Abnormalities in the way people process emotions are thought to be central to schizophrenia. People with schizophrenia have a number of different emotional problems including affective flattening, inappropriate affect, anhedonia (inability to experience pleasure), depression, anxiety and anger. They also have abnormalities in emotion perception, emotion experience, emotion regulation and emotional expression. A review of studies by researchers in the U.S. looked at people who were not suffering from schizophrenia but who were thought to be at high risk of the condition including those who had a family history of the illness but who had not developed psychosis themselves, those who were deemed to have schizophrenic tendencies and those who had sought treatment for their psychoses but who had not developed the full-blown condition. This was done to stop results being affected by the effects of the condition itself or the drugs used to treat it. The study found that the individuals at high risk demonstrated similar abnormalities to those with schizophrenia but a lower level. The most common emotional problems in this group were reduced emotional perception, anhedonia and increased negative affect (see post below).
Phillips, Laura K. and Seidman, Larry J. - Emotion processing in persons at risk for schizophrenia Schizophrenia Bulletin September 2008, 34(5), 888-903