The neurophysiological model of tinnitus purports that “the auditory system provides the source of a signal, tinnitus, which, through inappropriately created functional connections, causes activation of the limbic and autonomic nervous systems, resulting in annoyance and distress (Neurosci Res. 1990; 8:221 http://bit.ly/2b5qBqx).” The limbic system regulates mood, emotion, and motivation, and its dysfunction has been shown to result in various neuropsychiatric disorders that have demonstrated positive relationships with tinnitus (Neural Plast. 2014;2014:817852 http://bit.ly/2b5rEqy). Jastreboff and Hazell stated that tinnitus-related negative activity of the limbic and autonomic nervous systems may lead to depression (Cambridge University Press, 2004http://bit.ly/2b5BusC).
Benton reported that tinnitus patients with coexisting mental health disorders demonstrated greater perceived tinnitus severity and distress than those without co-existing mental health disorders (AAA meeting, 2010). Subjects were 115 veterans seen for a primary complaint of tinnitus. Eighty-two subjects (71.3%) had coexisting mental health diagnoses; the remaining 33 subjects (29.7%) did not. Suicidal ideation (any thought of engaging in suicide-related behavior) was explored among these subjects via question 24 in the Tinnitus Reaction Questionnaire (TRQ) (J Speech Hear Res. 1991;34:197 http://bit.ly/2b5ECES). Forty-nine percent of the tinnitus subjects with diagnosed mental health disorders and 12 percent of tinnitus subjects without diagnosed mental health disorders reported that their tinnitus had led them to think about suicide. More recently, Fox-Thomas reported that only 32 of her 200 subjects (16%) reported suicidal ideation on question 24 in the TRQ (Hearing Journal. 2016;6910 http://bit.ly/2csCZ4w). However, Fox-Thomas did not analyze the mental health status of her subjects.
Progressive Tinnitus Management (PTM) is the recommended tinnitus management strategy for U.S. veterans and emphasizes an interdisciplinary-team approach to tinnitus management between audiologists and psychologists (J Rehabil Res Dev. 2005;42[4 Suppl 2]95 http://bit.ly/2al3dbr). PTM is a five-level hierarchical process for the identification and provision of the least intensive tinnitus management sufficient to provide the patient adequate relief. The participation of both audiologists and psychologists in PTM testifies to the importance of mental health services for tinnitus patients, but there remains a need for more information about the relationship between tinnitus and mental health. Folmer and colleagues termed the relationship as “bi-directional”–tinnitus distress can affect mental health symptoms and mental health symptoms can affect tinnitus distress (Int Tinnitus J. 2008;14:127 http://bit.ly/2c1KzC8).
We collected data from the VA Computerized Patient Record System for a 21-month period. All subjects were referred to the Atlanta VA Audiology Clinic for a primary complaint of tinnitus and had completed the first three levels of PTM (Triage, Audiological Evaluation, and Group Education), along with the associated actions for each level.
Subject records were reviewed for the presence or absence of both hearing loss and mental health diagnoses, for subjects’ scores on the Patient Health Questionnaire (PHQ9) and for their scores on a nine-item screening measure for depression, for mental health screening purposes (J Gen Intern Med. 2001;16:606 http://bit.ly/2al70W7). Subjects’ records were also reviewed for measures of perceived tinnitus severity, including scores on the Tinnitus Functional Index (TFI) and TRQ, estimates of tinnitus awareness (the percentage of waking hours the subject heard or was aware of his or her tinnitus), and disturbance (the percentage of time the subject was aware of and felt truly disturbed by his or her tinnitus) (Ear Hear. 2012;33:153 http://bit.ly/2algzo6). The awareness estimate was then multiplied by the disturbance estimate to provide the Total Disturbance value (the percentage of overall waking hours the subject was truly disturbed by his or her tinnitus). Data were analyzed to evaluate any relationships between mental health status and perceived tinnitus severity, and between specific diagnoses and perceived mental health severity.
