October 9, 2013. Losing touch with reality occurs in several mental disorders, including schizophrenia, mood disorders (bipolar disorder or depression) with psychosis, and an in-between diagnosis called schizoaffective disorder. Although psychiatrists define these three psychotic illnesses as separate disorders, recent genetic and brain imaging studies have suggested that they are very similar to each other, differing in the severity of symptoms rather than the kind of symptoms. Finding the natural boundaries among mental illnesses could expedite the search for their causes.
A study published online October 2 in JAMA Psychiatry suggests that these three disorders actually fall into two groups, with schizoaffective disorder grouped with schizophrenia. Led by Roman Kotov at Stony Brook University, New York, the study took into account how the symptoms of these illnesses changed over time and how people functioned in their day-to-day activities 10 years after their initial diagnosis. This long-term view revealed an abrupt difference in psychosis features and 10-year outcome, with mood disorder with psychosis in one category, and schizophrenia and schizoaffective disorder in another. This finding lends support to an old idea that schizophrenia is primarily a thought disorder, whereas mood disorders are rooted in emotional disturbances. (For more details, see the related news story.)—Michele Solis.