The physiological function of the bladder and lower urinary tract (LUT) evolves along with a child’s growth. Normal bladder and urethral sphincter development are crucial for the central and voluntary control of urination. By age 5, this milestone is expected to be achieved through maturational processes.1 According to the International Children’s Continence Society (ICCS), overactive bladder (OAB) is characterized by symptoms such urinary urgency, increased frequency of urination, and nocturia. The diagnosis is typically based on the exclusion of urinary tract infection and other diseases that could cause similar symptoms.2,3 The prevalence of OAB in the pediatric population ranges between 5% and 12% in young children, gradually decreasing to around 0.5% among adolescents aged 16–17 years.4 Children with OAB usually have detrusor overactivity, and the most common symptom is frequent urination (85%), followed by urgency (54%) and incontinence (36%). These urinary symptoms can lead to social withdrawal and psychological stress in affected children.5 Underactive bladder (UAB), on the other hand, is a cause of lower urinary tract dysfunction (LUTD) whose prevalence increases with age. It is characterized by detrusor underactivity with reduced strength and/or duration of urination, leading to an inability to fully empty the bladder.6 Clinically, it is associated with low voiding frequency during the day and/or significant residual urine volumes. Underactive bladder is frequently identified through observation of abnormal detrusor function on urodynamic testing. The flow pattern may be plateau-shaped; and pressure flow studies can differentiate it from bladder outlet obstruction.3

Recent research on the pathophysiology of OAB has shifted from bladder-centric theories to cortical-focused theories.7 One hypothesis suggests that in childhood, the cortical mechanism that suppresses detrusor muscle activity does not immediately reach maturity, delaying the emergence of normal adult-style voiding.8 This maturational delay entails that detrusor hyperactivity will persist until cortical inhibition mechanisms are fully functional, resulting in high-pressure voiding.7,8 The role of cortical development in the pathophysiology of OAB in children is further supported by evidence that some children with resistant OAB also exhibit neuropsychiatric conditions such as attention-deficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), or panic disorder.9–11 To date, few studies have been published regarding the presence of psychiatric symptoms in children diagnosed with underactive bladder.

In brief, the relationship between bladder dysfunction and psychiatric disorders remains unclear. Therefore, we designed a study to explore the presence and nature of psychiatric symptoms in children diagnosed with overactive bladder (OAB) and underactive bladder (UAB). Specifically, the objectives were to analyze the prevalence and severity of externalizing symptoms (eg, attention-deficit/hyperactivity, behavioral problems) and internalizing symptoms (eg, anxiety, depression, emotional difficulties) in these patients. In this context, we formulated the following hypotheses: (1) In children with a diagnosis of OAB, the levels of externalizing problems—such as inattention, hyperactivity, and conduct-related issues—will be significantly higher compared to both children with UAB and healthy controls. (2) Children with OAB will also exhibit higher levels of internalizing symptoms—such as anxiety and depressive features—compared to children with UAB and controls. These hypotheses are grounded in emerging neurodevelopmental theories that link OAB in children to delayed cortical maturation, particularly in areas involved in inhibitory control and emotional regulation. Furthermore, we aimed to address a gap in the current literature by including a comparative analysis of psychiatric symptoms in children with OAB, an area that has received limited attention in research to date.

The sample included 53 children with overactive bladder (OAB), 23 with underactive bladder (UAB), and 30 healthy controls. There were no significant differences between the three groups in terms of age, sex, socioeconomic status, and years of schooling (Table 1).

As expected, uroflowmetry findings differed significantly between the OAB and UAB groups. Children with UAB exhibited significantly longer flow times, voiding times, and higher voided volumes (P < .001). However, there were no significant intergroup differences in average flow rate or delay time in voiding (Table 2).

There were significant differences between groups in several SDQ subscales. Children in the OAB group had significantly higher scores in conduct problems, hyperactivity/inattention, externalizing problems, and total difficulties compared to both the control and UAB groups (P < .005). We found no significant differences between groups for emotional symptoms, peer relationship problems, prosocial behavior, or internalizing problems (Tables 3 and 4).

Finally, there were no significant differences among the groups in any of the RCADS anxiety or depression subscales, including separation anxiety, generalized anxiety, panic disorder, social anxiety, obsessive-compulsive disorder, and major depressive disorder (Table 5).

