MedWire News: Patients with schizophrenia who have predominant negative symptoms and those with merely prominent negative symptoms respond similarly to treatment with atypical antipsychotics in terms of improvement in negative symptom scores, research shows.

"Positive symptoms often respond well to antipsychotic agents, whereas negative symptoms, commonly associated with poorer functioning and lower quality of life, have historically been more resistant to treatment," explain Virginia Stauffer (Lilly Corporate Center, Indianapolis, Indiana, USA) and team.

For the current study, the researchers enrolled 343 patients with schizophrenia or schizoaffective disorder to investigate whether those with predominant negative symptoms differed in their negative-symptom response to atypical antipsychotics compared with those with merely prominent negative symptoms.

Prominent negative symptoms (n=224) were defined by a baseline score of at least 4 on at least three, or a score of at least 5 on at least two, of the seven negative subscale items of the Positive and Negative Syndrome Scale (PANSS).

Predominant negative symptoms (n=119) were defined by the criteria used for prominent negative symptoms plus a total positive symptom subscale PANSS score of less than 19, a Barnes Akathisia Scale score of less than 2, a Simpson-Angus Scale score of less than 4, and a Calgary Depressive Scale score of less than 9.

All of the participants received treatment with atypical antipsychotics for up to 24 weeks.

At baseline, patients with prominent negative symptoms had a significantly longer mean duration of illness compared with those with predominant negative symptoms (18.5 vs 15.9 years), as well as reduced functioning and greater overall symptom severity, as reflected by mean total Global Assessment of Functioning Scale (GAF) and PANSS scores of 41.9 versus 44.6, and 90.4 versus 74.2, respectively. However, there were no significant differences between the groups regarding baseline mean PANSS negative subscale scores, at 25.0 versus 23.7.

Changes in negative symptoms over the study period followed largely similar patterns of improvement between the groups, with no significant difference regarding the magnitude of improvement.

There were also no significant differences between patients with predominant and those with prominent negative symptoms regarding improvements in GAF scores over the study period, at 3.7 versus 3.5, respectively.

Stauffer and team conclude in the journal Schizophrenia Research: "The findings of this post hoc analysis indicate that patients with either predominant or prominent negative symptoms respond similarly to treatment with atypical antipsychotics.

"This suggests that negative symptoms, regardless of their association with positive, affective, and extrapyramidal symptoms, may respond to treatment with second-generation antipsychotic medications."

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