Rates of ODD and CD at baseline
Among the 223 preschoolers, 89 met DSM-IV criteria for ODD (91.0% of who were from the clinically referred group). Seventy-six preschoolers met DSM-IV criteria for CD, (89.5% of who were from the clinically referred group). There were no significant sex differences in the rate of ODD or CD. Of the 103 children who met criteria for ODD and/or CD, 62 (60.2%) met criteria for both disorders, 27 (26.2%) met criteria for ODD, but not CD, and 14 (13.6%) met criteria for CD but not ODD. Half of the 14 preschoolers who met criteria for CD but did not meet criteria for ODD had 3 symptoms of ODD at baseline, approximately a third (35.7%) had 2 symptoms, and the remaining two cases had one and no symptoms of ODD at baseline, respectively.
Among those diagnosed with ODD, the most commonly endorsed symptoms were defiance (100.0%), losing temper (94.4%), annoying others on purpose (84.3%), and blaming others for her own mistakes (78.7%). Among those children diagnosed with CD at baseline, the most commonly endorsed symptoms were using an object to harm someone (85.5%), physical aggression towards others (84.2%), lying to con (72.4%), destroying property (50.0%), and stealing (44.7%).
Stability of ODD and CD across three years
Using diagnosis at baseline as the denominator, 72.0%, 66.3%, and 51.7% of the children diagnosed with DSM-IV ODD at baseline met criteria at the 12-, 24-, and 36-month follow-up, respectively, and 82.1% met criteria in at least one of the three follow-up assessments. Of the children who met criteria for CD at baseline, 48.6%, 33.3%, and 26.0% met criteria for CD at the 12-, 24-, and 36-month follow-up, respectively, and 61.1% met criteria in at least 1 of the three follow-up assessments.
As shown in , very few children diagnosed at baseline were symptom free during the follow-up. In addition to the 82.1% of children meeting criteria for ODD during follow-up, another 8.3% had years in which 3 of the 4 symptoms required for meeting criteria were present, and only 1 (1.2%) child remained free of ODD symptoms during the 36-month follow-up (). Among those diagnosed with CD and assessed at follow-up (N = 72), in addition to the 61.1% who met criteria for CD, 20.8% had years in which 2 of the 3 symptoms required for CD were present, and only 6 (8.3%) of those diagnosed at baseline were symptom free throughout the 36-month follow-up ().
Outcome of preschoolers meeting criteria for DSM-IV ODD and CD at ages 3–5 years
There were 30 new cases of ODD during the follow-up. Close to half (46.7%) of those children had 3 symptoms of ODD at baseline, 10 (33.3%) had 2 symptoms and 6 (20.0%) had no symptoms of ODD at baseline. However, of the six children with no ODD symptoms at baseline who developed ODD during the follow-up, all but one were reported to have symptoms of CD. Eleven new cases of CD were observed during the follow-up; all but one of the new onset cases had symptoms of CD at baseline.
Predictive validity of preschool diagnosis
The likelihood of meeting criteria for ODD at a subsequent assessment was tested using logistic regression with ODD diagnosis at baseline, race, and sex entered simultaneously. Race had no significant effect, and so was dropped from the models presented here. The odds (95% CI) of meeting criteria for ODD given a diagnosis at baseline were 16.3 (8.1 – 33.1), 16.4 (7.8 – 34.7), and 10.8 (5.2 – 22.3) for the 12, 24, and 36-month follow-ups, respectively. The odds of meeting criteria at least once during the 36-month follow-up were 18.1 (8.5 – 38.5) (). Sex was a significant predictor of ODD at the 24- and 36-month follow-up assessments; 20 of the 30 the new onset cases were boys. The interaction between sex and preschool ODD on subsequent ODD was tested but was not significant.
Predictive validity of preschool ODD across 3 years
The odds of meeting criteria for CD given a diagnosis at baseline were 20.4 (8.0 – 52.5), 22.6 (6.4 – 79.0), and 7.3 (2.7 – 19.7) for the 12, 24, and 36-month follow-ups, respectively. The odds of meeting criteria at least once during the 36-month follow-up were 15.6 (7.1 – 34.0) (). Sex was a significant predictor of CD at the 36-month follow-up assessments, with more boys than girls meeting criteria. Of the 11 new cases of CD, 8 (72.7%) were boys. The interaction between sex and baseline CD on subsequent CD was tested but was not significant.
