depression was the outcome, and an interaction effect was entered between SD and controls and anxiety. Results were adjusted for duration of disease, age, and gender. There was no evidence that the association of anxiety and depression differed between patients with SD and controls, P = 0.24 (Table 7).
TABLE 7.
Relationship Between Depression and Anxiety in SD Patients and Controls
| Anxiety | Proportion of Patients Who Are Depressed |
Test of Whether the Association Between Depression and Anxiety Differed Between SD Patients and Controls* |
|
|---|---|---|---|
| Controls | SD | ||
| Yes | 19/28 (68%) | 16/32 (50%) | P = 0.24 |
| No | 23/118 (19%) | 20/96 (21%) | |
Based on a logistic regression model in which depression was the outcome and an interaction effect was entered between SD and anxiety. Results were adjusted for duration of disease, age, and gender.
As there was no significant difference in the association between anxiety and depression in patients with SD and controls, the groups were combined to determine if there was a significant difference an association between anxiety and depression in all patients with voice disorders. This was determined by using a logistic regression model in which depression was the outcome and anxiety was entered as an explanatory variable. Results were adjusted for duration of illness, age, and gender. Analyses demonstrated that there was an association between anxiety and depression in patients with voice disorders, P < 0.001 (Table 8).
TABLE 8.
Relationship Between Depression and Anxiety, Where the SD Group and Controls are Pooled
| Anxiety | Not Depressed, n (%) |
Depressed, n (%) |
Test of Association Between Depression and Anxiety* |
|---|---|---|---|
| Yes (n = 60) | 25 (42) | 35 (58) | P < 0.001 |
| No (n = 214) | 171 (80) | 43 (20) |
Based on a logistic regression model in which depression was the outcome and anxiety was entered as an explanatory variable. Results were adjusted for duration of disease, age, and gender.
DISCUSSION
This study demonstrates that patients with SD are no more likely than voice disorder controls to be diagnosed with anxiety or depression. Additionally, the proportion of patients with depression in both the SD and the control groups (28.3% and 28.7%, respectively) is higher than the average rate of depression in the United States (10%) and more closely approximates the average rate of depression in chronic disease (20%). Additionally, the proportion of patients with previously diagnosed anxiety in both the SD and control groups (25.2% and 19.2%, respectively) was higher than the rate of anxiety in the general population (14%).
It has been previously reported in several large studies that duration of chronic disease is associated with the development of depression. In this study, duration of disease was associated with depression in both the control and the SD groups, with no significant difference between groups (P = 0.21). Voice disorders are often socially and functionally debilitating, interfering with the basic ability to communicate. Additionally, many voice disorders, including SD, are chronic conditions with no cure and often require long-term follow-up with voice specialists. It is important for otolaryngologists to be aware of the increased risk of developing depression when treating patients with any chronic voice disorder.
The proportion of patients with comorbid anxiety was not significantly higher in the SD group than the control group (P = 0.25). This is particularly notable becausen of the history of SD. Before SD was determined to be a neurological condition, it was thought to be a psychogenic condition precipitated by stress, anxiety, and neurosis.21 Additionally, an emotional event can precede the onset of SD, so patients are often thought to have more anxiety than other patients. Our study shows that this is not the case. Additionally, population studies in the United States have shown that approximately 50% of patients with mood disorders have comorbid anxiety disorders.22 This holds true for this study population as well, as anxiety was positively associated with depression in both patients with SD (50%) and controls (68%), P < 0.001.
Population-based studies have shown that depressive and anxiety disorders are negatively associated with age and positively associated with femalegender, even when accounting for chronic disease and physical comorbidities.12,23 In our study population, therewas a significant difference in age between patients with SD (mean = 59, standard deviation = ±12 years) and controls (mean = 55, standard deviation =±15 years), P = 0.009. There was also a significant difference in the number of women with SD (79%) compared with voice disorder controls (66%), P = 0.02. Therefore, both age and gender were controlled for in all subsequent analyses.
In 2007, a group in Sweden assessed psychiatric comorbidity in patients with SD as compared with those with recurrent respiratory papillomatosis (RRP).24 The investigators administered several questionnaires, checklists, and assessments to diagnose patients with psychiatric conditions. In their study, 35% of patients with SD were diagnosed with depression or a depression variant and 33% were diagnosed with anxiety. This was not statistically different from those with RRP. Similar to the United States, the prevalence of depression in Sweden is 11% and is positively associated with frequent use of health services, anxiety, and female gender and is negatively associated with age.25 In this study, voice disorder patients were considered to have depression and/or anxiety only if they had sought treatment to be diagnosed with depression and/or anxiety, which is likely why the proportion of those with anxiety and depression is lower. Studies such as the Swedish study that are performed with depression and anxiety scales include patients with any level of depression and anxiety, not necessarily severe enough for patients to seek treatment.
It is important for practitioners who diagnose and treat patients with all voice disorders to be aware that depression and anxiety are more common than previously thought and that psychosocial intervention may be appropriate. Thus, it is important for otolaryngologists to assess for depression and anxiety in patients with voice disorders and refer to a psychiatrist when appropriate.
Limitations/future studies
In this study, only voice disorder patients who had previously been diagnosed with depression or anxiety were included in the subcategory of patients with depression or anxiety. These patients represented a treatment-seeking population, which likely represented patients with more severe disease. Therefore, a limitation of this study is that it likely underestimated the rate of comorbid depression and anxiety because only those patients who had previously been diagnosed with depression and anxiety were included. A future study using validated tools to properly assess for depression and anxiety in patients with SD is warranted.
It has been shown that the more serious the somatic disease is, the more probably it will be accompanied by mood and anxiety symptoms.12 Therefore, a large study that correlates depression and anxiety to symptom severity or frequency of treatment is also warranted. We recommend working with a psychiatrist to develop study design.
CONCLUSION
Patients with SD were no more likely to have depression or anxiety than those with other voice disorders; however, both groups have increased rates of depression and anxiety as compared with the general population. It is important for otolaryngologists to be aware of the increased rates of depression in patients diagnosed with chronic diseases, including voice disorders, and to refer to psychiatrist when needed.
Acknowledgments
Funding support for this project has been provided by The Dystonia Coalition, which is part of the National Institutes of Health (NIH) Rare Disease Clinical Research Network through the NIH Office of Rare Diseases Research (NS067501) and the National Institute of Neurological Disorders and Stroke.
This project is also supported in part by PHS Grant Jul1RR125008, KL2 RR025009, or TL1 RR025010 from the Clinical and Translational Science Award program, National Center for Research Resources, NIH.
The views expressed in written materials or publications do not necessarily reflect the official policies of the Department of Health and Human Services nor does mention by trade names, commercial practices, or organizations imply endorsement by the U.S. Government.
Footnotes
Conflict of interest: none.
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