In our study, we traced the association between enuresis and ADHD in children from 6 to 12 years taken from Mansoura University Pediatric and Psychiatric Outpatient Clinic. The number of cases complaining of enuresis was 100, 40 of them were found to have symptoms of ADHD with a prevalence rate of 40%. This high rate of ADHD in our study because most resistant and problematic cases are usually referred to university hospitals, which is a tertiary care unite. This was very similar to the previous conducted studies [2, 8]. They explained that the association between both enuresis and inattentive ADHD subtype may be due to a deficits in arousal. Other studies reported that the rate ranges from 10 to 20%, which may be due to differences in the sampling method or due to different age groups [18, 19].
Our data also revealed that the older the children, the higher the prevalence of the ADHD, this finding reflects the potential importance of ADHD as a comorbidity factor in a therapy resistant population and indicate the importance of screening and early treatment of ADHD. This was similar to a study made by Bayens who found the maximal prevalence of enuresis at age of 8 years, followed by a decline to age 11 years which was consistent with the findings that the older the children, the higher the prevalence of the ADHD [5].
By studying gender disparity between the groups in our study, there was a male predominance with about 2:1 male to female ratio. This data is in concordance with a study of Tai HL, Sheerman [6, 20]. Where ADHD is similar to enuresis, as in each disorder, boys are generally more often than girls. Thus, the chance for boys having enuresis to have increased behavioral problems is twice as high as for girls with enuresis. This was similar to an epidemiological study in Moroccan children [21].
Socio-economic level revealed that most of children of the 3 groups had mainly very low or low scores, as they were coming mostly from rural areas. This was similar to a study of Beiderman J who reported that enuresis is strongly associated with social disadvantage, as psychopathology such as ADHD [22]. It has been postulated that socioeconomic status (SES) is a common underlying factor by which behavioral problems and enuresis emerge simultaneously [23].
Other risk factors of enuresis include family history of enuresis which is similar to studies of Bayoumi RA and Wang QW [24, 25]. Considering the family history of enuresis in a study by Ismail et al., more than fifty of children of enuresis had a positive family history, which was explained by presence of genetic factor in occurrence of enuresis; however, this result was slightly higher than our study, as family history involved only the first-degree relatives [18].
EEG (electro-encephalography) was done to confirm the underlying pathology in each group. Enuresis with ADHD group had an association between EEG abnormalities with a family history of enuresis, in which generalized slow and sharp waves in EEG finding is statistically significant. These were found to be a predictor for presence of co-morbid ADHD diagnosis in children with enuresis by logistic regression analysis.
Enuresis only group showed high incidence of focal slow or sharp waves in fronto-temporal region, while focal sharp waves in the temporal region were found mostly in the ADHD control group, these findings were mainly on the left side. These results were supported by a study, which found that most cases of children who presented with attention deficit hyperactivity disorder, enuresis, and breath-holding spells had abnormal generalized or focal sharp waves predominantly in the left hemisphere in most patients [26]. This suggests that epileptiform activity in non-epileptic children might reflect age-dependent mechanisms of brain dysfunction. It is possible that global CNS maturation delay may be a contributor to enuresis. This was proved by Hunsballe JM, who noticed that progressive maturation of bladder stability occurs in conjunction with EEG findings suggest increased CNS recognition of bladder fullness and the ability to suppress the onset of bladder contraction, which improves with increasing of age [27]. The same was reported in study by Hashem S, while it was contradicted by study of Morohongo et al. who found that only half of the children with ADHD had abnormal epileptiform discharges in EEG findings [28, 29].
It was found that the co-morbidity between enuresis and ADHD worsen the self-esteem level, although there was no statistical difference between both groups of enuresis which means that enuresis had its own negative impact on self-esteem regardless of the ADHD diagnosis. This was supported by a previous study of Mellon MW et al. [9].
Regarding the impact of enuresis and ADHD on children’s behavior, “enuresis only” group showed only a significant increase in anxious-shy and psycho-somatic subscales, which can be explained by feeling of shame due to fear from being discovered by others, which makes the child distressed and shy. While in the control ADHD group, there is a statistical increase of learning disability. This could be explained by presence of ADHD diagnosis, in which the core symptoms of inattention, hyperactivity, and impulsivity have a direct negative impact on the learning process.
In this study, it was clear that enuresis with ADHD showed higher levels of behavioral problems and lower levels in self-esteem scores.
