Understanding tinnitus distress: introducing the concepts of moderators and mediators.

We focus this theoretical paper on a neglected distinction in tinnitus research between moderators and mediators of tinnitus distress. A moderator variable is one that influences the strength of a relationship between two other variables. In the paper we propose that several variables might act as moderators of tinnitus distress. Degree of hearing loss, arousal, insomnia, characteristics of tinnitus, noise sensitivity, and a range of psychological factors such as personality and perceived control are discussed as potential moderators. We then move on to mediator variables. A mediator variable is one that explains the relationship between the two other variables, and must by definition be caused by a predictor, and then mediate between the predictor and the dependent variable. We propose that stress levels (caused by tinnitus), classical conditioning, selective attention towards tinnitus, and psychological acceptance of tinnitus (versus experiential avoidance) might be mediators of distress. We encourage more research on moderators and mediators of tinnitus distress, as these will help illuminate treatment protocols and how they might work.