Enuresis, ADHD and BDNF: A Narrative Review of the Hypothesized Interconnections and Potential Triplet Relationship.

Attention-deficit/hyperactivity disorder (ADHD), brain-derived neurotrophic factor (BDNF), and enuresis are interconnected in several ways, primarily through their potential links to neurodevelopmental factors and brain function. ADHD is considered a neurobehavioral and neuropsychiatric condition characterized by numerous comorbidities, and it represents one of the most frequently encountered neuropsychiatric disorders in clinical practice. Enuresis constitutes a subgroup of intermittent incontinence occurring during sleep that can be further subdivided into monosymptomatic (MNE) and non-monosymptomatic enuresis (NMNE). BDNF plays a crucial role in neurodevelopment, including neuronal growth, proliferation, survival, differentiation, and synaptic plasticity. This narrative review synthesized available literature identified through a systematic search of PubMed/MEDLINE, Science Direct, and Scopus databases (January 2000-December 2025). However, the evidence base is heterogeneous, and findings regarding BDNF in ADHD are inconsistent. Studies examining BDNF in enuresis often involve urinary BDNF, which reflects local bladder production rather than central BDNF activity. Further research is needed to clarify the specific roles of BDNF in the development and manifestation of these conditions and to fully elucidate the complex relationship between BDNF, ADHD, and enuresis.