Can a Valid Diagnosis of Disruptive Behavior Disorder Be Made in Preschool Children?

Oppositional defiant disorder is characterized by a persistent pattern of negativistic, irritable, and noncompliant behavior (per the DSM-IV criteria). Symptoms include being argumentative and defiant, being easily annoyed by others, and frequently losing one’s temper. Symptoms such as these can be easily identified as problematic at school age, since loss of temper is infrequent and cooperation with rules and routines is expected and necessary for activities of daily life. Thus, the presence of disruptive behaviors per se is reason for clinical concern. During the preschool period, however, the distinction between normative and problematic behavior is much less clear-cut, in large part because developmental changes during this period are associated with behavioral upheaval. The emergence of increasingly sophisticated verbal skills, self-awareness, motor dexterity, and goal-directed behavior contribute to a strong push for independence on the part of the child. At the same time, parents begin to impose rules and limits, both in response to the child’s newfound autonomy and as a natural part of the socialization process. These simultaneous processes contribute to frequent clashes between the child’s self-assertions and the parents’ limit setting, leading to frequent episodes of frustration and upset.

At any developmental period, however, determination of abnormality rests on establishing that the behavior is causing “clinically significant distress or impairment in social, occupational, or other important areas of functioning” (DSM-IV, p. 7). Within this framework, oppositional or defiant behavior during the preschool period is considered clinically significant if it interferes with normal developmental functioning. Since milder forms of oppositionality are frequent during this period, qualitative and quantitative aspects of the behavior, such as its pervasiveness, intensity, and intransigence, are critical to making the distinction between oppositional defiant disorder and typical assertions of autonomy and expressions of frustration.

The essential feature of conduct disorder is a persistent pattern of violation of rules and the rights of others, including aggressiveness and destructiveness. Two fundamental concerns about the validity of a conduct disorder diagnosis in the preschool period have been identified. First, as with oppositional defiant disorder, several behaviors that characterize conduct disorder are common during this period. In particular, aggression is a relatively common response to frustration (8). Here, the same principles of determining clinical significance for symptoms of oppositional defiant disorder would apply to conduct disorder. A second concern is that the diagnosis of conduct disorder rests on the assumption that a child knowingly violates rules, a supposition that requires both knowledge of the rules and intent to break them. Most preschool children are able to understand the concept of rules and can control their behavior accordingly. Preschool children have an emerging conscience and internalizations that enable them to inhibit behavior and follow rules (10). The cognitive ability to generate hypothetical alternatives also emerges during this period (11). Lewis and colleagues (12) demonstrated that children as young as age 3 can deliberately engage in deception when asked about rule violation. Thus, although young children may not be fully aware of the long-term implications of their behavior, there is evidence that they have a basic understanding of the impact of their behavior on others and can control their behavior on the basis of internalized social norms.

Content validity is the extent to which a test or measure covers a representative sample of the behavior domain to be measured (23). For oppositional defiant disorder and conduct disorder in preschool children, content validity has been demonstrated by examining the association of DSM oppositional defiant and conduct disorders diagnoses with other developmentally validated measures of behavior problems, such as Child Behavior Checklist scores, observations of child behavior during standard parent-child interaction tasks, and measures of impairment. Five of the six studies have examined some form of content validity.

In a nonreferred sample of 5-year-olds living in low-income environments, Keenan and colleagues (14) found that children who met the criteria for either DSM-III-R ADHD, oppositional defiant disorder, or conduct disorder were more likely to have externalizing scores in the clinical range on the Child Behavior Checklist. Children with these disorders were also significantly more impaired than children without disruptive or attention deficit disorders.

Ross et al. (15) examined scores on the Eyberg Child Behavior Inventory and Child Behavior Checklist among several different diagnostic groups of preschool children, including those with ADHD only, oppositional defiant disorder only, oppositional defiant disorder plus ADHD, and oppositional defiant disorder plus conduct disorder plus ADHD. Scores on both measures fell within the clinical range for all groups. Children with a diagnosis of oppositional defiant disorder and oppositional defiant disorder plus conduct disorder had higher Child Behavior Checklist scores than children with ADHD only.

Speltz and colleagues (16, 24) reported on a sample of 25 clinic-referred 3–6-year-old preschool boys who met the DSM-III-R criteria for oppositional defiant disorder and scored at the 98th percentile on the aggression scale of the Child Behavior Checklist. Conduct disorder was not assessed. These clinic-referred boys were compared to 25 nonreferred comparison subjects. The differences between the two groups included a higher level of observed noncompliance in the clinic-referred boys (16).

