ON PREDICTING IMPROVEMENT AND RELAPSE IN GENERALIZED ANXIETY DISORDERFOLLOWING PSYCHOTHERAPY

This paper concerns an investigation of outcome predictors in a clinic al trial of psychological therapies for generalized anxiety disorder. A variety of information of potential predictive value was obtained at three stages of patient contact: the initial referral, st screening i nterview and early sessions of therapy. Three measures of the clinical significance of change over a 12-month follow-up period were used to construct a composite measure which categorized outcome in terms of su stained improvement, relapse and no consistent change. Logistic regres sion was used to examine the validity of predictors identified in prev ious research and the relative importance of data obtained from the th ree different stages. Seventy-one per cent of patients were correctly classified as improved or not from initial data with a significant inc rease in accuracy with information from the screening interview (77 pe r cent) and early sessions (82 per cent). Patients who relapsed or not were predicted with considerable accuracy from initial data (90 per c ent) and there was no significant increase in predictive power with ad ditional information. The most powerful and robust predictors were: ty pe of treatment received, marital status, marital tension and complexi ty of clinical presentation in terms of axis 1 co-morbidity. A concept ual framework for prediction is outlined.