Be vigilant for common mental health disorders

Common mental health disorders (CMHD) affect one in six people in the community. These disorders are even more common in primary care. A New Zealand study found that 20.7% of people presenting to primary care had suffered a CMHD over a 12-month period, compared with 14.8% in the community. Most sufferers do not consult their GP, even when patients do present with symptoms they are often not diagnosed. Only 24% of sufferers in the ONS survey were receiving treatment: 14% medication; 5% counselling or therapy and 5% both. The new NICE guideline on identifying CMHD brings together recommendations on identification, assessment and referral in one place, for easy reference. The NICE depression guidelines recommend that GPs are alert for depression in those with a past history of depression, and in patients with a chronic physical health problem. The GAD and panic guideline also recommends that practitioners look for anxiety disorders in those with chronic physical disorders, plus frequent attenders with multiple functional somatic symptoms, and patients with excessive alcohol consumption.

Multimorbidity, service organization and clinical decision making in primary care: a qualitative study

BACKGROUND

Primary care professionals often manage patients with multiple long-term health conditions, but managing multimorbidity is challenging given time and resource constraints and interactions between conditions.

OBJECTIVE

To explore GP and nurse perceptions of multimorbidity and the influence on service organization and clinical decision making.

METHODS

A qualitative interview study with primary care professionals in practices in Greater Manchester, U.K. Interviews were conducted with 15 GPs and 10 practice nurses.

RESULTS

Primary care professionals identified tensions between delivering care to meet quality targets and fulfilling the patient's agenda, tensions which are exacerbated in multimorbidity. They were aware of the inconvenience suffered by patients through attendance at multiple clinic appointments when care was structured around individual conditions. They reported difficulties managing patients with multimorbidity in limited consultation time, which led to adoption of an 'additive-sequential' decision-making model which dealt with problems in priority order until consultation resources were exhausted, when further management was deferred. Other challenges included the need for patients to co-ordinate their care, the difficulties of self-management support in multimorbidity and problems of making sense of the relationships between physical and mental health. Doctor and nurse accounts included limited consideration of multimorbidity in terms of the interactions between conditions or synergies between management of different conditions.

CONCLUSIONS

Primary care professionals identify a number of challenges in care for multimorbidity and adopt a particular model of decision making to deliver care for multiple individual conditions. However, they did not describe specific decision making around managing multimorbidity per se.

Are patient beliefs important in determining adherence to treatment and outcome for depression? Development of the beliefs about depression questionnaire

BACKGROUND

Depressive disorders are prevalent and costly but there is a lack of evidence on how to best select treatments for mild to moderate depression in primary care. Illness beliefs have been shown to influence the outcome from physical illness and our previous retrospective study suggested that beliefs may influence the duration of antidepressant medication. The development of a short questionnaire to measure beliefs will allow exploration of the relationship between beliefs, adherence to treatment and outcome for depression.

METHODS

A questionnaire was designed based on Leventhal's Common Sense Model of illness beliefs (CSM). Data from previous qualitative and quantitative studies as well as formal inventories were used to inform the content of individual items. The questionnaire was mailed to primary care patients with a recorded history of depression in the previous 2 years. Data were analysed by principal component analysis to determine underlying multidimensional structure and derive a shortened questionnaire.

RESULTS

Three hundred and thirty-four respondents completed the questionnaire. Fifteen components (subscales) were derived which corresponded to aspects of the CSM dimensions for cause, control/cure, consequences and timeline. The identity dimension was retained as one subscale. Reliability coefficients determined the items which best represented each subscale; 52 items were retained to derive a new shortened questionnaire. Convergent construct validity was demonstrated by comparison with the generic brief illness perception questionnaire (BIPQ) and divergent construct validity was shown by comparison with the Hospital Anxiety and Depression scale (HADs).

LIMITATIONS

The study was adequately powered, but the response rate means that response bias cannot be excluded.

CONCLUSIONS

Beliefs about depression are multi-faceted, but fit the dimensions of the CSM. The derived shortened questionnaire will be used to determine whether beliefs about depression are predictive of outcome in a future prospective study.