In this study, screening for psychiatric symptoms in children diagnosed with OAB and UAB revealed that children with OAB had externalizing symptoms more frequently, with no differences between the groups in anxiety and depressive symptoms.

The literature highlights a frequent co-occurrence of lower urinary tract dysfunction (LUTD), such as OAB, nocturnal enuresis, or UAB, and mental health problems like low self-esteem, attachment-related problems, depression, anxiety disorders, and attention-deficit/hyperactivity disorder (ADHD).9–11,16 Many studies focus on the association between nocturnal enuresis and ADHD, consistently reporting higher frequencies of ADHD among children with nocturnal enuresis.17–19 Niemczyk et al. also reported that 14.5% of children with a diagnosis of monosymptomatic nocturnal enuresis exhibited externalizing problems.20 Several studies have documented a co-occurrence rate of 10.5%–21% between ADHD and daytime urinary incontinence in children.18,21,22 Furthermore, Özen et al. found that 29.4% of 156 children with a diagnosis of LUTD of any kind had a psychiatric comorbidity, and the authors suggested that the combined use of psychiatric screening scales and bladder diaries could be beneficial.18 Recent consensus-based reviews further emphasize that psychological comorbidities are consistently more frequent in patients with LUTD across the lifespan, and that complex neurodevelopmental models may better explain these associations than simple unidirectional causation.23 While there is a recognized association between LUTD and psychiatric disorders, the underlying pathophysiology of this association is complex and remains unclear. Furthermore, treating comorbid psychiatric conditions has been found to improve adherence to treatment for LUTD.18 Although the exact mechanisms remain unknown, recent findings indicate that methylphenidate, a common ADHD medication, can increase bladder capacity and voided volume, potentially due to its effects on the dopaminergic and noradrenergic systems.24 Studies examining psychiatric symptoms in children with UAB are notably scarce in the literature. A distinguishing feature of our study is the comparative analysis between OAB, UAB, and control groups. In agreement with the previous literature, we found that children with OAB had significantly higher SDQ externalizing problem scores. The internalizing problems scores in the SDQ did not differ significantly among the three groups. Of note, the relative rarity of externalizing symptoms in the UAB group suggests that psychiatric associations may not apply uniformly to all LUTD subtypes. Most previous studies have analysed heterogeneous samples of patients with LUTD without distinguishing between OAB and UAB, which may obscure potential subtype-specific differences.

Externalizing disorders encompass diagnoses such as oppositional defiant disorder, conduct disorder, or ADHD.25 Research on the etiology of externalizing problems has identified differences in cortical thickness between the posterior region and frontal lobes, indicating delayed cortical maturation.26 Bladder control similarly depends on the maturation of cortical inhibitory networks that suppress detrusor activity through prefrontal-pontine pathways. Contemporary models propose that shared neurobiological mechanisms, including delayed maturation of inhibitory control circuits and stress-regulation systems, may contribute to the co-occurrence of LUTD and psychiatric symptoms.23 In children, OAB may be associated with delayed maturation of cortical inhibitory control networks, potentially linking urgency symptoms with externalizing behaviors through shared frontostriatal and prefrontal regulatory mechanisms. In addition, altered stress regulation, including possible HPA-axis dysregulation, may further contribute to the co-occurrence of behavioral problems and detrusor overactivity, whereas the etiology of UAB may rather involve peripheral or sensorimotor mechanisms.23 Within this framework, it is conceivable that immature executive control mechanisms could contribute both to behavioral dysregulation and to the urgency symptoms observed in OAB. However, as our study did not include neuroimaging or neurophysiological measures, this interpretation should be considered hypothesis-generating rather than confirmatory. Emerging hypotheses regarding the pathophysiology of OAB are consistent with this neurodevelopmental perspective. Future studies incorporating neuroimaging would be valuable to further explore this hypothesis. In contrast, UAB is characterized by reduced detrusor contractility or altered bladder sensation, mechanisms that may involve peripheral or sensorimotor pathways to a greater extent than cortical inhibitory dysfunction. This pathophysiological distinction may partly account for the low frequency of externalizing symptoms in the UAB group. However, although our findings suggest potential neurobehavioral differences between OAB and UAB, they should be interpreted cautiously in light of the relatively small subset of patients with UAB and the lack of performance of uroflowmetry in the control group, which may limit the exclusion of subclinical voiding dysfunction.

