Table 1 shows one and two factor solutions for four EFAs. A three-factor solution was not estimated as the eigenvalue for the second factor in a two-factor solution was less than one. Comparing the one- and two-factor solutions, a one-factor solution is the most parsimonious model for existing DSM-IV criteria, based on excellent fit statistics (CFI=0.995, TLI=0.993, and RMSEA=0.023) and only marginal increases in fit moving from a one-factor to a two-factor solution. The eigenvalue for the second factor in the two-factor model was less than 1.0, indicating the second factor does not explain sufficient additional variance in the criteria to be considered a useful addition to the model. The addition of a craving criterion does not materially change the factor structure of the diagnosis. Craving loads on the single factor in the one factor model (0.870), and one factor remains the most parsimonious representation of the data structure with excellent model fit (CFI=0.994, TLI= 0.993, RMSEA=0.022).
