Background to the Research

• This was the first in-depth study of psychiatric morbidity in NI. The aim of the study was to report the prevalence of psychiatric disorder and the needs for treatment in the population aged 18-64 years in Derry. The combination of the Troubles and social deprivation made Derry a suitable place to test the relationship between adverse social environments, deprivation and mental illness, as well as to test the need for services.
  

Research Approach

• Fieldwork was carried out during February 1993 to September 1994, which overlapped with the date of the first Peace Agreement in NI.
• The sample frame was the electoral roll for the District of Derry.
• 1242 people were selected using systematic sampling. Four wards were over-sampled as their particular socio-economic characteristics would allow more detailed analysis of the interactions between psychiatric morbidity and social deprivation, social isolation and social deprivation.
• All respondents were asked to complete a questionnaire including socio-demographic information and the GHQ-28. The GHQ-28 was scored using the 0,0,1,1 scoring method, with scores of 5 indicating possible cases of psychological morbidity.
• Those respondents aged less than 65 years who scored 5 or more on the GHQ-28, as well as one in five of those below the cut-off, were asked to take part in the second stage. This involved interviews in the respondent's home using the SCAN (Version 1.0). From this, diagnoses were generated according to ICD-10 and the DSM-III-R. The interview related to the present state (one month before interview), and representative episode (symptoms that had been present in the previous year but were no longer present or were not as severe).
• The interview also included the community version of the Medical Research Council Needs for Care Assessment, which allowed comparisons with other research.

Main Findings

• 1088 respondents returned questionnaires in the first stage, including 161 aged 65 years or over.
• 227 out of the 304 respondents scoring 5 or more on GHQ-28 were interviewed, along with 80 respondents scoring less than 5.
• The socio-demographic characteristics of the sample reflected the high rates of unemployment and poverty in the area. For example, social security benefits were received by 51.5% of respondents, and 32.2% of respondents lived in households solely dependent on benefits.
• The 1-month prevalence rate of an ICD-10 disorder was 7.5%, with a 1-year prevalence rate of 12.2%.
• There were no statistically significant male/female differences for the 1 month prevalence rates for individual groups of disorders.
• The total morbidity rate for 1-year prevalence was higher for females (14.4%) than males (9.1%).
• The 1-month total morbidity rate for females (7.8%) was similar to that for males (7.1%).
• Depressive illness was considerably more common in females than in males, especially in 1-year prevalence rates (8.5% female, 2.7% male). This may explain the higher overall 1-year prevalence in women.
• Anxiety disorders were also more common in females than males.
• Only one quarter of needs for treatment were met, and only half of participants who attended services had their needs met.

Comparisons with other surveys

• The first British National Surveys of Psychiatric Morbidity reported a prevalence of depressive episode of 2.1%, and 2.9% in the second (2.4% in Derry). However, the methods within these surveys may over-identify depression. Thus the Derry value is likely to be genuinely greater than the UK average.
• Gender differentials for depressive disorders and anxiety disorders were more pronounced in Derry than in British surveys.
• While alcohol and drug dependence were identified more frequently in Derry than in a comparable survey for a deprived inner-city area of London (Camberwell), figures from both surveys were low.
• Data for needs of care were similar to those in Camberwell. In both areas, there seems to be better provision of treatment for depression than for anxiety.
• Respondents to the Derry and British survey were reluctant to present themselves for treatment, and so there is a need for education to encourage them to do so.