A longitudinal twin study of borderline and XXXX traits in early to middle adulthood.

@entity4225 @entity10420
BACKGROUND: @entity10420 ( @entity10420 ) and @entity4225 ( @entity4225 ) share genetic and environmental risk factors. Little is known about the temporal stability of these etiological factors in adulthood. METHOD: DSM-IV criteria for @entity10420 and @entity4225 were assessed using structured interviews in 2282 Norwegian twins in early adulthood and again approximately 10 years later. Longitudinal biometric models were used to analyze the number of endorsed criteria. RESULTS: The mean criterion count for @entity10420 and @entity4225 decreased 40% and 28%, respectively, from early to middle adulthood. Rank-order stability was 0.58 for @entity10420 and 0.45 for @entity4225 . The best-fitting longitudinal twin model included only genetic and individual-specific environmental factors. Genetic effects, both those shared by @entity10420 and @entity4225 , and those specific to each disorder remained completely stable. The unique environmental effects, however, changed substantially, with a correlation across time of 0.19 for the shared effects, and 0.39 and 0.15, respectively, for those specific to @entity10420 and @entity4225 . Genetic effects accounted for 71% and 72% of the stability over time for @entity10420 and @entity4225 , respectively. The genetic and environmental correlations between @entity10420 and @entity4225 were 0.73, and 0.43, respectively, at both time points. CONCLUSION: @entity10420 and @entity4225 traits were moderately stable from early to middle adulthood, mostly due to genetic risk factors which did not change over the 10-year assessment period. Environmental risk factors were mostly transient, and appear to be the main source of phenotypic change. Genetic liability factors were, to a large extent, shared by @entity10420 and @entity4225 .
