This post is part of a series of guest posts on GPS by the graduate students in my Psychopathology course. As part of their work for the course, each student had to demonstrate mastery of the skill of “Educating the Public about Mental Health.” To that end, each student has to prepare two 1,000ish word posts on a particular class of mental disorders.
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Gender Differences in Specific Learning Disorders by Adam Braly
In my previous post, we explored what it means to conceptualize learning disorders (LD) and addressed the changes in the DSM-5. For this entry, I would like to focus on gender differences in Specific Learning Disorders. The DSM-5 reports the prevalence rate of LD among school-age children of various cultures ranging from 5-15%. It is also reported that the disorder is more common in males than in females with ratios ranging from 2:1 to 3:1 and cannot be attributed to sampling bias, definitional constraints, variations in measurement, language, race or socioeconomic status. This begs the question: what gives, guys?
LD and ADHD are the two most commonly diagnosed learning and behavior problems in schools. Often, the reports of the classroom instructor are often used to assess the behaviors of students, as they are important adults in the lives of each student. Typically, these assessments regard how students will behave or achieve in the future. There is evidence that instructors often miss characteristics that define disabilities, but their assessments are largely unchallenged. Teachers’ involvement in identifying students with LD is more prevalent given the widespread use of response-to-intervention (RTI) models. Their judgments are based on expectation, perception of skills, and formal training in education. It is imperative to make unbiased estimates of student abilities, but is it possible for teachers to miss defining characteristics of LD? Empirically, female teachers more often referred students with learning and behavioral problems; they were predominantly male students. It is not uncommon for LD and ADHD to be comorbid, and males tend to exhibit more disruptive behaviors. Males sitting in class that are not getting the material are going to act out with greater intensity and frequency than females. Girls are more likely to sit quietly and might have the verbal skills to appear as if they understand when they do not. Perhaps the perception is that disruptive is largely due to LD? Expectations for success in school may be greater for males than females which also factors into disruptive behaviors.
Several biological and environmental hypotheses have been proposed to account for gender differences involving X-linked recessive inheritance, differences due to differential exposure or sensitivity to androgens, perinatal complications, and immunological factors.
Although both sexes think that women are bad at mathematics, several analyses [(1),(2),(3),(4)] of gender differences in dyscalculia, across cultures, failed to reveal any significant difference between males and females, in contrast to the notable male bias found in other forms of LD. It turns out for both parties that actually have significant difficulty with math, there didn’t appear to be any difference in way that males and females processed the material. In an interesting study of brain anatomy, researchers suggest that dyslexia may have different neural origins in each sex. MRI scans revealed that among males, and consistent with previous studies, those with dyslexia has less gray matter volume in brain areas such as the left temporal gyrus, which is involved in language. Among females, those with dyslexia had less grey matter volume in the right parietal lobe which is associated with sensory and motor processing. Surprisingly, they found no differences in the temporal lobes of females with dyslexia.
In line with the MRI study above, one study examined the functional frontal lobe in boys and girls (aged 8-12) with ADHD (often comorbid with LD) and saw that both genders displayed reduced supplementary motor cortices. The males, however, showed a reduction in the gray matter of the dorsolateral prefrontal cortex, while females showed reductions in premotor cortices. It would seem that there is a sex-specific variance in brain anatomy that we are not attending to, and perhaps should take into consideration when we study specific disorders. ADHD and dyslexia are conceptualized as a male disorder, but what about disorders that are considered to be female? We consider eating disorders to be typically female-oriented, but could the under-diagnosis of eating disorders in males (yes, males can have eating disorders too) be related to our current lack of understanding regarding females and ADHD or dyslexia? And for that matter, what about being homosexual? There is evidence to suggest that homosexuality should be viewed from a purely biological framework. What happens when we extend this idea to examples that are more common in women than men, like fibromyalgia, lupus, celiac, irritable bowel syndrome, etc… Should we be applying the same catch-all treatment plans for males and females that suffer from similar diagnoses?
Bringing it home, how often do we miss the signs of learning disability in children because their symptoms don’t manifest in the way that we have come to expect? The notion of differences in brain structure between genders might warrant another look at what we consider to be symptoms. Surely academic outcomes as specifiers are in large part a seemingly unbiased tribute to gender differences in LD. In a peculiar way, we discriminate against certain people when we apply catch-all categories and treatment plans to everyone. Then again, we don’t often question our preconceived gender stereotypes by seeking out males with eating disorders or females with dyslexia.