Predictive validity of preschool CD across 3 years
Reciprocal Influence of ODD and CD on stability
As stated earlier, co-occurrence of ODD and CD was common at baseline. Approximately half (53.8%) of the 223 children did not meet criteria for either disorder, 14 (6.3%) met criteria for CD but not ODD, 27 (12.1%) met criteria for ODD but not CD, and 62 (27.8%) met criteria for both disorders. We tested whether ODD, CD, and the co-occurrence of the two accounted for unique variance in meeting criteria in at least 1 of the three follow-up assessments. In predicting later ODD, a diagnosis of ODD at baseline (OR = 10.1, 95% CI = 3.9 – 30.8, p < .001), and a diagnosis of CD at baseline (OR = 3.6, 95% CI = 1.2 – 11.5, p < .05), but not their co-occurrence (OR = 0.5, 95% CI = 0.1 – 2.6, p > .10) were unique predictors. A later diagnosis of CD during the three-year follow-up period was predicted by a diagnosis of CD at baseline (OR = 5.3, 95% CI = 1.3 – 21.1, p < .05), but not a by diagnosis of ODD at baseline (OR = 3.1, 95% CI = 0.8 – 11.7, p > .10), nor by their co-occurrence (OR = 1.8, 95% CI = 0.3 – 11.5, p > .10).
Impairment as a function of ODD and CD diagnostic stability
Mutually exclusive diagnostic stability groups were created to test differences in average impairment ratings over time using caregiver report on the C-GAS. Children were categorized as having no diagnosis, or a diagnosis that was chronic (i.e. meeting diagnostic criteria in at least 2 of the 3 follow up assessments), in full remission (i.e., no diagnosis at any of the three follow-ups), in partial remission (i.e., meeting criteria in only 1 of the three follow-ups), or as having a new onset (i.e. children meeting criteria after the baseline assessment). The total n for these analyses was 186: the number with complete follow-up data.
As shown in , a significant interaction of time and diagnostic stability of ODD on impairment levels was observed (F [4,181) = 13.31, p < .001, eta = .37). We conducted post-hoc comparisons using a Bonferroni correction to test whether each diagnostic stability group differed from the no diagnosis group and from each other on impairment ratings over time. These post-hoc tests revealed significant differences between the no diagnosis group and each of the four other groups, between the partial and full remission groups and the chronic group, and between the new onset group and the chronic group ().
Average rating of functional impairment over time as a function of ODD diagnostic status
ODD diagnostic groups also were compared on baseline impairment ratings. This analysis yielded a significant difference overall (F [4, 181) = 39.20, p < .001, eta = .68), with post-hoc comparisons revealing significant differences between the no diagnosis and all other groups, but no significant differences among children with chronic, recurring, or remitting ODD.
A significant interaction of time and diagnostic stability was observed for CD as well (F [4, 181) = 6.47, p < .001, eta = .35). Pot-hoc comparisons using a Bonferroni correction revealed the same pattern as that generated for ODD: significant differences between C-GAS ratings over time were found between the no diagnosis group and each of the other four groups, the partial and full remission groups compared to chronic group, and the new onset group compared to the chronic group (). A test of baseline impairment ratings showed a similar pattern to ODD (F [4, 181) = 44.63, p < .001, eta = .70), revealing significant differences between the no diagnosis and all other groups. In addition, the level of impairment at baseline for preschoolers who would go on to follow a chronic course of CD was significantly greater than those whose course would be characterized as partial or full remission during the follow-up period.
Average rating of functional impairment over time as a function of CD diagnostic status
Sex and race effects on the chronicity of and remission from ODD and CD
Finally, we examined whether sex or race was associated with chronicity and remission of disorder. For these analyses we used the above mutually exclusive groups, but excluded the no diagnosis and new onset cases, because we were primarily interested in the effects of race and sex on chronicity, and because we knew already from the predictive validity analyses that boys were over-represented among the new onset cases.
Race had no effect on chronicity of ODD (χ2 (df = 2) = 1.11, p > .10) or CD (χ2 (df = 2) = 0.41, p > .10). There was a significant effect of sex on the chronicity of CD (χ2 (df = 2) = 7.80, p < .05), but not on the chronicity of ODD (χ2 (2) = 1.64, p > .10). Among the 29 girls with CD, 11 (37.9%) demonstrated full remission, 13 (44.8%) demonstrated partial remission, and 5 (17.2%) had chronic CD. Among the 38 boys, 17 (44.7%) demonstrated full remission, 6 (15.8%) demonstrated partial remission, and 15 (39.5%) had chronic CD. Thus, girls were less likely to manifest chronic CD than were boys.