The prevalence of LUTD is increasing, impacting the quality of life, sleep, and psychological wellbeing of both children and adults. Studies have demonstrated a bidirectional relationship between LUTD and anxiety and depression.27 Similarly, recent studies emphasize associations between OAB and stress and environmental factors.28 Some studies suggest that anxiety and depression may be risk factors for OAB, and serotonergic or anticholinergic medications could potentially alleviate OAB symptoms.29 In one study from a urogynecology clinic, 26.2% of women who received a diagnosis of OAB were also diagnosed with an anxiety disorder, and the authors recommended screening for anxiety symptoms in OAB patients.28 Most prior studies have focused on adult populations, which may partly explain the discrepancies with pediatric findings. Adult-based research more frequently reports associations with internalizing disorders, whereas pediatric research finds externalizing symptoms more consistently.23 Developmental differences may therefore account for the absence of significant anxiety and depressive symptoms in our pediatric sample. It is possible that behavioral problems are earlier signs of vulnerability, whereas internalizing symptoms may become more prominent later in adolescence or adulthood. Given the limited number of pediatric studies, our investigation addressed this gap by assessing anxiety and depressive symptoms specifically in children with OAB and UAB. In our cohort, we found no differences in either RCADS anxiety and depression subscale scores or SDQ internalizing problems scores between the groups, indicating consistency across emotional symptom measures. The divergence from the predominant findings in adults may therefore reflect developmental stage differences rather than a true absence of psychological vulnerability.

From a clinical standpoint, consensus recommendations propose routine psychological screening in patients with LUTD.23 Our findings support this approach, particularly in children with OAB, in whom externalizing symptoms may be more prevalent. Furthermore, there is evidence that LUTD can have a psychosocial impact at family level, with a correlation between caregiver emotional distress and child behavioral problems.30 Therefore, a multidisciplinary evaluation addressing both urological and psychosocial domains may be beneficial.

Our study was conducted in a single center, and the number of children diagnosed with underactive bladder (UAB) was relatively small. Consequently, multicenter studies with larger samples are needed to corroborate these findings. Additionally, uroflowmetry was not performed in the control group, which may limit the exclusion of subclinical voiding dysfunction, although controls were carefully screened and reported no lower urinary tract symptoms. Furthermore, various scales are available for psychiatric evaluation, and we believe that using self-report scales for differential diagnosis of externalizing problems, such as ADHD, oppositional defiant disorder, and conduct disorder, could be beneficial for a more comprehensive assessment.

In this study, we observed that children with OAB had higher externalizing problems and total scores on the SDQ, which screens for general psychiatric symptoms, compared to the other groups. The SDQ scores of children with UAB, however, were similar to those of healthy controls. There were no significant differences between the three groups in the RCADS scores, which measures symptoms of anxiety and depression. These findings suggest that psychiatric symptom profiles in pediatric LUTD may vary according to the type of dysfunction, with externalizing symptoms more strongly associated with OAB than with UAB. The observed pattern raises the possibility that OAB and UAB differ not only in urodynamic characteristics but also in their neurodevelopmental and neurobehavioral correlates. It is reasonable to assume that immature inhibitory control networks and altered stress-regulation mechanisms may contribute to both behavioral dysregulation and detrusor overactivity in OAB. However, given the cross-sectional design of our study, these interpretations should be considered hypothesis-generating rather than confirmatory. Longitudinal studies incorporating neuroimaging, neuropsychological assessment, and biological stress markers are needed to clarify potential causal mechanisms and developmental trajectories. From a clinical perspective, our findings support the value of psychiatric screening—particularly for externalizing symptoms—in children with bladder dysfunction as part of a comprehensive and multidisciplinary approach to their management.

The study was designed by GYT, HD and GT; GYT, AC and HD collected data; GYT and HFA contributed to the analysis and interpretation of the data; GYT, HFA and GT drafted the article and revised it. All authors read and approved the final manuscript.

We did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors for this research.