Summary Two hundred and twenty-two women with advanced cancer of the breast were asked to complete two previously validated self-assessment questionnaires (Hospital Anxiety and Depression Scale (HADS) There has been extensive investigation into the psychological sequelae of early breast cancer and its treatment (Maguire et al., 1978;Maguire et al., 1980;Morris et al., 1977;Robert et al., 1972) but there are few data concerning the prevalence of depression and anxiety in patients with advanced disease. There is a need to determine the extent and severity of affective disorder in patients receiving palliative treatment for breast cancer and to find out whether such disorder is transient or warrants intervention. Plumb and Holland (1981) reported that 20-30% of patients admitted to hospital for the treatment of a variety of advanced cancers developed clinically significant depression and 15% had severe anxiety. In a study of 215 cancer inpatients and outpatients Derogatis and co workers (1983) found 47% met criteria for psychiatric disorder, and of these 13% had a major affective disorder, mainly depression. The majority were described as suffering 'adjustment disorder' that is a less severe form of mood disorder. In a number of other studies (Bukberg et al., 1980;Craig & Abeloff, 1974;Farber et al., 1982;Plumb & Holland, 1977) self report questionnaires have been used to assess psychological morbidity in heterogeneous cancer patient groups. Two such questionnaires were deemed suitable for use for the present study. The Hospital Anxiety and Depression Scale (HADS) (Zigmond & Snaith, 1983) was designed to measure depression and anxiety in medical outpatients and avoids the use of somatic symptoms, which may also be attributed to disease and treatment. It has been shown to be a valid measure of the severity of disorders of mood. The Rotterdam Symptom Checklist (de Haes et al., 1990) was designed as a multidimensional scale for use in quality of life assessment: it contains a subscale of eight items relating to psychological symptoms.The authors validated these two questionnaires in a series of 81 patients with advanced breast cancer (Hopwood et al., 1991), to establish appropriate cut-off values for the identification of 'cases' of affective disorder. Both questionnaires identified 75% of patients diagnosed as cases by a psychiatric interview. The scales were able to correctly identify one in evey two high scorers as a case and, although this predictive power was high in relation to 'screening' for affective disorder, it will inevitably mean that prevalence rates using self-rating scales are an estimate of morbidity rather than an accurate measure of disorder. Nevertheless, scales such as the HADS and RSCL are being used increasingly to evaluate 'quality of life' in cancer patients and their Correspondence: P. Hopwood.Received 16 February 1990; and in revised form 2 April 1991.performance in the measurement of psychological disorder in a homogeneous population of patients warrants evaluation.The aim of the study ...