Does the Duration of the Illness Affect the Severity of Negative Symptoms of Schizophrenia?

Background: The negative symptoms of schizophrenia are less known aspects of the illness although they often mark its course and outcome. Negative symptoms refer to loss of function, and they are associated with poor outcomes. It is considered that they are more prominent with the longer duration of illness.

Objective: To determine the negative symptoms in the patients with schizophrenia with regard to the duration of illness.

Methods: A cross-sectional study was conducted in 60 consecutive outpatients with schizophrenia. Two groups were formed regarding the duration of illness (⩽2 years, and >3 years). The negative symptoms were established with the Brief Negative Symptom Assessment - BNSA.

Results: Average score of negative symptoms in the group with the shorter duration of illness was 8.37±2.94, and in the group with longer duration was 10.73±2.86. Independent Samples Test was significant p=0.003, t-2.367, and therefore the difference between scores on BNSA within groups was significant. Moderate size effect was found (p = 0.69).

Conclusion: Negative symptoms of schizophrenia are more prominent with the longer duration of illness.