6 APPENDIX A: SOME OTHER RELEVANT STUDIES 3.6.1 Psychiatric morbidity among people of Irish Catholic descent in Britain (1987±88)
This was a longitudinal population-based study of everyday life and health among three cohorts aged 15, 35, and 55 at inception into the study in 1987± 88. This study is referred to as the ``West of Scotland 20±07'' study and was conducted in a large urban area of Glasgow. In 1990±91, 908, 852, and 858 subjects in the three cohorts were followed up. Depression was measured using the self-rating Hospital Anxiety and Depression Scale (HADS)83 to detect possible and probable depression. A conservative cut-off score of 9 or more on the HADS was used to de®ne depression. In this community, those of Catholic religion are considered mostly to be of Irish descent. The authors argue that although recent Irish migrants are uncommon, Catholic inter-marriage maintains a strong Irish heritage. Subjects were classi®ed as of Catholic heritage in the youngest and eldest cohort if one parent was of Irish descent and in the middle cohort if they responded as being born in the Catholic heritage. Reasons for this approach were not speci®ed.