Does your ADHD subtype affect intelligence?

Attention Deficit Hyperactivity Disorder (ADHD) is a condition that affects many individuals across the world. It's known for its symptoms of inattention, hyperactivity, and impulsivity. Interestingly, ADHD is not a one-size-fits-all disorder; it has various subtypes, each presenting unique challenges to those who have it. A critical question that arises is: Does your ADHD subtype affect intelligence? This article seeks to explore this question in depth, drawing on recent research and data

Children with the inattentive subtype of ADHD, ADHD-I, tend to show lower cognitive abilities when compared to their peers with other ADHD subtypes.

However, this may result from difficulties with IQ testing, which may reflect a lack of attention rather than an actual deficit in intelligence. For instance, a study by Goodwin et al. in 2011 found that those who took longer to answer questions in IQ tests, often linked with ADHD symptoms, tended to score lower. This suggests that traditional IQ tests might not fully capture the true intellectual capabilities of individuals with ADHD.

Those with the inattentive subtype of ADHD have also been shown to perform worse on tests of memory, while the combined subtype tends to perform worse on tests of executive function, which refers to the higher level thought processes in your brain.

Different ADHD subtypes also show distinct patterns in specific cognitive tests. For example, individuals with ADHD-I have been found to struggle more on tests that require ignoring distractions, like the Stroop test. In contrast, those with the ADHD-C subtype tend to have more difficulties with tests that involve planning and organization, such as the Wisconsin Card Sorting Test (WCST). These differences highlight how ADHD subtypes can influence various aspects of intelligence and cognitive functioning.

Research has also delved into the neurological aspects of ADHD subtypes. A study by Fair DA et al. in 2013 utilized functional MRI to identify distinct neural patterns for different ADHD subtypes. Understanding these neural signatures is crucial as it can lead to more effective treatments and a better grasp of how these subtypes affect cognitive abilities.

A study focusing on Australian youths with ADHD provides further insight into how different subtypes manifest in various age groups. The research indicated that all ADHD subtypes showed more emotional and behavioral problems compared to non-ADHD controls. Specifically, the combined ADHD subtype (ADHD-C) exhibited more problems in behavior and social life. In contrast, the inattentive type (ADHD-I) was linked to lower self-esteem and school issues but showed fewer externalizing problems.

An important factor to consider is that ADHD subtypes are not static; they can change over time. A study analyzing the stability of ADHD subtypes over a five-year period found low stability, indicating that the type of ADHD a person has can evolve. This evolving nature of ADHD subtypes suggests that their impact on intelligence and cognitive abilities may also shift over time, highlighting the complexity of this disorder.