Of the 323 subjects identified, 223 (61%) had been diagnosed with at least one mental health disorder (YesMH group) while the remaining 100 (39%) had no diagnosed mental health disorders (NoMH group). Table 1 provides additional demographic data for the two groups. Table 2 provides the specific mental health diagnoses for the YesMH subjects. Nearly half of the YesMH subjects (47%) had two or more mental health diagnoses.To facilitate the inclusion of subjects’ age as a possible factor in statistical analyses, subjects were categorized into three age groups as shown in Table 3.
A 3 x 2 x 2 ANOVA was completed with independent factors: Age Group (Younger, Middle, Older), Hearing Aid Status (Yes/No), and Mental Health Status (Yes/No) and the dependent factor TRQ Score (n=323). Only the Mental Health Status x Age Group interaction was significant (p=.017). Holm-Sidak follow-up comparisons revealed that there were significant differences in mean TRQ scores between the YesMH and NoMH groups for both the Younger (Cohen's d=0.88) and Older (Cohen's d=0.57) subject groups. Also, the mean TRQ score for Middle-Age NoMH subjects was significantly greater than that for Older-Age NoMH subjects (Cohen's d=0.59). Figure 1 presents the mean TRQ scores for the significant comparisons.To further explore the relationship between mental health status and perceived tinnitus severity, a series of simple correlations were performed between PHQ9 scores and TRQ scores (n=82; r=.785, p<.001), PHQ9 scores and TFI scores (n=80; r=.699, p<.001), and PHQ9 scores and Total Disturbance percentages (n=82; r=.586, p<.001). The strength of the relationships is shown in scatter plots (Fig. 2). Jandel SigmaPlot 11.2 (Systat Software, San Jose, CA) was utilized to perform a multiple linear regression (n=82) with the dependent factor PHQ9 Score and independent factors TRQ Score and Age in Years: PHQ9=4.167 (0.0817*Age in Years) + (0.244*TRQ Score). Jandel SigmaPlot 11.2 indicated that not all of the independent variables were necessary: the TRQ Score alone appeared to account for the ability to predict PHQ9 (p< 0.05).
Use of the PHQ9 for mental health screening of tinnitus patients was evaluated in 82 subjects, 54 of whom (66%) had been diagnosed with MH disorders and 28 of whom (34%) had no MH diagnoses. Interestingly, Fisher's exact test revealed that the relationship between MH group and PHQ9 score categories was not significant (p=1.0). This is demonstrated in Table 4, which reveals that over half of the NoMH patients’ PHQ9 scores placed them in the moderate-to-severe depression categories, suggesting that tinnitus patients without diagnosed mental health disorders are at risk for depression.
Three subgroups of YesMH subjects were compared based on specific mental health diagnoses: Depression Only (n=46), PTSD Only (n=50), and Depression + PTSD (n=36). No other specific mental health diagnoses were present in a large enough number of subjects for comparison purposes. Two three-way ANOVAs (Age x MH Diagnosis x Aided Status) revealed that there were no significant differences (p> .05) among mean TRQ scores nor among mean Total Disturbance percentages for the three MH subgroups, suggesting that the specific mental health disorder has no significant impact on reported tinnitus-related distress (Fig. 5).
These findings confirm that there is a strong relationship between mental health status and perceived tinnitus severity. The findings also emphasize the importance of routine mental health screening for tinnitus patients and that of including mental health professionals as members of the tinnitus management team. TRQ scores, TFI scores, and Total Disturbance values each demonstrated a strong positive correlation to PHQ9 scores. Over half of the tinnitus subjects with no previously diagnosed mental health disorders scored in the moderate-to-severe depression category on the PHQ9. Audiologists must acknowledge and understand the impact of coexisting mental health disorders on perceived tinnitus severity as well as the likely impact of such disorders on tinnitus management strategies and outcomes.