3.3 T HE DEVELOPMENTAL COURSE OF ADHD
3.3.3 Adolescence
By late childhood and preadolescence, these patterns of academic, familial and social conflicts have become well established for many ADHD children. At least 40- 60% have developed Oppositional Defiant Disorder (ODD) and as many as 25-40%
are likely to develop symptoms of Conduct Disorder (CD) and antisocial behaviour between 7 and 10 years of age (Barkley, Fischer et al., 1990; Biederman, Faraone, Taylor, Sienna, Williamson & Fine, 1997). The most common symptoms are lying, petty thievery, and resistance to the authority of others. At least 25% or more may have problems with fighting with other children. It is the minority of ADHD children who have not developed some comorbid psychiatric (ODD/CD), academic (learning disability and underachievement), or social disorder by this time. Those who remain purely ADHD whose attention problems are most prominent are likely to have the best adolescent outcomes, experiencing problems mainly with academic performance and eventual attainment (Fergusson, Lynskey & Horwood, 1997; Weiss
& Hechtman, 1993). For others, an increasing pattern of familial conflict and antisocial behaviour in the community may begin to appear or worsen where it already existed. Such family conflicts often prove particularly recalcitrant to treatment (Barkley, Guevremont, Anastopoulos & Fletcher, 1992).
The majority of ADHD children (60-80%) have by this time been placed on a trial of stimulant medication, and over half have participated in some type of individual and family therapy (Barkley, DuPaul & McMurray, 1990; Barkley, Fischer et al., 1990;
Faraone et al., 1993; Munir, Biederman & Knee, 1987; Semrud-Clikeman et al., 1992). Approximately 30-45% will also be receiving formal special educational assistance for their academic difficulties by the time they enter adolescence. Some gains in scholastic performance have been achieved through cognitive-behavioural programmes that teach ADHD children how to set academic goals that require sustained attention, while allowing these youngsters to reinforce their success with tokens that can be exchanged for prizes (Shaffer, 2002).
adolescence, and substance use is relatively common among teenagers, in spite of their knowledge of the potential risks.
With regard to cognitive development, formal operational reasoning introduces thinking in terms of abstractions, rather than relying upon concrete representations.
Adolescents now have the capacity to integrate abstract concepts and co-ordinate a number of mental processes. Improvements in deductive reasoning allow adolescents to apply logic more effectively. Discovery of their newfound independent reasoning ability contributes to a new egocentric phase, during which they perceive themselves as special, invincible and under extreme public scrutiny.
The increasing independence and breadth of choices confronting adolescents necessitates that they capitalise upon their ability to learn formal decision-making and problem-solving techniques. Information-processing ability improves as adolescents work with increasingly more familiar material, experience opportunities to practice information-processing skills, build larger knowledge bases, and develop new information processing skills. New skill attainment is affected both by direct instruction and developmental maturity. Language ability is enhanced by ongoing improvements in grammar and vocabulary. Adolescents’ experience of reading begins touching upon more abstract, hypothetical notions such as possible motives and symbolism. The ability to perform more complex mathematical manipulations is supported by adolescent improvements in attending and ability to consider multiple variables. Children’s earliest career fantasies involve jobs that sound exciting or have high visibility. At adolescence, they begin assessing their interests and abilities realistically as they consider potential careers.
With regard to social and emotional development, identity formation requires independent adolescent self-exploration, often resulting in considerable oppositional or rebellious behaviour. Adolescents need to sort out multiple and conflicting facets of selfhood as they establish an independent self-concept. Cultural gender expectations affect their identity formation.
During adolescent individuation, relationships with parents become more conflictual, especially with mothers; and less cohesive, particularly with fathers. However, teenagers continue to benefit emotionally and cognitively from secure attachments to parents, even though this attachment may be more aloofly expressed. Peer relationships become more influential during adolescence, providing more emotional
supportiveness that they do for younger children. Academic achievement, identity formation and emotional adjustment are associated with an adolescent’s choices of crowds, cliques and individual friendships. Younger adolescents are more influenced by peers than are older ones, and girls place more importance on social relationships than do boys. Dating during adolescence provides a means of practicing couplehood, both personally and socially. Adolescents are easily susceptible to excessive social influence.
Increases in emotionality during adolescence are in part associated with hormonal changes and adjustment to more complex cognitive processing. Children invest the greatest amount of energy in regulation of emotional expressiveness during the early teen years. Adolescents commonly experience normal depressive moods as they sort out and react to developmental issues. Depression reaches clinical levels twice as often in adolescent girls as in boys, and adolescents attempt suicide more than any other age group. Adolescents’ advances in moral reasoning correspond with their greater understanding and ability to manipulate abstractions
ADHD children
It was once believed that hyperactive children simply outgrew their problems after reaching puberty. As a result, parents sometimes delayed getting help, expecting their children’s difficulties to go away by adolescence (Kendall, 2000). Although there is generally a decline in their levels of hyperactivity and an improvement in their attention span and impulse control (Hart et al., 1995), 70-80% of ADHD children are likely to continue to display these symptoms into adolescence to an extent inappropriate for their age group (Barkley, Anastopoulos, Guevremont & Fletcher, 1991; Barkley, Fischer et al., 1990). As many as 25-45% of the adolescents display oppositional or antisocial behaviour or CD (Biederman et al., 1997), and 30-58%
have failed at least one grade in school (Barkley, Anastopoulos et al., 1991; Barkley, Fischer et al., 1990; Brown & Borden, 1986). Other studies clearly show these children to be significantly behind matched control groups in academic performance at follow-up (Fischer, Barkley, Edelbrock & Smallish, 1990; Lambert, Hartsough, Sassone & Sandoval, 1987; Weiss & Hechtman, 1993).
