Background. There have been six randomized controlled trials of psychological therapy with
generalized anxiety disorder (GAD) using DSM-III-R and DSM-IV. All have used the Trait version
of the Spielberger State–Trait Anxiety Inventory (STAI-T) as one of several outcome measures.
Each study, however, employed different methods of calculating the clinical significance of
outcomes making it difficult to reach a balanced appraisal of the efficacy of psychological treatment.
Methods. Raw data on STAI-T scores at pre-, post- and follow-up were obtained for each of the six
studies (total N=404). Jacobson methodology for defining clinically significant change (criterion
c, reliable change index = 8, cut-off point = 46) was used to allocate each patient to one of four
outcomes: worse, unchanged, improved and recovered. The proportion of patients in each category
was calculated for treatment conditions in each study and also for aggregate data across types of
Results. A recovery rate of 40% was found for the sample as a whole with 12 of the 20 treatment
conditions obtaining very modest recovery rates of 30% or less. Two treatment approaches –
individual cognitive behavioural therapy and applied relaxation – do relatively well with overall
recovery rates at 6-month follow-up of 50–60%.
Conclusions. Jacobson methodology, in distinguishing between improvement and recovery on a
standardized measure of general vulnerability to anxiety, provides a stringent but clinically more
meaningful evaluation of the efficacy of psychological therapies with GAD than has been available
hitherto. Systematic focus on either excessive worry or physiological arousal gives worthwhile