POSSIBLE EFFECTS OF TETRAHYDROBIOPTERIN TREATMENT IN 6 CHILDREN WITH AUTISM - CLINICAL AND POSITRON EMISSION TOMOGRAPHY DATA - A PILOT-STUDY

Six children, between 3 and 5 years of age, having infantile autism ac cording to DSM-III-R, were treated for 3 months with 6R-L-erythro-5,6, 7,8-tetrahydrobiopterin (R-BH4), a cofactor for tyrosine hydroxylases in the biosynthetic pathway of catecholamines and serotonin. A criteri on for inclusion in the studs was a relatively low level of R-BH4 in t he cerebrospinal fluid. For clinical evaluation, the Parental Satisfac tion Survey (PASS) was used every fourth week and the Griffiths Develo pmental Scales were used before starting and a months after completing the treatment, During the treatment period, all parents reported impr ovements in the child's social functioning - mainly eye contact and de sire to interact - and in the number of words or sounds which the chil d used. Small positive changes were noted on the Griffiths Development al Scales between the two testing occasions, R-BH4 levels in CSF incre ased significantly after treatment, The positron emission tomography ( PET) study showed that the high value of dopamine Da receptor binding in the caudate and putamen decreased by about 10% towards the normal l evel after treatment with R-BH4, The observations in this open study i ndicate that the drug might be useful for a subgroup of children with autism, but there is a need for a larger double-blind study with a lon ger treatment period.