Identifying and evaluating novel treatment targets for the development of evidence-based interventions for functional neurological disorder.

Historically, functional neurological disorder (FND) has been described in psychodynamic terms as the physical manifestation of psychological distress. It is often explained to patients and caregivers as the result of anxiety, stress, trauma or other psychiatric comorbidities. However, recent evidence indicates that targeting mood and stress is not equivalent to the treatment of FND and may have limited to no effect on FND symptoms. Given the few randomized controlled trials for FND treatments and the limited evidence of mood and stress as effective treatment targets, the identification and evaluation of novel treatment targets or mediators is an area of great opportunity and should be the focus of future research. Identifying and targeting modifiable disease mechanisms directly as opposed to only treating psychiatric comorbidities may result in greater efficacy in treating FND symptoms, better patient outcomes and lower healthcare costs. Several novel mechanisms have been identified that warrant additional investigation as potential treatment targets including abnormal attentional focus on the affected area, beliefs and expectations about illness, impairments in habituation, and decreased sense of control over actions. Future intervention studies should take a mechanism-based approach and utilize valid and reliable measures or specific biomarkers to determine whether improvements in FND symptoms are associated with changes in the treatment targets. This transdiagnostic approach will allow researchers to translate the novel mechanistic outcomes emerging from neurophysiological and neuroscience studies into new or improved evidence-based approaches to FND treatment and prevention.