Thirty-two families were investigated four years after a false alarm in the neonatal screening of their newborns. Sixteen of the families showed signs of persistent anxiety 6-12 months after the screening. Thirteen of them still show anxiety after 4 years. Of the 16 without anxiety at 6-12 months, 6 show signs of anxiety now. This persistent anxiety may be related to the initial psychological trauma of the false positive screening result. Thus, 19 of the 32 families have not completely integrated their experience. Twenty-four children were psychologically evaluated. Eight families refused to have their children examined. Twelve of the children showed disturbed behavior, 10 of these have parents who show unsatisfactory integration. Medical measures have psychological side-effects, which may be interpreted as iatrogenic. However, the effects of an external stress depend on the individual's susceptibility to it and abilities to cope with it and use external support available.