Excessive and repetitive negative thinking (RTN) about past experiences or worries about the future is present across a large range of psychological disorders and appears to be involved in the maintenance of emotional problems. Studies have supported that RNT is characterized by the same process across disorders and can be reliably distinguished from other forms of recurrent cognitions and functional forms of repeated thinking, leading Harvey and colleagues (2004) to propose it as a definite transdiagnostic process.

As a transdiagnostic phenomenon, RNT is underexplored in fibromyalgia (FM), a highly prevalent syndrome characterized by chronic, medically unexplained widespread musculoskeletal pain that causes significant disability. FM is associated with a high prevalence of psychiatric co-morbidity, mostly anxiety and depression, and a large variety of psychological processes. In these patients, cognitive processes and cognitions may play an important role as mediating mechanisms between FM and psychological distress. The content of RNT in patients with FM may be related with excessive monitorization of pain and other physical signs, leading to higher pain intensity and more pain-related fear-avoidance behaviour. In this way, persistence on RNT works as a maladapative coping strategy, impairing emotional regulation and perpetuating psychological distress. Improvement in the understanding of the cognitive processes implicated in FM that could be targeted in cognitive interventions may have positive results in reducing the burden of the syndrome.