Standardised rating scales in psychiatry: methodological basis, their possibilities and limitations and descriptions of important rating scales.

Standardized rating scales are an important tool to improve the assessment of psychopathological symptoms in terms of validity and reliability. Especially observer-rated scales are of primary importance in this respect. Self-rating scales can give a meaningful complementary view to the findings of observer-rated scales. Besides scales covering more or less the whole spectrum of psychopathological symptoms, specialised scales focussing only on symptoms of disorders like schizophrenia or depression were developed. They are widely used, specifically for pragmatic reasons.