Psychiatric illnesses are diseases of the mind/brain in which emotions, behavior, cognition and perception are altered. The diagnosis of psychiatric illnesses is mostly based in clinical history and neuropsychological testing, as generally, serological, electrophysiological and imaging examinations are negative. A recent approach named brain connectivity, in which the brain is studied in a sophisticated manner looking for structural and functional relations between brain regions, has been shining a new light on the workings of the brain. In particular, using neuroimaging-based brain connectivity analysis, it has been possible to demonstrate that psychiatric illnesses can be understood as “disconnection diseases”, that is, resulting from the dysfunction of brain’s “electrical circuits”. Nowadays, this approach is rapidly transforming the way we see the brain/mind and improving the diagnosis of psychiatric, as well as, neurological illnesses.   
 
At the Institute of Biophysics and Biomedical Engineering (IBEB) of the Faculty of Sciences of the University of Lisbon, and in collaboration with various national and international institutions, we have been researching the topic of brain connectivity, developing novel tools for the analysis and visualization of brain connectivity, and applying these tools to the study of various psychiatric and neurological illnesses.