Emotion processing deficits: a liability spectrum providing insight into comorbidity of mental disorders.

Epidemiological studies have revealed that mental disorders are highly comorbid; almost half of the people with a mental disorder also meet the criteria of another disorder. The explanation of this high comorbidity has remained a scientific puzzle. We propose 'disrupted emotion processing' as a liability spectrum that underlies many different mental disorders. Emotion processing deficits have been reported in different disorders and result in difficulties in regulating emotions and at the perceptual level in attentional biases and impaired recognition of emotional expressions. This article provides a detailed overview of the literature on disrupted emotion processing in clinical groups on the behavioral and neurological level. In the discussion, the similarities and differences between these disorders are discussed in the context of common neuro-endocrine, genetic and environmental factors and ideas are put forward on how future research may advance. Most importantly, more interdisciplinary research is needed in which different techniques, tasks and clinical populations are combined to get a better understanding of disrupted emotion processing as a liability spectrum underlying various different mental disorders.