H Murphy, K Lloyd
depression, gender, mental health, morbidity, risk factors
H Murphy, K Lloyd. Gender as a risk factor in minor psychiatric morbidity in the United Kingdom. The Internet Journal of Epidemiology. 2008 Volume 6 Number 2.
Previous research has found consistent differences in psychiatric morbidity for men and women across continents. The current research focuses on rates of minor psychiatric morbidity (MPM) across the United Kingdom for the first time, examining gender and exploring region as influencing factors in prevalence rates. We found that while there was no influence of region on psychiatric health, women had significantly higher mean GHQ-12 scores, and thus poorer mental health, than men across the UK (t=12.77, p<.001). We discuss this finding in the context of debates which point to biological, psychosocial and sociocultural factors explaining differences in symptom prevalence and outline the impact the UK results have in handling MPM in clinical and national health settings.
The GHQ-12 is a widely used questionnaire detecting psychiatric disturbance in the general population and GHQ-12 data were obtained from Wave 13 of the BHPS and Wave 3 of the NIHPS. Data are weighted cross-sectionally to ensure the sample is representative of the population in that year and the appropriate cross-sectional weight variables computed for 2003 were used to analyse the data set for this paper.
In 2003, 14,761 respondents from all UK regions (England, Scotland, Wales and Northern Ireland) completed the GHQ-12. Respondents were asked to rate their general level of wellbeing in the period of a few weeks before the interview. GHQ-12 scores were coded in two ways for analysis. Firstly, the 12 individual items were coded 0,1,2,3 and the scores were summed to give an overall GHQ-12 scale running from 0 (the least distressed) to 36 (the most distressed). Higher mean scores are indicative of psychiatric disorder. Secondly, values of 1 and 2 on each item were re-coded to 0, and 3 and 4 values to 1. The items were then summed to give a scale running from 0 (the least distressed) to 12 (the most distressed). A threshold score of 4 or more on the GHQ-12 is often used to identify respondents with a potential psychiatric disorder or ‘caseness' and this cut-off point was used for the purposes of the present paper.
Mean GHQ-12 scores
The data were analysed using the procedure for complex surveys in STATA version 8. As Table 1 shows, the mean GHQ-12 score for the UK as a whole was 11.02. There were no significant differences in GHQ-12 scores across the four regions of the UK. However, consistent with previous research using the GHQ as a measure of mental health, women had significantly higher mean GHQ-12 scores, and thus poorer mental health, than men (t=12.77, p<0.001).
One in five (19.33%) respondents in the UK had GHQ-12 scores indicative of psychological distress on the GHQ-12. As expected, there was a statistically significant relationship between gender and GHQ-12 caseness; more women (22.64%) than men (15.62%) had a score of 4 or more (p<0.001).
While no effect for region was found, gender differences in psychiatric morbidity in the UK parallel research findings in Europe and North America.[6,7,8,9] There is also longitudinal evidence to suggest that women tend to have longer and more chronic periods of psychiatric distress as well as experiencing higher rates of co-morbidity which lead to worse outcomes.
The causes of gendered MPM are still under debate and theorists have pointed towards biological, psychosocial and sociocultural factors to explain differences in symptom prevalence. Reproductive function in women may be linked to depressive episodes over a woman's life cycle. Pre-menstrual mood fluctuations, pregnancy, the post-partum period, the menopause and exogenous hormone therapy across the life span have been presented as physical and psychological stressors not experienced by men. Recent research suggests that serotonergic mechanisms, associated with the aetiology of major depression and anxiety, differ between the sexes but in the same year, a critical review of gender differences in rates of depression, found no evidence to support either a hormonal or biological causal mechanism. [12,13]
Alternatively, gender socialization theory highlights the different ways in which personal distress is displayed and experienced for each gender. Girls and women tend to internalize distress while boys and men tend to externalise personal distress. [14,15] Internalization is then associated with disorders such as depression, anxiety and suicidal ideation while externalisation is associated with anti-social behaviour, substance use, addiction and suicide. This is not to say that the underlying factors producing psychiatric distress in each gender are different but that there appears to be specifically socially determined ways of expressing personal distress for each gender. Depressed women and alcoholic men may be more acceptable compared to alcoholic women and depressed men in society.
However, gender based social roles do not appear to explain differences in common mental disorders according to recent research in the UK and a recommendation to examine gendered role demands and conflicts in a more detailed and systematic manner was suggested. This would produce more local and context sensitive data and is more easily achieved with the use of qualitative research methodologies. Of course, the issue here is the tension between the analysis of large epidemiological data sets, the setting and testing of theory and, ultimately, the search for causation. There is also a continuing problem with a lack of harmonisation as regards the choice of clinical measures and this cuts within and across the national and international context. In short, this has left us with clear findings about gendered MPM but little resolution to ascertaining causal factors.
While theoretical debates continue, it is crucial that clinicians and community healthcare teams are aware of gender as a primary risk factor for MPM and that health professionals develop awareness and appropriate response measures to robust but often under-acknowledged findings. Depressive and anxiety disorders are the leading cause of mental disability in WHO's global burden of disease and these particular disorders are encountered on a daily basis in community and primary care settings.[18,19] Two caveats accompany this research paper. Firstly, brief screening scales usually contain items that assess somatic symptoms, depression, anxiety or distress – symptoms which have a higher incidence in women and which are correlated with help-seeking behaviour. Secondly, women clients tend to be