As Ross and Ross (1976) have indicated, the adolescent years of ADHD individuals may be some of the most difficult because of the increasing demands for independent, responsible conduct, as well as the emerging social and physical changes inherent in puberty. Issues of identity, peer group acceptance, dating, and
physical development and appearance erupt as a source of demands and distress with which the ADHD adolescent must now cope. Sadness, major depression in as many as 25% of cases, poor self-confidence, diminished hopes of future success, and concerns about school completion may develop.
A detailed picture of the adolescent outcome of ADHD children has emerged from a study by Barkley and his colleagues (Barkley, Fischer et al., 1990). The study consisted of a large sample of ADHD and normal children followed prospectively eight years after their initial evaluation. Unlike past studies, the clinic referred children diagnosed as hyperactive fulfilled a set of rigorous research criteria designed to select a sample of children who were truly developmentally deviant in their symptoms relative to same-age normal children.
The initial sample in Barkley’s study consisted of 158 hyperactive children and 81 normal children between four and 12 years of age. A total of 123 hyperactive children and 66 normal children were located and agreed to be interviewed and complete the questionnaires. This represents a total of 78% of the original sample for hyperactive children and 81% for the normal group. In the hyperactive group, 12 of the subjects (9.7%) were female and 111 were male, whereas in the normal group four of the subjects (6.1%) were female and 62 were male.
With regard to comorbidity for other disruptive behaviour disorders, 59% of the hyperactive group met DSM-III-R criteria for a diagnosis of ODD, as compared to 11% of the control group. Approximately 43% of the hyperactive group qualified for a diagnosis of CD using DSM-III-R criteria, as compared to only 1.6% of the control group. The mean age of onset for ODD was 6.7 years and for CD was six years.
Previous research has been equivocal concerning whether the rates of substance use and abuse among hyperactive adolescents differ from that of normal adolescents. Barkley’s study (Barkley, Fischer et al., 1990) found that cigarette and alcohol use are the only categories of substance use that significantly differentiate the hyperactive and normal teenagers, according to teens’ self-reports. A previous follow-up study by Gittelman, Mannuzza, Shenker and Bonagura (1985) found that the differences between clinically diagnosed hyperactive children and the control group in substance use at adolescent outcome were primarily accounted for by those hyperactive teens that received a diagnosis of CD. In agreement, a study by Lynskey and Fergusson (1995) found that rates of adolescent substance use and abuse were
elevated only in ADHD children having comorbid conduct problems as children.
Barkley’s study (Barkley, Fischer et al., 1990) separated subjects into those who were purely hyperactive and, in agreement with the above studies, found no greater use of cigarettes, alcohol or marijuana than did normal subjects. However, the mixed hyperactive/CD subjects displayed two to five times the rate of use of these substances than the pure hyperactive or normal subjects.
With regard to academic outcome, Barkley’s study (Barkley, Fischer et al., 1990) showed that the academic outcome of the hyperactive adolescents was considerably poorer than that of the normal adolescents, with at least three times as many hyperactive subjects having failed a grade (29.3% versus 10%), been suspended (46.3% versus 15.2%), or been expelled (10.6% versus 1.5%). Almost 10% of the hyperactive sample followed into adolescence had quit school at this follow-up point, compared to none of the normal sample. Levels of academic achievement on standard tests were also significantly below normal on tests of mathematics, reading and spelling. Barkley and his colleagues (Barkley, Fischer et al., 1990) again examined whether the presence of CD at follow-up within the hyperactive group accounted for these greater than normal rates of academic failure. The results indicated that, although hyperactivity alone increases the risk of suspension and dropping out of school, the additional diagnosis of CD greatly increases these risks.
Moreover, the presence of CD accounts almost entirely for the increased risk of expulsion within the hyperactive group, in that the pure hyperactive group does not differ from normal in expulsion rate (1.6 versus 1.5%), whereas 21.7% of the mixed hyperactive/CD group had been expelled from school. In contrast, the increased risk of grade retention in the hyperactive group is entirely accounted for by their hyperactivity with no further risk occurring among the mixed hyperactive/CD group.
Barkley and his colleagues also examined the extent of various interventions received in the ensuing eight years since initial evaluation and their durations for both groups. Not surprisingly, more ADHD children had received medication and individual and group therapy as well as special educational services than had normal children.
Similar results were found in a later study by Barkley (Barkley, Anastopoulos et al., 1991) involving clinic-referred adolescents having ADHD. In terms of the duration of treatment among those receiving it, the hyperactive children had received a substantial period of stimulant medication treatment (mean of 36 months) and individual and family therapy (16 and 17 months respectively), as well as special educational assistance for learning, behavioural and speech disorders during the
past eight years (65, 59, and 40 months respectively) (Barkley, Fischer et al., 1990).
This pattern is similar to that found in Barkley’s study of clinic-referred ADHD teens (Barkley, Anastopoulos et al., 1991) and Lambert’s follow-up study of 58 hyperactives and controls (Lambert et al. 1987).
With regard to automobile accidents, a later study by Barkley and colleagues (Barkley, Guevremont, Anastopoulos, DuPaul & Shelton, 1993) confirms prior research (Weiss & Hechtman, 1993) that suggested that hyperactive adolescents have a higher incidence of automobile accidents than do normal adolescents.
Barkley’s study followed ADHD teens prospectively for three to five years and found that they were significantly likely to have had more crashes, to have more bodily injuries associated with such accidents, and to be at fault more often for such accidents. They were also more likely to receive traffic citations, particularly for speeding.