The Brief Negative Symptom Scale (BNSS), previously shown to have excellent psychometric properties in schizophrenia, also has value in those with other serious mental illnesses, according to a study involving 123 individuals.
Participants included those with bipolar disorder (n=46), schizophrenia (n=50), and healthy controls (n=27). Investigators assessed negative, positive, disorganized, mood, and general psychiatric symptoms via neuropsychological testing and a clinical interview.
Among the results:
• Those with schizophrenia and bipolar disorder scored higher than controls on BNSS items.
• Those with schizophrenia and bipolar disorder differed on blunted affect and alogia items, but not anhedonia, avolition, or asociality.
• Those with bipolar disorder and a history of psychosis showed the same negative symptom severity as those without a history of psychosis.
The authors concluded that BNSS had excellent internal consistency across all 3 groups.
Citation: Strauss G, Vertinski M, Vogel S, Ringdahl E, Allen D. Negative symptoms in bipolar disorder and schizophrenia: A psychometric evaluation of the brief negative symptom scale across diagnostic categories. [Published online ahead of print December 29, 2015]. Schizophr Res. doi: http://dx.doi.org/10.1016/j.schres.2015.12.014.