Behavioural problems in children and adolescents with spinal muscular atrophy and their siblings

Spinal muscular atrophy (SMA) is a chronic illness characterized by loss of motor function. The aim of the study was to investigate behavioural adjustment in 96 children and adolescents with SMA (47 males, 49 females; mean age 11 years 2 months, range 6 to 18 years). Forty-five non-affected siblings (26 males, 19 females; mean age 11 years 6 months, range 6 to 18 years) and 59 normally developing children (33 males, 26 females; mean age 10 years 8 months, range 6 to 18 years) were recruited as control participants. Behavioural symptoms were measured with the Child Behaviour Checklist (CBCL) and disorders were assessed with a structured psychiatric interview (Kinder-DIPS). Of the patients with SMA, 12.5% fulfilled the criteria for an ICD-10 or DSM-IV diagnosis, with separation anxiety disorder being the most common diagnosis. The CBCL total score was in the clinical range for 11.5% of patients, 20% of the siblings, and 11.7% of the control children; the externalizing score rates were 2.1%, 22.2%, and 11.9% respectively; the internalizing score 18.9%,24.4%, and 13.6% respectively. Comorbid psychopathology was not influenced by sex, IQ, nor severity of SMA, and only externalizing behaviour was correlated to age. In conclusion, children and adolescents with SMA are characterized by a low psychiatric comorbidity not different from control individuals. The group with the highest rate of, behavioural. problems and with the greatest need for intervention were the non-affected siblings who had a two- to threefold higher rate of behavioural problems than the normative population.