Comparative quality of life in patients with depression and rheumatoid arthritis

We assessed the inter-relationships between the Short Form 36 (SF-36) physical and mental function in 220 patients with onset cases of mild and moderate depression and 913 adults with early and established rheumatoid arthritis (RA) through secondary analysis and compared both scores with the UK general population norms. In depression and RA the SF-36 total scores showed significant impairment across the spectrum of both domains compared with age-specific UK normative score. In RA mental health and role, mental scores were highly correlated with other SF-36 domains. In depression there was little evidence of such inter-relationships. Mental health and role mental domains were lowest in active RA (disease activity scores (DAS28) over 5.1). They had strong correlations with the vitality and social function SF-36 sub-scores and weak correlations with the physical function and role emotional sub-scores. Patients with long-term conditions require comprehensive care. At present it is unclear how best to combine treatment of RA synovitis with the management of mental health problems. Mental health symptoms are present from the earliest stages of RA and it may be appropriate to initiate multidisciplinary care as soon as practicable, although its efficacy requires a further detailed study across primary and secondary care.

Spiritual belief, social support, physical functioning and depression among older people in Bulgaria and Romania

OBJECTIVES

An exploratory investigation is reported into the role of spirituality and religious practice in protecting against depression among older people living in rural villages in Bulgaria and Romania, two neighbouring countries with similar cultural, political and religious histories, but with differing levels of current religiosity.

METHODS

In both countries, interviews were conducted with samples of 160 persons of 60 years and over in villages of similar socio-economic status. The Hospital Anxiety and Depression-D scale and the Royal Free Interview for Religious and Spiritual Beliefs were used to assess depression and spiritual belief and practice respectively. In addition social support, physical functioning and the presence of chronic diseases were assessed. One year later, follow-up interviews were conducted with 58 of the original sample in Bulgaria, in which additional measures of depression and of spiritual belief and practice were also included.

RESULTS

The study demonstrates, as expected, significantly lower levels of spiritual belief in the Bulgarian sample (Bulgarian mean 29.7 (SD = 19.1), Romanian mean 47.6 (SD = 11.2), t = 10.2, p < 0.001), as well as significantly higher levels of depression (Bulgarian mean 12.0 (SD = 4.9), Romanian mean 7.3 (SD = 4.1), t = 9.3, p < 0.001), the latter attributable in large part to higher morbidity and disability rates, but less evidently to differences in strength of belief. However, analyses from both the cross-sectional study and the one-year follow-up of the Bulgarian sample do suggest that spiritual belief and practice may both influence and reflect physical and mental illness.

CONCLUSIONS

Much of Eastern Europe displays high rates of depression among its older population and provides opportunities for investigation of the role of religious belief and practice in preventing and coping with depression. Further research is encouraged in populations of diverse religiosity.

Research output on primary care in Australia, Canada, Germany, the Netherlands, the United Kingdom, and the United States: bibliometric analysis

OBJECTIVE

To compare the volume and quality of original research in primary care published by researchers from primary care in the United Kingdom against five countries with well established academic primary care.

DESIGN

Bibliometric analysis.

SETTING

United Kingdom, United States, Australia, Canada, Germany, and the Netherlands. Studies reviewed Research publications relevant to comprehensive primary care and authored by researchers from primary care, recorded in Medline and Embase, with publication dates 2001-7 inclusive.

MAIN OUTCOME MEASURES

Volume of published activity of generalist primary care researchers and the quality of the research output by those publishing the most using citation metrics: numbers of cited papers, proportion of cited papers, and mean citation scores.

RESULTS

82,169 papers published between 2001 and 2007 in the six countries were classified as research on primary care. In a 15% pragmatic random sample of these records, 40% of research on primary care from the United Kingdom and 46% from the Netherlands was authored by researchers employed in a primary care setting or employed in academic departments of primary care. The 141 researchers with the highest volume of publications reporting research findings published between 2001 and 2007 (inclusive) authored or part authored 8.3% of the total sample of papers. For authors with the highest proportion of publications cited at least five times, the best performers came from the United States (n=5), United Kingdom (n=4), and the Netherlands (n=2). In the top 10 of authors with the highest proportions of publications achieving 20 or more citations, six were from the United Kingdom and four from the United States. The mean Hirsch index (measure of a researcher's productivity and impact of the published work) was 14 for the Netherlands, 13 for the United Kingdom, 12 for the United States, 7 for Canada, 4 for Australia, and 3 for Germany.

CONCLUSION

This international comparison of the volume and citation rates of papers by researchers from primary care consistently placed UK researchers among the best performers internationally.

