LAUSR

BACKGROUND Evidence suggests that physical and mental illnesses are strongly correlated in children. This study examined patterns of the chronicity of multimorbidity (co-occurring physical and mental illness); estimated homotypic continuity; and modelled factors associated with chronicity in children newly diagnosed with a chronic physical illness. METHODS Children aged 6-16 years diagnosed with one of asthma, diabetes, epilepsy, food allergy, or juvenile arthritis were recruited from two children's hospitals and followed for 6 months. Child mental illness was measured using the parent-reported Mini International Neuropsychiatric Interview and Ontario Child Health Study Emotional Behavioural Scales at baseline and 6 months later. Children were stratified into three groups: no multimorbidity, acute (multimorbidity at only one assessment), and persistent (multimorbidity at both assessments). RESULTS Forty-nine children were available for analysis: no multimorbidity (n = 18), acute (n = 13), and persistent (n = 18). Homotypic continuity was highest for conduct disorder (67.5%) and lowest for major depression (16.7%). Unadjusted analyses showed positive associations between child and parent behavioural symptoms, as well as family functioning with persistent multimorbidity. These associations remained after adjustment, ranging from odds ratio (OR) = 1.29 [1.01, 1.64] for depression to OR = 1.61 [1.11, 2.33] and OR = 1.61 [1.10, 2.35] for attention-deficit hyperactivity and oppositional defiant, respectively, in child models. In parent models, associations remained for parental anxiety (OR = 1.18 [1.04, 1.34]) and stress (OR = 1.15 [1.02, 1.31]). CONCLUSIONS Multimorbidity is persistent in children newly diagnosed with physical illnesses, regardless of the mental comorbidity experienced. Integrating family-centred mental health services soon after the diagnosis of a physical illness should be prioritized in pediatric settings.