While some studies of primary nocturnal enuresis suggest that it is a symptom of an underlying psychiatric or behavior problem, others suggest that it is a discrete entity requiring only treatment of the bedwetting itself. Friman and colleagues performed a study to evaluate whether a relationship exists between nocturnal enuresis and clinically significant comorbid behavior problems.

Data were collected from three groups: children with nocturnal enuresis who were referred for a behavioral evaluation; children with problem behavior and no enuresis who were referred for a behavioral evaluation (clinical sample); and children without enuresis who were not referred for a behavioral evaluation (nonclinical sample).

Children in the enuresis group were referred to one of two pediatric behavioral clinics, had failed to attain nocturnal continence for any six-month period and had been bedwetting at least once a week before referral. The clinical group was selected from 429 children who were referred to the same two pediatric clinics. The third group was randomly selected from a standardization group of 614 children who were seen at an outpatient pediatric clinic for minor illnesses or well-child care. Each group contained 92 children (62 boys and 30 girls) matched for age and sex. Children ranged in age from five to 13 years (mean age: 7.8 years).

The Eyberg Child Behavior Inventory (ECBI), a standardized parent-report scale that represents 36 common childhood behaviors, was used to assess each child. This instrument yields a problem intensity score and a problem number score, and has been well documented as an assessment tool for childhood behavior characteristics.

Children referred because of behavior problems (the clinical group) were found to have mean problem number and problem intensity scores significantly higher than those of the enuresis and the nonclinical groups. The authors also calculated the number of problem intensity and problem number scores that fell above the clinical cutoffs. At least one ECBI score above the clinical cutoff was present in 38 (61 percent) of the 62 boys and in 18 (60 percent) of the 30 girls in the clinical group. In contrast, 24 boys (39 percent) and five girls (17 percent) with enuresis had at least one ECBI score above the clinical cutoff. In the nonclinical group, 12 boys (19 percent) and four girls (13 percent) had such scores.

The authors conclude that children with primary nocturnal enuresis do not have significant behavioral comorbidity. They believe nocturnal enuresis is a discrete biobehavioral entity that can be managed by the pediatrician or family physician. Unless the child's clinical presentation is unusual, referral for a mental health evaluation is not necessary.