Research output on primary care in Australia, Canada, Germany, the Netherlands, the United Kingdom, and the United States: bibliometric analysis

OBJECTIVE

To compare the volume and quality of original research in primary care published by researchers from primary care in the United Kingdom against five countries with well established academic primary care.

DESIGN

Bibliometric analysis.

SETTING

United Kingdom, United States, Australia, Canada, Germany, and the Netherlands. Studies reviewed Research publications relevant to comprehensive primary care and authored by researchers from primary care, recorded in Medline and Embase, with publication dates 2001-7 inclusive.

MAIN OUTCOME MEASURES

Volume of published activity of generalist primary care researchers and the quality of the research output by those publishing the most using citation metrics: numbers of cited papers, proportion of cited papers, and mean citation scores.

RESULTS

82,169 papers published between 2001 and 2007 in the six countries were classified as research on primary care. In a 15% pragmatic random sample of these records, 40% of research on primary care from the United Kingdom and 46% from the Netherlands was authored by researchers employed in a primary care setting or employed in academic departments of primary care. The 141 researchers with the highest volume of publications reporting research findings published between 2001 and 2007 (inclusive) authored or part authored 8.3% of the total sample of papers. For authors with the highest proportion of publications cited at least five times, the best performers came from the United States (n=5), United Kingdom (n=4), and the Netherlands (n=2). In the top 10 of authors with the highest proportions of publications achieving 20 or more citations, six were from the United Kingdom and four from the United States. The mean Hirsch index (measure of a researcher's productivity and impact of the published work) was 14 for the Netherlands, 13 for the United Kingdom, 12 for the United States, 7 for Canada, 4 for Australia, and 3 for Germany.

CONCLUSION

This international comparison of the volume and citation rates of papers by researchers from primary care consistently placed UK researchers among the best performers internationally.

Estimating probability of sustained recovery from mild to moderate depression in primary care: evidence from the THREAD study

BACKGROUND

It is important for doctors and patients to know what factors help recovery from depression. Our objectives were to predict the probability of sustained recovery for patients presenting with mild to moderate depression in primary care and to devise a means of estimating this probability on an individual basis.

METHOD

Participants in a randomized controlled trial were identified through general practitioners (GPs) around three academic centres in England. Participants were aged >18 years, with Hamilton Depression Rating Scale (HAMD) scores 12-19 inclusive, and at least one physical symptom on the Bradford Somatic Inventory (BSI). Baseline assessments included demographics, treatment preference, life events and difficulties and health and social care use. The outcome was sustained recovery, defined as HAMD score <8 at both 12 and 26 week follow-up. We produced a predictive model of outcome using logistic regression clustered by GP and created a probability tree to demonstrate estimated probability of recovery at the individual level.

RESULTS

Of 220 participants, 74% provided HAMD scores at 12 and 26 weeks. A total of 39 (24%) achieved sustained recovery, associated with being female, married/cohabiting, having a low BSI score and receiving preferred treatment. A linear predictor gives individual probabilities for sustained recovery given specific characteristics and probability trees illustrate the range of probabilities and their uncertainties for some important combinations of factors.

CONCLUSIONS

Sustained recovery from mild to moderate depression in primary care appears more likely for women, people who are married or cohabiting, have few somatic symptoms and receive their preferred treatment.

Guidelines for the management of depression: NICE work?

The National Institute for Health and Clinical Excellence (NICE) recently updated its guidance on managing depression, adding specific guidance for depression in people with physical illness. The guidance should help improve the targeting of treatments, although implementation of the guidance on depression in physical illness is challenging in the National Health Service (NHS) context of separate primary and secondary care services.

Antidepressants, social adversity and outcome of depression in general practice

BACKGROUND

The role of current social risk factors in moderating the impact of antidepressant medication has not previously been explored.

METHOD

In a RCT of SSRIs of general practice patients with mild to moderate depression (HDRS 12-19) two social indices of aversive experience were developed on the basis of prior research. First, the Life Events and Difficulties Schedule (LEDS) was used twice to document: i) recent stressful experience prior to baseline, and ii) after baseline and before follow up at 12 weeks both stressful and positive experiences, taking account of 'fresh start' and 'difficulty-reduction' events. Second, an index of unemployment-entrapment at baseline was developed for the current project. The HDRS was used to measure outcome as a continuous score and as a cut-point representing improvement below score 8.

