The association between ADHD and physical health: a co-twin control study

Abstract

Attention-deficit/hyperactivity disorder (ADHD) has been associated with increased risk for physical comorbidity. This study used a twin cohort to investigate the association between physical diseases and phenotypic variations of ADHD. A twin cohort enriched for ADHD and other neurodevelopmental conditions were analysed. The Attention Problems subscale of the Child Behavior Checklist/Adult Behavior Checklist (CBCL/ABCL-AP) was used to measure the participants’ severity of ADHD symptoms. Physical health issues were obtained with a validated questionnaire and were tested in relation to ADHD symptom severity in a co-twin control model. Neurological problems were significantly associated with a diagnosis of ADHD. A conditional model for the analysis of within-twin pair effects revealed an inverse association between digestive problems and the severity of ADHD symptoms, after adjusting for co-existing autism spectrum disorder and ADHD medications. Our findings suggest that individuals with ADHD are susceptible to neurological problems, why a thorough neurological check-up is indicated in clinical practice for this population. In addition, health conditions of digestive system could be considered as a non-shared environmental factor for behavioral phenotypes in ADHD. It supports the possible role of gut-brain axis in the underpinnings of ADHD symptoms, at least for a subgroup of individuals with certain genetic predisposition.

Inattention, Impulsivity, and Hyperactivity among Individuals with Self-Reported Impaired Wound Healing

“…Several psychological and medical conditions have ADHD as comorbidity, including mood disorders (e.g., anxiety, depression), substance use disorders, personality disorders, autism, and insomnia [ 17 ]. In addition, neurological and digestive diseases have been associated with ADHD symptomatology as well [ 18 , 19 , 20 ]. As such, it has been suggested that the gut–brain axis may play a common role in in the pathology of both ADHD and these co-occurring diseases [ 21 , 22 , 23 , 24 , 25 , 26 ].…”

Biological Predictors of Treatment Response in Adult Attention Deficit Hyperactivity Disorder (ADHD): A Systematic Review

“…Consequently, pharmacogenetic studies carried out on children affected by ADHD might not be directly applicable to adults. So far, even though genome-wide association studies offer a powerful means to find the genes involved in different neural activities [ 33 , 35 ], only a small number of loci possibly associated with ADHD have been identified until now [ 19 ]. Taken as a whole, more genetic studies are needed, even for genes that were already investigated in relation to ADHD prognosis (e.g., DRD4, SNAP 25, and COMT) [ 63 ].…”

“…However, the treatment response to pharmacotherapy is variable depending on different factors [ 17 ]. Some clinical variables, including age at onset, duration of illness, ADHD presentations, having psychiatric (substance use disorders, major depressive disorder, and personality disorder) and/or neurological (epilepsy and headache episodes) comorbidities, and adherence to treatment, were proposed as possible clinical predictors of treatment response [ 18 , 19 ]. On the other hand, even though no biomarkers were identified as a diagnostic tool for ADHD [ 20 ], some authors tried to detect biological predictors of treatment response in adults affected by ADHD [ 21 ].…”

Epilepsy severity mediates association between mutation type and ADHD symptoms in tuberous sclerosis complex

“…Cortical tubers are likely to impact brain development, for example, frontal systems involved in regulatory activities associated with ADHD, which have been associated with cognitive ability in TSC 7 . There is substantial support for the role of epilepsy in ADHD, regardless of cause, 8 and a history of seizures, intractable epilepsy, and epileptic spasms has been associated with ADHD symptoms in TSC 4,9 . Although the limited research to date suggests that the association between TSC and ADHD is likely to be multifactorial in nature, the majority of studies have relied on retrospective report and chart review.…”