Webster-Stratton and Lindsay (19) examined the relation of disruptive behavior problems to social competence in a sample of 120 4–7-year-olds, half of whom were clinic-referred. Disruptive behavior problems were assessed by using a structured interview with the parent and laboratory observation and were defined as aggression, impulsivity, and oppositionality. Diagnostic specificity was not examined in this study, and rates of specific DSM disorders were not reported. Children with significant disruptive behavior were significantly impaired in social problem solving and prosocial skills with parents and peers.

Lavigne and colleagues (20) assessed the prevalence of psychiatric disorders in preschool children in a pediatric primary care sample weighted to generate population estimates. In this study, DSM-III-R diagnoses were assigned to preschool children on the basis of several sources of information, including an adaptive behavior inventory, the Child Behavior Checklist, and play observation. Thus, all measures that typically would have been used to test concurrent validity were incorporated into the dependent measure of DSM-III-R oppositional defiant disorder, resulting in an inability to test concurrent validity independently.

To our knowledge, only one study has used a diagnostic framework to provide preliminary data on the concurrent validity of both oppositional defiant disorder and conduct disorder in preschool children. Keenan and Wakschlag (1) tested the concurrent validity of DSM-IV oppositional defiant disorder and conduct disorder in a sample of 79 clinic-referred preschool children (2 ½ – 5 ½ years of age) living in low-income environments. These children were referred specifically for aggression, noncompliance, and severe temper tantrums. Parents were administered an established, semistructured diagnostic interview that was modified for developmentally appropriate usage. The children with a diagnosis of conduct disorder had significantly lower Children’s Global Assessment Scale ratings than the children who did not meet criteria for a disruptive behavior disorder. Both oppositional defiant disorder and conduct disorder were associated with elevated scores on the Child Behavior Checklist externalizing factor. Compared to a group of nonreferred children from similar demographic backgrounds, the children with a diagnosis of conduct disorder were more noncompliant, destructive, and aggressive in interactions with their mothers, but the children with a diagnosis of oppositional defiant disorder did not differ from the comparison subjects (22).

Thus, there is adequate support for the content validity of disruptive behaviors problems broadly defined. Few studies, however, have systematically assessed DSM oppositional defiant disorder and conduct disorder separately.

Convergent validity is the extent to which a test or measure correlates highly with other variables with which it should theoretically correlate (23). Convergent validity has been demonstrated by establishing that the correlates of disruptive behavior disorders in preschoolers are consistent with those established for disruptive behavior disorders in older youth. Only a few studies have examined convergent validity, and these have generally focused on parenting and family correlates. Ross and colleagues (15) found that the level of parental stress was higher for children diagnosed with both oppositional defiant and conduct disorders than for children diagnosed with ADHD plus oppositional defiant disorder plus conduct disorder. Speltz et al. (16) reported that both lack of positive involvement and harsh parenting were associated with preschool oppositional defiant disorder.

Lavigne and colleagues (20, 21) compared correlates of DSM externalizing disorders in two groups of preschool children matched on age, gender, and ethnicity. Father absence, family size, family conflict, and maternal psychopathology did not differ between preschoolers who were and were not classified as having ADHD, oppositional defiant disorder, or conduct disorder. The level of negative life events was actually lower in the children with disruptive behavior disorder and/or ADHD than in the group without disorder.

In a study comparing 79 clinic-referred preschoolers to 50 nonreferred comparison subjects who were matched on ethnicity, sex, and family income, Wakschlag and Keenan (22) assessed five primary risk domains: sociodemographic characteristics, parental psychopathology, child characteristics, family environment, and parenting. The children who met the criteria for oppositional defiant disorder or conduct disorder were more likely to have been exposed to cigarette smoke prenatally and were reported to have been more difficult to soothe as infants. There were no significant differences between children who did and did not meet criteria for oppositional defiant disorder or conduct disorder on any of the sociodemographic factors or family environment factors. A history of maternal incarceration was the only parental psychopathology variable that distinguished the children with oppositional defiant disorder or conduct disorder from the comparison subjects. Significant differences were found on several parenting factors, including rates of maternal stress, maternal report of mother-child verbal and physical aggression, and observed lack of maternal responsiveness. Two family risk factors distinguished preschool children with conduct disorder from children with oppositional defiant disorder: younger maternal age at the birth of the first child and absence of the father.

Thus, the risk profile for disruptive behavior disorders in preschool children appears to be similar to that for older children. Infant characteristics and parenting factors were identified as the strongest correlates of oppositional defiant disorder and conduct disorder, relative to the other primary domains of risk measured in the study, especially in samples of children living in predominately low-income environments.

