Primary negative symptoms of schizophrenia can impact domains of functioning directly1

Key message: Negative symptoms and cognitive deficits can cause patients functional impairment. Primary negative symptoms of schizophrenia can impact different domains of functioning directly, including interpersonal relations, use of common objects and activities, and instrumental role functioning.

Background

• The sample included 1,427 patients (aged 18–65) with schizophrenia who completed the baseline visit in the Clinical Antipsychotic Trial of Intervention Effectiveness (CATIE) schizophrenia study.^{[Fervaha et al, 2014]}
• Symptoms were assessed by the Positive and Negative Syndrome Scale and Calgary Depression Scale, extrapyramidal side effects with the Simpson–Angus scale, and real-world functional status with the Heinrichs–Carpenter Quality of Life Scale (QLS).^{[Fervaha et al, 2014]}
• Primary negative symptoms were assessed using the negative symptom factor score from the Positive and Negative Syndrome Scale (PANSS), which includes the following items: blunted affect, emotional withdrawal, poor rapport, apathetic social withdrawal, lack of flow, motor retardation and active social avoidance.
• The intrapsychic foundations subdomain of the QLS has been cited to have conceptual overlap with certain negative symptoms, therefore it was not included in the analyses.^{[Fervaha et al, 2014]}
• Pearson’s product-moment correlations were computed to examine the zero-order relationship between negative symptoms and each domain of functioning, including interpersonal relations (social), instrumental role functioning (vocational), and use of common objects and activities (recreational). The potential influence of various clinical variables on negative symptom severity was examined using correlation analysis.^{[Fervaha et al, 2014]}
• Negative symptoms were significantly correlated with each domain of functioning, including interpersonal relations (r =-0.42, P < 0.001), instrumental role functioning (r=-0.24, P < 0.001), and use of common objects and activities (r =-0.30, P < 0.001); for all domains assessed, greater negative symptom burden was associated with poorer functioning.^{[Fervaha et al, 2014]}

References:
Fervaha G, et al. Eur Psychiatry. 2014; 29 (7): 449–55.

Lehman AF, et al.^{[APA Practice Guidelines]} 2010.