Youth involvement in substance abuse can be a source of considerable distre
ss for their parents. Unilateral family interventions have been advocated a
s one means by which concerned family members can be supported to assist su
bstance-abusing family members. To date there has been little research exam
ining the impact of unilateral family interventions on the directly partici
pating family members. In this study the early impact of an 8-week parent-g
roup programme known as Behavioural Exchange Systems Training (BEST) was ev
aluated using a quasi-experimental, waiting list control design. The profes
sionally led programme had been developed to support and assist parents in
their efforts to cope with adolescent substance abuse. Subjects were 66 par
ents (48 families) accepted for entry into the programme between 1997 and 1
998. Comparison was made between 46 parents offered immediate entry into th
e programme and 20 parents whose entry to the programme was delayed by an 8
-week waiting list. At the first assessment 87% of parents showed elevated
mental health symptoms on the General Health Questionnaire. Evidence sugges
ted exposure to the intervention had a positive impact on parents. Compared
to parents on the waiting list, parents entered immediately into the inter
vention demonstrated greater reductions in mental health symptoms, increase
d parental satisfaction, and increased use of assertive parenting behaviour
s. Copyright (C) 2001 John Wiley & Sons, Ltd.