Medical (fluoxetine) and psychological (cognitive–behavioural therapy) treatment for premenstrual dysphoric disorder A study of treatment processes Myra S. Hunter*, Jane M. Ussher, Margaret Cariss, Susannah Browne, Rosanne Jelley, Maurice Katz Department of Psychology, University College London, London, UK Received 13 September 2001; accepted 25 January 2002 Abstract Objectives: To investigate (i) the differential changes in premenstrual symptoms, mood, cognitions, and coping strategies during two treatments [cognitive – behavioural therapy (CBT) and fluoxetine] for premenstrual dysphoric disorder (PMDD) and (ii) the characteristics of those with good vs. poor outcome post treat- ment and at 1 year follow-up. Methods: Premenstrual symptoms, mood (Hospital Anxiety and Depression Scale, HADS), causal attributions, and use of cognitive and behavioural coping strategies were examined during 6 months of both treatments. The two treat- ment groups were then combined and divided on the basis of good vs. poor outcome posttreatment and at 1 year follow-up. Baseline measures were used to predict posttreatment outcome, and baseline and posttreatment measures were examined when attempting to predict outcome at 1 year follow-up. Results: Both treatments were equally effective at the end of 6 months (prospective daily diary measure). Fluoxetine treatment had a more rapid effect and greater impact upon anxiety symptoms, while CBT was associated with increased use of cognitive and behavioural coping strategies and a shift from a biomedical to a biopsychosocial causal attribution of premenstrual symptoms. Depressed mood at baseline assess- ment was associated with poorer response to both treatments, and learning active behavioural coping strategies was associated with a good outcome at 1 year follow-up. Conclusion: These results provide evidence of differential treatment effects of fluoxetine and CBT for PMDD and offer information that will enhance clinical decision-making. D 2002 Elsevier Science Inc. All rights reserved. Keywords: Cognitive– behavioural therapy; Premenstrual symptoms; Process; Psychological; SSRIs; Treatment Introduction Both pharmacological and psychotherapeutic treatments have been found to be effective in the treatment of a number of psychological disorders, such as major depression [1,2] and panic disorder [3], as well as problems presenting with both physical and psychological symptoms, such as chronic fatigue [4], postnatal depression [5], and premenstrual syndrome [6,7]. In several of these studies, antidepressants and cognitive – behavioural therapy (CBT) have been com- pared, and while in general comparable effects have been found, differential effects have also been noted, for example, adverse effects in response to medication and long-term maintenance of improvements. In a recent study, we found that fluoxetine (20 mg daily), a selective serotonin reuptake inhibitor (SSRI), and CBT were both equally effective in the treatment of women with premenstrual dysphoric disorder (PMDD), while a combina- tion of treatments offered no additional benefits [8]. How- ever, at 1 year following the cessation of treatment, significantly more of those having had CBT maintained improvement compared to those having had fluoxetine. We concluded that in the short to medium term, patient pref- erence should guide the choice of treatments. However, in order to understand further the nature of change that occurs with these quite different treatments, the current study was carried out to investigate the process of change both during and following treatment with either fluoxetine or CBT. This information might then increase knowledge about the mech- 0022-3999/02/$ – see front matter D 2002 Elsevier Science Inc. All rights reserved. PII:S0022-3999(02)00338-0 * Corresponding author. Department of Psychology, Adamson Centre for Mental Health, St. Thomas’ Hospital, South Wing, Block 8, Lambeth Palace Road, London SE1 7EH, UK. Tel.: +44-20-7928-9292; fax: +44-20- 7960-5662. Journal of Psychosomatic Research 53 (2002) 811 –817