DEVELOPMENT OF A SCALE TO MEASURE SYMPTOMS OF ANXIETY AND DEPRESSION IN THE GENERAL UK POPULATION - THE PSYCHIATRIC SYMPTOM FREQUENCY SCALE

Objectives-The psychiatric symptom frequency (PSF) scale was developed to assess symptoms of anxiety and depression (ie affective symptoms) experienced over the past year in the general population This study ai med to examine the distribution of PSF scores, internal consistency, a nd factor structure and to investigate relationships between total sco res for this scale and other indicators of poor mental health. Partici pants-The Medical Research Council national survey of health and devel opment, a class stratified cohort study of men and women followed up f rom birth in 1946, with the most recent interview at age 43 when the P SF scale was administered. Main results-The PSF scale showed high inte rnal consistency between the 18 items (Cronbach's alpha=0.88). Ratings on items of the scale reflected one predominant factor, incorporating both depression and anxiety, and two additional factors of less stati stical importance, one reflecting sleep problems and the other panic a nd situational anxiety. Total scores were calculated by adding 18 item s of the scale, and high total scores were found to be strongly associ ated with reports of contact with a doctor or other health professiona l and use of prescribed medication for ''nervous or emotional trouble or depression,'' and with suicidal ideas. Conclusions-The PSF is a use ful and valid scale for evaluating affective symptoms in the general p opulation. It is appropriate for administration by lay interviewers wi th minimal training, is relatively brief, and generates few missing da ta. The total score is a flexible measure which can be used in continu ous or binary form to suit the purposes of individual investigations, and provides discrimination at lower as well as upper levels of sympto m severity.