Predictive validity, the extent to which a measured construct demonstrates a predictive relation to the same or a similarly measured construct (23), has been tested in two longitudinal studies. Speltz et al. (17) examined the 2-year diagnostic stability of oppositional defiant disorder in a sample of 92 preschool boys. The vast majority of the children (76%) continued to have oppositional defiant disorder, oppositional defiant disorder plus ADHD, or ADHD alone. Conduct disorder was rare in this group (3%). The authors raised the possibility that oppositional defiant disorder in preschool children may not be a stepping-stone to conduct disorder, as has been documented for older children (25). The question of the longitudinal course of oppositional defiant disorder, which has clear implications for the etiology of conduct disorder, needs to be tested empirically in a more diverse sample.

Lavigne et al. (26) reported that the stability of disruptive behavior disorders (defined as oppositional defiant disorder, conduct disorder, ADHD, or a combination of those disorders) from baseline to follow-up (an average of 2 years later) was moderate. Fifty percent of 2–3-year-old children and 65% of 4–5-year-old children with a baseline diagnosis of disruptive behavior disorder had a disruptive behavior disorder diagnosis at follow-up. However, no data were reported for separate diagnostic categories. The majority of children with a disruptive behavior disorder diagnosis had oppositional defiant disorder (82%).

The results of these two studies provide preliminary evidence that DSM-based disruptive behavior disorders can persist into school age. In addition, a substantial body of literature supports the persistence of a broad range of problem behavior, including temperamental difficultness and aggression, from as early as toddlerhood to school age (27). What remains to be tested is whether there is specificity of prediction to school age for both DSM oppositional defiant disorder and conduct disorder in preschool children in clinic-referred and nonreferred study groups that include both sexes and that are ethnically and sociodemographically diverse.

The majority of the studies reviewed here used structured or semistructured DSM-based interviews that were designed for school-age children and adolescents. Demonstrating that standardized psychiatric interviewing methods can be reliably used for preschool populations has been an important preliminary step. However, nonstandardized modifications of assessment instruments appear to have been used to address the lack of face validity and to establish the clinical significance for many symptoms, particularly for conduct disorder symptoms, such as “use of a weapon.” The studies typically present few or no data on how they assessed oppositional defiant disorder or conduct disorder symptoms in preschool children.

Thus, the development and validation of standardized modifications is a critical next step for the validation of behavior disorders in preschool children specifically and early childhood psychopathology in general. Developmental modifications must be designed to enable the systematic gathering of data that can be used to establish thresholds of clinical significance during the preschool period and to identify the functional equivalence of preschool manifestations of particular symptoms. Since the clinical significance of the symptoms of oppositional defiant disorder and conduct disorder during this period does not merely rest on the presence or absence of a specific behavior, both qualitative and quantitative aspects of the behavior must be assessed to establish symptom thresholds. Additional research is needed to systematically assess dimensions, such as frequency, severity, and pervasiveness to develop empirically based thresholds.

There is no lack of developmentally appropriate rating scales for testing content validity, including the Child Behavior Checklist, Eyberg Child Behavior Inventory, Children’s Global Assessment Scale, and other reliable and valid measures of preschool children’s functioning at school and with peers. However, observational methods for establishing content validity have not been fully explored. Observations of the child both within and outside of the parent-child context may be particularly useful for differentiating problems in parenting from disordered child behavior (28). Thus, standardized observations of child behavior must be included in future validation studies.

Several investigators have incorporated observations of parent-child tasks into their assessments of oppositional defiant disorder and conduct disorder in preschool children (1, 16). In general, the tasks were originally designed to document normative changes in development. As such, these methods have yielded broadly relevant information (e.g., ratings of noncompliance), but they do not appear to be adequately discriminative. Thus, there is a need for standardized observational methods designed specifically to quantify fine-grained manifestations of disruptive behavior in preschool children (e.g., ignoring, defiance, provocation), as well as qualitative dimensions of behavioral dysregulation (e.g., intensity, rate of escalation, lability). Such methods are likely to enhance the diagnostic utility of methods that use parental reports, both in terms of discriminative validity and assessment of the degree of impairment.

Assessing symptoms in the context of the child’s developmental level, while important at any age, is particularly key in making valid diagnoses in the preschool years because many relevant skills emerge during this period and the pace of their emergence varies widely among children (29). We propose that a standardized developmental assessment is necessary in any study of the validity of disruptive behavior disorders in preschool children. The child’s comprehension of social rules is fundamental to establishing the clinical significance of many symptoms of disruptive behavior disorders, particularly conduct disorder, in which many behaviors (e.g., stealing, lying) are considered symptoms only if they involve “deliberate rule violation.” Clearly, for the child to meet criteria for such symptoms, it must be established that the child understands the concept of rules in general and intentionally broke the rules. Consideration of the child’s levels of language ability and social awareness is fundamental to establishing intentionality. Similarly, children cannot lie or be argumentative if they have not yet developed phrase speech. Routine assessment of language ability in validation studies will provide empirical data for establishing specific developmental thresholds.