Martha B. Denckla, M.D.

Whatever is distinctive about girls with ADHD must be viewed against the background facts concerning how girls in general differ from boys in general; the rate and consequent quality of development differs in well-known ways.  Girls talk earlier and are more easily brought into compliance with social demands like toilet training and sitting still for a meal.  Girls are more natural “people-pleasers” and less natural “environment-explorers” than are boys.  It is likely that adult positive reinforcement of verbal and social skills throws a bias into girls’ choices and then experience/nurture further imbalances girls’ cognitive styles.  In pre-school, only 20% of the little girls will seek out the block corner when free play choices are made available.  The play-time choices are further crowded by girls’ earlier ease acquiring reading and writing skills, heavily positively praised and reinforced.  The mix of nature, nurture, experience, and reinforcement starts so early that studies of gender differences must be interpreted with caution.

There is a biological/natural basis for observed developmental differences.  From mid-gestation, the traditional “quickening” point of pregnancy right on up to puberty (which arrives, on average, earlier in girls than in boys) the brains of girls are more mature in all the stages of cellular migration, proliferation, connectivity, pruning, and myelination.  The left side of the brain, so dominant in language and academic skills, gets such a “headstart” in girls that it may excessively dominate the right side, leading to the observed phenomena of girls excelling up to puberty in the language arts (emphasized in the skill set of elementary school) while boys are the “late bloomers” who emerge in the adolescence as the mathematics/science or even creative leaders. (Sometimes the male high-achievers in high school or college still cannot spell or write legibly!)  A particularly useful piece of my research on normal coordination, the PANESS,1 shows that the timed motor skills curve for kindergarten girls fits perfectly over the one for first grade boys, and this pattern persists through fifth grade!  It is because we have the “folk wisdom” of generations of observations of such developmental differences that we smile and shake our heads as we say, “Boys will be boys” but cannot come up with an analogous saying for a mischievous or messy little girl.

Consider then the plight of the little girl with ADHD, widely acknowledged and publicized mainly in the persons of little boys.  Traditional diagnostic schemes capture four times as many boys as girls under the ADHD heading; but recently it has been suggested that estimated ADHD prevalence figures of 3-5% of the school-age population are under-estimates, due to under-diagnosis of many girls with ADHD.  With the DSM-IV subtype of “predominantly inattentive” ADHD legitimized, some surveys redress the total diagnostic imbalance to the extent of three boys to every one girl with AD(H)D.

Still, it remains the case that girls with AD(H)D (the parenthetical H standing for the “predominantly inattentive” subtype) continue to be under-represented even as candidates for diagnosis because the girls are less disruptive, less likely to be oppositional, less blatantly or obviously off-task than the boys.  Girls, with or without AD(H)D, following their “people-pleaser” tendencies, may appear outwardly attentive to a teacher or go docilely to a bedroom to “do” homework while in actuality day-dreaming, doodling, writing notes to classmates in school, or “instant messaging” on the homework-intended home computer!  Girls with ADHD may appear “passive-aggressive” (and may eventually become so) by saying “yes” to requests to do chores and then forgetting to do them. Even when resembling boys in their ADHD-related physical restlessness or boisterousness, girls with ADHD are rarely as extreme in “physicality”.  Many clinicians, however, are eager to introduce into ADHD diagnostic schemata the physical “hyperactivity and impulsivity” domain of the mouth; girls with ADHD talk more, blurt more, boss more, and even eat more than other girls or their age!  Many clinicians see one subgroup of the current obesity-prone generation as girls with ADHD.  Thus, a genuine physical health risk attaches to girls with ADHD, just as accident-proneness attaches to boys with ADHD.

Girls with ADHD may be more troublesome at home than at school, more impaired socially among peers than academically (at least in elementary school).  They may control themselves in the structured school environment but “let down their hair” and irritate or agitate their families.  Their messiness, sloppy eating habits or even neglect of personal hygiene may be far more alarming to parents than would similar characteristics in a boy.  Psychological interpretations (often only partially relevant) other than possible ADHD may rise to greater prominence than warranted in a messy, sloppy, unkempt girl with ADHD.  Add obesity and a whole chain of social rejection events may complicate the girl’s development.  By middle school, social rejection can loom so large that emotional problems may overshadow the underlying ADHD; adding to the organizational deficits that ADHD (of even the mildest type) usually entail, the unhappy girl does not have the energizing and reinforcing social rewards of school life.  The clinician asked to search for ADHD (any subtype) in a girl of 11 to 14 years is doing a kind of neuropsychiatric “archaeology,” attempting by careful history-taking and neurological/neuropsychological examination to piece together the neurodevelopmental diagnosis underlying an emotional collapse.  Had the girl been referred earlier, the diagnosis of ADHD (not to speak of comorbid learning disabilities experienced by a third of those with ADHD) would have been more evident, less covered over by psychiatric complications and psychotropic drug effects.

What about treatment for girls with ADHD?  As with boys, ADHD requires a customized multimodal treatment program (home/parental management training, school program of accommodations, facilitating achievement, individual psychotherapy or tutoring or both, and adjunctive use of a stimulant medication). Notice the “final position” of medication, which is “neither curse nor cure” and must be customized for each patient at each age level and task demand/supply ratio, titrated very individually towards short-term target improvements and re-addressed frequently!  In this regard, the special needs of girls are simply that each set be described in terms of specific target signs or symptoms, acknowledging that in development all targets are “moving targets.”  The home, school, and individual therapeutic programs for girls with ADHD are even more important than the appropriate adjunctive medications, because the social-emotional complications of ADHD so insidiously overtake the girls before medication may even seem worthy of consideration.

In summary, girls with ADHD present with less-obvious, later-recognized, more “internal” forms of the disorder that Russell Barkley has so succinctly educated us to understand as revealing the nature of all kinds of “self-control.” The price paid by girls with ADHD for their less-obvious, later-recognized course is that emotional complications have more time to gain a foot-hold as comorbid depression or anxiety or “passive-aggressive personality” before correct multi-modal therapeutic programming can be implemented for the ADHD syndrome itself.  There is thus an urgent need to look at little girls with more sensitivity towards manifestations of ADHD, even of the non-disruptive, predominantly inattentive type, lest social rejection and “creeping” academic underachievement combine to make a much more seriously troubled adolescent girl who is, by the way, highly vulnerable to substance abuse.

Martha Bridge Denckla, M.D., Batza Family Endowed Chair; Director, Developmental Cognitive Neurology, Kennedy Krieger Institute;  Professor, Neurology, Pediatrics, Psychiatry, Johns Hopkins University School of Medicine.

Dr. Armando Filomeno —who was at the Johns Hopkins Hospital as a fellow when the KKI’s name was John F. Kennedy Institute for Habilitation of the Mentally and Physically Handicapped Child— thanks Dr. Denckla for this interesting article, which he translated into Spanish for APDA’s electronic newsletter nº 9, issued on September 15, 2005.

(1) Physical and Neurological Examination for Soft Signs (editor’s note).