Previous research has suggested that a substantial proportion of the population are severely affected by tinnitus, however recent population data are lacking. Furthermore, there is growing evidence that the perception of severity is closely related to personality factors such as neuroticism.
Tinnitus is the perception of sounds in the head or ears, usually defined as a ringing, buzzing or whistling sound. Tinnitus can be objective or subjective. Objective tinnitus is caused by sounds generated by an internal biological activity. However, subjective tinnitus is much more common and results from abnormal neural activities which are not formed by sounds [1]. Subjective tinnitus is a common and disturbing phenomenon, with a reported prevalence ranging from 7 to 20% [2], [3], [4] and [5] in the general population, and an estimated 10 year incidence rate in adults aged over 48 years of 13% [6]. Approximately 5% of the population is severely affected by their tinnitus [7], for example experiencing sleep disorders, concentration difficulties, and symptoms of anxiety and depression.
Tinnitus can affect a person's satisfaction with quality of life [8], and their physical, emotional, and social functioning [9], as well as leading to a higher incidence of anxiety and depression [10]. However, not everyone with tinnitus will experience the same amount of distress and impairment of quality of life. It is likely that psychological factors – including personality characteristics – mediate the impact of tinnitus. Personality type can influence the vulnerability to, and the severity of, the problem by influencing the tendency to be aware of it [11].
Personality characteristics previously reported to be associated with tinnitus include hysteria and hypochondriasis [9] and [12], introversion [13], withdrawal [9], and emotional isolation [14]. Additionally, particular cognitive strategies, for example, dysfunctional and catastrophic thoughts can increase patients' emotional distress and perceived tinnitus severity, and are thought to be closely related to personality factors [15]. Neuroticism is expressed as “individual differences in the tendency to experience negative, distressing emotions” [16] (p. 301). At one extreme, individuals are characterized by high levels of vulnerability to experience negative emotions, including sadness, fear, anxiety, anger, frustration, and insecurity [17]. At the other end of the spectrum, individuals who score low in neuroticism are more emotionally stable and less reactive to stress. Neuroticism has been associated with adverse outcomes in various health conditions, including increased likelihood of morbidity in those with testicular cancer [18], and an increased likelihood of arthritis, kidney/liver disease, and diabetes in the general population [19]. There is evidence that neurotic traits are stronger in tinnitus patients [20], particularly in those with higher levels of tinnitus annoyance, and recent evidence that neuroticism may predict the development of severe tinnitus in patients already experiencing some tinnitus [21]. In a cross-sectional sample of 530 participants (50% with chronic tinnitus), Bartels and colleagues [22] studied the role of type D personality (the tendency towards negative affectivity and social inhibition) on health-related quality of life and self-reported tinnitus-related distress. Tinnitus patients with type D personality reported greater tinnitus-related distress and poorer health-related quality of life compared to those with other personality types. The authors concluded that some personality characteristics are associated with having tinnitus and are likely to contribute to its perceived severity.
UK prevalence estimates for tinnitus are relatively dated; data for the widely cited National Study of Hearing (NSH) [2] were collected in the 1980's. It is possible that prevalence figures may have changed since then, for example, due to more recreational noise exposure. In addition, neither the NSH nor any other large-scale, population-based study has provided comparisons between tinnitus and neuroticism. The objectives of this study were to provide a detailed description of the prevalence of tinnitus in a large population study of UK adults aged 40 to 69 years, according to age and sex, (following on from a previous study [5]), as well as to examine the link between tinnitus severity and neuroticism.
