Attention deficit and hyperactivity disorder and nocturnal enuresis co-occurrence in the pediatric population: a systematic review and meta-analysis

Background: Attention deficit and hyperactivity/impulsivity disorder (ADHD) and enuresis are common behavioral disorders in childhood, impacting adolescence and adult life. Enuresis (NE) is an incontinence disorder frequently observed in children with ADHD. The relationship between ADHD and NE has been a matter of debate.

Objectives: We aimed to verify the relationship between ADHD and enuresis and how these conditions can modify each other during development. Using PRISMA guidelines, under the PROSPERO registration number CRD42020208299, we systematically searched the literature and conducted a meta-analysis to answer the following question: how frequent is ADHD and enuresis comorbidity? Twenty-five studies were fully read, and data from seven less heterogeneous case-control studies were pooled to estimate enuresis prevalence comparing ADHD and control samples, whereas six studies were combined to evaluate ADHD frequencies in children with and without enuresis.

Results: We found the ADHD rates in children with enuresis are similar to the enuresis rates in the group of children with ADHD. The presence of ADHD and enuresis comorbidity does not seem to play a role in gender distribution and the presence of other comorbidities in comparison to controls. However, enuresis seems to persist for more time in children with ADHD.

Limitations: The selected papers differed in study type, research question, samples, and controls utilized.

Conclusions: Our systematic review with meta-analysis supports the reciprocal association between enuresis and ADHD. Further studies are necessary to build more robust evidence.