[Construct validity and reliability of the Newcastle Endogeniety Index I].

The authors study the construct validity of the Newcastle's Endogeneity Index (NEI). They use the correlation matrix published originally by Carney et al (1965). The results show a high reliability of the NEI (alpha = 0.77). The Factorial Analysis shows two factors, not independent, that explain a 45% of the total obtained variance; it seem to indicate a drop construct validity of the NEI. The authors discuss the validity of the endogenous/neurotic classification of the depression because of the high agreement the NEI and the clinical criterion.