RESULTS

Each social index (LEDS and Unemployment-entrapment) was associated with a lower chance of remission at 12 weeks and each was required to model remission along with treatment arm. However there was no interaction: the degree of increased remission for those randomised to SSRIs plus supportive care compared to that for those with supportive care alone was the same regardless of social context.

LIMITATIONS

Dating of remission was not as thorough as in previous work with the LEDS. Detailed examination of positive experiences suggested the large majority were not the result of remitting symptoms, but it is impossible to rule this out altogether.

CONCLUSIONS

Remission rates among patients in aversive social contexts are consistently much lower irrespective of treatment. There is thus a need to evaluate the efficacy of alternative more socially focussed interventions for depressive conditions likely to take a chronic course in general practice.

Explaining the rise in antidepressant prescribing: a descriptive study using the general practice research database

OBJECTIVE

To explore the reasons behind the recent increase in antidepressant prescribing in the United Kingdom. Design Detailed retrospective analysis of data on general practitioner consultations and antidepressant prescribing. Data source Data were obtained from the general practice research database, which contains linked anonymised records of over 3 million patients registered in the UK. Data were extracted for all new incident cases of depression between 1993 and 2005. Review methods Detailed analysis of general practitioner consultations and antidepressant prescribing was restricted to 170 practices that were contributing data for the full duration of the study.

RESULTS

In total, 189 851 people within the general practice research database experienced their first episode of depression between 1993 and 2005, of whom 150,825 (79.4%) received a prescription for antidepressants in the first year of diagnosis. This proportion remained stable across all the years examined. The incidence of new cases of depression rose in young women but fell slightly in other groups such that overall incidence increased then declined slightly (men: 7.83 cases per 1000 patient years in 1993 to 5.97 in 2005, women: 15.83 cases per 1000 patient years in 1993 to 10.06 in 2005). Antidepressant prescribing nearly doubled during the study period-the average number of prescriptions issued per patient increased from 2.8 in 1993 to 5.6 in 2004. The majority of antidepressant prescriptions were given as long term treatment or as intermittent treatment to patients with multiple episodes of depression.

CONCLUSIONS

The rise in antidepressant prescribing is mainly explained by small changes in the proportion of patients receiving long term treatment. Previous clinical guidelines have focused on antidepressant initiation and appropriate targeting of antidepressants. To address the costly rise in antidepressant prescribing, future research and guidance needs to concentrate on appropriate long term prescribing for depression and regular review of medication.

Infant sleep disturbance is associated with preconceptional psychological distress: findings from the Southampton Women's Survey

STUDY OBJECTIVE

To determine whether preconceptional psychological distress is associated with infant sleep disturbance.

DESIGN

Prospective cohort study.

SETTING

Southampton, UK.

PARTICIPANTS

A cohort of women from the Southampton Women's Survey (SWS), who were recruited between 20-34 years of age and followed through their subsequent pregnancies and beyond; a total of 874 mother-infant pairs were involved in the study.

MEASUREMENTS AND RESULTS

Preconceptional psychological distress was measured with the General Health Questionnaire (GHQ-12). When their infants were 6 and 12 months of age, mothers were asked to report the number of times babies woke on average between the hours of midnight and 06:00 each night during a 2-week period. Preconceptional psychological distress was a strong predictor of infant night waking at both 6 and 12 months of age, independent of the effects of postnatal depression, bedroom sharing, and other confounding factors. At 6 months, preconceptional distress was associated with a 23% increased risk of waking (prevalence ratio [PR] 1.23, 95% CI 1.06-1.44), and at 12 months with a 22% increased risk (PR 1.22, 95% confidence intervals [CI] 1.02-1.46).

CONCLUSIONS

Women with preconceptional psychological distress are more likely to have babies with sleep disturbance during infancy, independent of whether they suffered from postnatal depression.

Randomised controlled trial to determine the clinical effectiveness and cost-effectiveness of selective serotonin reuptake inhibitors plus supportive care, versus supportive care alone, for mild to moderate depression with somatic symptoms in primary care: the THREAD (THREshold for AntiDepressant response) study

OBJECTIVES

To determine (1) the effectiveness and cost-effectiveness of selective serotonin reuptake inhibitor (SSRI) treatment plus supportive care, versus supportive care alone, for mild to moderate depression in patients with somatic symptoms in primary care; and (2) the impact of the initial severity of depression on effectiveness and relative costs. To investigate the impact of demographic and social variables.

