Assessment of Premorbid Social Competence in Schizophrenia: A Methodological Note

The developmental theory underlying the Zigler-Phillips Social Competence Scale (ZPSCS; Zigler & Phillips, 1961) has important implications for using the scale to assess premorbid adjustment in schizophrenia. Many studies using the ZPSCS have scored the scale in an inconsistent manner or have not clearly limited the premorbid period to that prior to the onset of illness. ZPSCS ratings of social competence change over time, therefore studies using the ZPSCS should attend closely to the definition of the premorbid period and indicate whether premorbid or current adult social competence is being assessed.