Behavioural and emotional problems in early-treated adolescents with phenylketonuria in comparison with diabetic patients and healthy controls

Even early-treated patients with phenylketonuria (PKU) have a higher risk o f psychosocial maladjustment. This study was performed to determine whether emotional and behavioural problems are specific in phenylketonurics and wh ether they depend on the quality of biochemical control. This comparative s tudy covered 42 PKU patients aged 10-18 years (mean 14.7 years) and 42 diab etic patients matched for sex, age and socioeconomic status. Patients' grou ps were compared with a control sample of healthy controls (n = 2900) from an epidemiological study. We used the Child Behavior Check List (CBCL) acco rding to Achenbach, intelligence quotient (IQ) test according to Weiss, and monitoring of blood phenylalanine concentrations and HBA1 concentrations. Internalizing problems such as depressive mood, anxiety, physical complaint s or social isolation were significantly elevated in both phenylketonuric a nd diabetic patients, whereas externalizing problems were not. The two pati ent groups did not differ significantly either in the degree or in the patt ern of their psychological profile. In both groups no significant correlati ons could be computed between the psychological characteristics and the bio chemical control, the IQ, and the socioeconomic status. No patient was unde rgoing psychiatric treatment or psychotherapy. Our results strongly support a psychological perspective for the development of behavioural and emotion al problems in both phenylketonuric and diabetic patients. Thus, medical tr eatment should be accompanied by psychological support for the families.