The results of this study support previous research asserting that for children diagnosed with ADHD, symptoms of inattention, hyperactivity and impulsivity decrease with chronological age (Biederman et al., 2000
; Fischer, Barkley, Fletcher, & Smallish, 1993
; Hart, Lahey, Loeber, Applegate & Frick, 1995
). Moreover, this study demonstrates that the transition to middle school is associated with an interruption of this decline in ADHD symptomatology. Regardless of the set of predictors included in our statistical models, a variable indicating the transition to middle school was statistically significant and suggested a disruption in the negative decline in ADHD symptomatology for all domain and rater combinations except for teacher ratings of impulsivity. This finding was unique to children with ADHD as a nonclinical comparison group did not display these trends.
Our analyses provide empirical evidence to support the assertion that the environmental changes associated with transitioning to middle school influences the manifestation of ADHD symptoms among children with ADHD. Interestingly, while the present study supports the hypothesis that the transition is a difficult event for children with ADHD, we found that children without ADHD did not experience significant difficulty with the transition. Thus, the transition appears to disrupt the decline in symptoms of inattention, hyperactivity and impulsivity only for children who exhibited significant levels of ADHD symptoms before the transition.
Both the developmental decline in symptoms of ADHD and the interruption in that decline associated with the transition to middle school were evident even after accounting for MTA treatment and stimulant medication usage. As expected, the use of stimulant medications was associated with decreased ADHD symptomatology across all domains. Based on our findings reported in the 36-month follow-up papers for the MTA (Jensen et al., 2007
; Swanson et al., 2007
), this association is most likely reflecting the strong effect of medication treatment during the active 14-month treatment phase of the study. We did not find that medication use, either study-managed or subsequently self-selected, prevented the interruption in ADHD symptom decline witnessed during the transition year. While medication improves ADHD symptomatology (MTA Cooperative Group, 1999
), medications are unlikely to improve study skills, organizational skills, and time management abilities that are critical to success in middle school. Without these skills, it appears that the developmental decline in ADHD symptoms is disrupted irrespective of whether the child is being treated pharmacologically.
It is noteworthy that the disruption in ADHD symptom decline associated with the transition year and the long-term impact of this disruption (i.e., post transition slope) were more marked as measured by parent ratings (see – ). According to parent ratings, symptoms of ADHD declined at a statistically slower rate following the transition as compared to the pre-transition decline. This trend was not found for teacher ratings of ADHD symptomatology. It is possible that the impact of the transition to middle school is more evident in the home environment. Specifically, the larger disruption in parent rated symptoms may be a function of increased conflict with parents as children move into middle school, including arguments about homework and autonomy. It is also possible that lower reliability of the teacher ratings may have contributed to these differences. That is, all participants were rated by a different teacher at each time point, whereas the same parent completed ratings at each time point. Having different teachers rate the child each year likely increased the within-child variability of the teacher ratings relative to parent ratings because non-specific factors such as response bias, personal perceptions, class composition, etc. varied each year for teacher ratings but likely remained much more stable for parent ratings. Moreover, individual teachers are likely to have much less knowledge of specific children after the transition, given the increased number of classes accompanying the middle school years. In addition, the stability of parent ratings likely benefit from the fact that they have knowledge about past functioning whereas teachers do not. Indeed, variances for teacher ratings at each assessment point were higher for teachers than for parents.
The scope of this paper was limited to the impact of the transition on symptoms of ADHD because other measures of functioning were not examined. Although it is well documented that a wide variety of functional impairments are associated with ADHD in adolescence (Barkley et al., 1990
), it is not clear what triggers these impairments. Determining if the transition to middle school leads to increased functional impairment is important, given the severe nature of impairment difficulties in adolescence (i.e., teen pregnancy, substance abuse, car accidents, and school dropout). Research that includes functional outcomes is particularly relevant because decreased academic confidence and Grade Point Average (GPA) have previously been documented with the transition to middle school in children without ADHD (Alspaugh & Harting, 1995
; Gutman & Midgley, 2000
; Midgley & Urdan, 1992
). Moreover, we recently reported higher rates of delinquency and substance experimentation among the MTA children compared to the LNCG at the 36-month follow-up (Molina et al., 2007
). Thus, there are signs of the expected emergence of these more serious behaviors that should, theoretically, be affected by unsuccessful transitions to secondary education.
Another limitation is that ratings were completed throughout the school year. Specifically, approximately half of the sample was assessed during the first academic semester of school, while the other half was rated during the second academic semester. These assessment timepoints varied within patients across assessments. Differences in rating scale collection have the potential to influence the results as behavior has been shown to vary from month to month over the course of a school year, irrespective of treatment (Evans, Langberg et al., 2005
). Limited research has been conducted on the month to month natural changes in ADHD symptomatology during the course of a year. One report on a small sample showed that teacher ratings of hyperactivity/impulsivity displayed a significant seasonal effect on a placebo condition such that fall ratings of hyperactivity/impulsivity started higher and showed more decline compared to spring ratings (Yao et al., 2005
Implications for Research, Policy, and Practice
These findings may have implications for longitudinal research. The seminal longitudinal studies of children with ADHD completed follow-up assessments years after the initial baseline assessment (e.g., 8 years; Barkley et al., 1990
). With these large gaps between assessments it is likely that clinically relevant changes in symptoms and/or functioning are missed. This point is highlighted by the fact that even using the MTA sample where assessments were completed yearly for the first three years, a disruption such as the transition to middle school was not readily apparent. For example, if we examined the MTA data at baseline, 36-months and 6-years post-baseline, we would likely conclude that symptoms of ADHD decline in a linear fashion with increased age. It is possible that other significant events (e.g., transitioning to college, parents divorcing, and changing schools) are also associated with disruptions in ADHD symptomatology. Future research evaluating how the course of ADHD symptomatology is influenced by significant developmental events may serve to guide targeted intervention research.
These findings also highlight the need for interventions implemented prior to and during the transition to middle school. Investigators have suggested that changes in class size, number of teachers, increased demands for independence and greater workloads make the transition to middle school a difficult event for children with ADHD (Evans, Serpell & White, 2005
; Thompson, Morgan & Urquhart, 2003
; Robin, 1998
). There are numerous academic changes in middle school, including increased expectations related to organization of materials, independent completion of classwork and homework, and the development of study and note taking skills (Evans, Serpell & White, 2005
). An intervention that prepares children with ADHD and their parents for these environmental changes and provides them with the tools necessary to effectively navigate the middle school environment could be particularly beneficial. For example, prior to transitioning, families could receive training in developing and managing an organizational system for academic materials. This could include establishing a specific plan for recording homework and tests in an assignment notebook and for planning out long-term assignments. It is likely that by preparing families, the negative effects of the transition can be minimized, placing children with ADHD on a better developmental trajectory. School-based interventions that specifically target middle school students at-risk for failure and with ADHD have been tested and appear promising (Evans, Langberg et al., 2005
; Langberg et al., 2006
; Molina et al., in press
). However, to our knowledge there is no published research testing the effectiveness of interventions implemented between elementary and middle school.