This study shows a high rate of symptoms consistent with ADHD during childhood in parents of children affected by this disorder.
Several aspects are involved in the multi-factorial pathogenesis of ADHD, including genetic, neurobiological and environmental elements. Inheritance likely plays a fundamental role in pathogenesis: the assessment of its weight would allow not only a better understanding of the disease but also an early diagnosis in the children of affected parents, along with timely treatment and prevention of detrimental consequences. Remarkably, a positive family history may be a relevant diagnostic clue, which physicians should specifically address. On the other hand, parent training is a cornerstone of treatment for children with mild-to-moderate ADHD [15]. Since parental ADHD may particularly impair parenting and family functioning, hindering the ability to deal with affected children, identifying affected parents could be a clue to optimize patients’ outcomes [16, 17].
In this study we found a significant association between kinship and parents’ WURS test positivity: in particular, 49.1% of fathers and 30.0% of mothers of ADHD patients, compared to 1.7% of fathers and 1.7% of mothers of non-ADHD patients, had a positive test, reporting features consistent with ADHD during their childhood. Remarkably none of the surveyed parents had ever been diagnosed with ADHD, underlying a lack of standardized diagnostic criteria to detect this condition in the past. However, the WURS test does not allow the retrospective diagnosis of ADHD: indeed, its aim is to highlight the presence of emotional and behavioural traits consistent with the disorder.
These results are in line with the previous literature. The role of genetic factors has been assessed over time [8] , and it has been confirmed by the high concordance between twins [3, 9, 11]. Bidwell demonstrated a four-time higher risk of developing ADHD in children with affected parents or first-degree relatives, compared to the general population [12]. Previous studies relied on the WURS test to assess symptoms suggestive of ADHD during childhood in parents of affected children. Starck and colleagues found a WURS test positivity in 49.1% of fathers and 27.3% of mothers of ADHD patients [18]: compared to the above mentioned survey, our study was powered by the analysis of data from a control group and by the comparable number of enrolled fathers and mothers, which allowed us to stratify the weight of familiarity by the sex of affected parents. Moreover, to our knowledge, this is the first study that separately examined the school and emotional impairment of parents during their childhood, through a specific sub-analysis of the scores obtained in the specific test questions addressing these issues.
Regarding school performances, we found an association between reported parents’ school difficulties and WURS test positivity, confirming the pivotal role of undiagnosed and untreated ADHD in learning difficulties. The latter, as underlined by Marzocchi and colleagues [7], can be explained in the light of a vicious circle between the deficit of self-regulation cognitive processes and the inability to adopt effective organizational and executive strategies appropriate to the task. This profile negatively affects the performance in the comprehension of written texts, studying, and resolution of arithmetic problems [19, 20]. In this study, we found that mothers with positive tests showed higher scores in the questions investigating school impairment, compared to fathers testing positive. This issue could further demonstrate that in females with ADHD, inattention is usually preponderant compared to hyperactivity, negatively affecting academic performances.
Similar results were found about emotional deregulation. Parents with an overall positive WURS test demonstrated higher scores in the questions assessing emotional lability, compared to parents with negative tests.
Tabassam and Grainger widely described the emotional dysfunction in ADHD children, characterized by sudden emotional changes, dysphoria, irritability, low tolerance to frustration, emotional hyper-reactivity, and emotions-recognition deficits [21]. The concurrent effect of the critical judgment of families, teachers, and peers, easily led to low self-esteem, sense of social rejection and loneliness, which in turn can promote the development of further psychopathologies, such as mood disorders. By stratifying data by gender, we found that the mothers tested positive displayed a higher median score compared to positive testing fathers, underlying the central role of emotional lability within the disorder in females. In a longitudinal study involving 140 children diagnosed with ADHD, Hinshaw found that female subjects had more severe anxiety, depressive symptoms, and more significant difficulties in daily functioning compared to males [22]: at ten years follow-up, girls with ADHD were more likely to display self-injuring behaviours and suicide attempts compared to boys.
This study, not only confirms these data but also highlights a high occurrence of school and emotional impairment in parents of affected children during their childhood, strengthening the suitability of the WURS test for the retrospective assessment of symptoms suggestive of ADHD, considering the crucial role of these two aspects in the diagnosis of the disorder.
The main limits of this study consist of the relatively small sample size and the lack of a correlation analysis between patients and parents, due to the choice to collect and investigate the results in a completely anonymous way. For the same reason, we assessed every parent independently; therefore, it was not possible to compare the association with an affected child with a single positive parent and both parents’ positivity. On the other hand, the guarantee of anonymity provided a parental participation rate of almost 100%, which in turn, represents the strength of this study. A further point of strength was the case–control design, which allowed additional comparative results.