“…The association between tinnitus and anxiety has been investigated in many previous studies and has been well reviewed (Durai et al, 2016; Malouff et al, 2011; Mazurek et al, 2019; Pattyn et al, 2016; Wallhausser-Franke et al, 2012; Ziai et al, 2017; Zirke et al, 2013). However, no information is available on the direction and causality between the two ends of the link (Danioth et al, 2020; Lugo et al, 2020; Mazurek et al, 2019; Park et al, 2019b; Wallhausser-Franke et al, 2012), although many studies have implied that psychological states, such as those related to common stressors, influence perception of, or coping with tinnitus (Lazarus, 1993; Lazarus, 2000). In this regard, two related systems are involved in tinnitus: (1) the brain regions along the hypothalamic–pituitary– adrenal axis (see reviews (Mazurek et al, 2019; Ziai et al, 2017)), which is the main neuroendocrine system involved in stress response, and (2) the limbic system including the hippocampus and amygdala, which regulates the perception of tinnitus and the adaptation (thereby, the ability to cope with stress) (Chen et al, 2017; Kapolowicz et al, 2019; Leaver et al, 2016; Lockwood et al, 1998; Raghavan et al, 2016; Zhang et al, 2015).…”