Neuroimaging distinction between neurological and psychiatric disorders†

BACKGROUND It is unclear to what extent the traditional distinction between neurological and psychiatric disorders reflects biological differences. AIMS To examine neuroimaging evidence for the distinction between neurological and psychiatric disorders. METHOD We performed an activation likelihood estimation meta-analysis on voxel-based morphometry studies reporting decreased grey matter in 14 neurological and 10 psychiatric disorders, and compared the regional and network-level alterations for these two classes of disease. In addition, we estimated neuroanatomical heterogeneity within and between the two classes. RESULTS Basal ganglia, insula, sensorimotor and temporal cortex showed greater impairment in neurological disorders; whereas cingulate, medial frontal, superior frontal and occipital cortex showed greater impairment in psychiatric disorders. The two classes of disorders affected distinct functional networks. Similarity within classes was higher than between classes; furthermore, similarity within class was higher for neurological than psychiatric disorders. CONCLUSIONS From a neuroimaging perspective, neurological and psychiatric disorders represent two distinct classes of disorders.