DESIGN

The study was a parallel group, open-label, pragmatic randomised controlled trial.

SETTING

The study took place in a UK primary care setting. Patients were referred by 177 GPs from 115 practices around three academic centres.

PARTICIPANTS

Patients diagnosed with new episodes of depression and potentially in need of treatment. In total, 602 patients were referred to the study team, of whom 220 were randomised.

INTERVENTIONS

GPs were asked to provide supportive care to all participants in follow-up consultations 2, 4, 8 and 12 weeks after the baseline assessment, to prescribe an SSRI of their choice to patients in the SSRI plus supportive care arm and to continue treatment for at least 4 months after recovery. They could switch antidepressants during treatment if necessary. They were asked to refrain from prescribing an antidepressant to those in the supportive care alone arm during the first 12 weeks but could prescribe to these patients if treatment became necessary.

MAIN OUTCOME MEASURES

The primary outcome measure was Hamilton Depression Rating Scale (HDRS) score at 12-week follow-up. Secondary outcome measures were scores on HDRS at 26-week follow-up, Beck Depression Inventory, Medical Outcomes Study Short Form-36 (SF-36), Medical Interview Satisfaction Scale (MISS), modified Client Service Receipt Inventory and medical record data.

RESULTS

SSRIs were received by 87% of patients in the SSRI plus supportive care arm and 20% in the supportive care alone arm. Longitudinal analyses demonstrated statistically significant differences in favour of the SSRI plus supportive care arm in terms of lower HDRS scores and higher scores on the SF-36 and MISS. Significant mean differences in HDRS score adjusted for baseline were found at both follow-up points when analysed separately but were relatively small. The numbers needed to treat for remission (to HDRS > 8) were 6 [95% confidence interval (CI) 4 to 26)] at 12 weeks and 6 (95% CI 3 to 31) at 26 weeks, and for significant improvement (HDRS reduction > or = 50%) were 7 (95% CI 4 to 83) and 5 (95% CI 3 to 13) respectively. Incremental cost-effectiveness ratios and cost-effectiveness planes suggested that adding an SSRI to supportive care was probably cost-effective. The cost-effectiveness acceptability curve for utility suggested that adding an SSRI to supportive care was cost-effective at the values of 20,000 pounds-30,000 pounds per quality-adjusted life-year. A poorer outcome on the HDRS was significantly related to greater severity at baseline, a higher physical symptom score and being unemployed.

CONCLUSIONS

Treatment with an SSRI plus supportive care is more effective than supportive care alone for patients with mild to moderate depression, at least for those with symptoms persisting for 8 weeks and an HRDS score of > or = 12. The additional benefit is relatively small, and may be at least in part a placebo effect, but is probably cost-effective at the level used by the National Institute for Health and Clinical Excellence to make judgements about recommending treatments within the National Health Service. However, further research is required.

How could depression guidelines be made more relevant and applicable to primary care? A quantitative and qualitative review of national guidelines

BACKGROUND

Many guidelines have been developed in the area of depression but there has been no systematic assessment of their relevance to general practice.

AIM

To assess national guidelines on general practice management of depression using two complementary approaches to identify specific ways in which guidance could be made more relevant and applicable to the nature of general practice and the patients who seek help in this context.

DESIGN OF STUDY

Review of national guidelines.

SETTING

Seven English speaking countries: UK, US, Australia, New Zealand, Ireland, Canada, and Singapore.

METHOD

Seven guidelines were independently reviewed quantitatively using the Appraisal of Guidelines for Research and Evaluation (AGREE) scores and qualitatively using thematic coding.

RESULTS

The quantitative assessment highlights that most of the guidelines fail to meet the criteria on rigour of development, applicability, and editorial independence. The qualitative assessment shows that the majority of guidelines do not address associated risk factors sufficiently and the dilemma of diagnostic uncertainty flows over into management recommendations. Management strategies for depression (antidepressants and psychological strategies) are supported by all of the guidelines, with several listing drugs before psychological therapies; there is limited attention paid to the different types of psychological therapies. Moreover, the guidelines in the main fail to acknowledge individual patient circumstances, in particular the influence on response to treatment of social issues such as adverse life events or social support.

CONCLUSION

Assessments of current national guidelines on depression management in general practice suggest significant limitations in their relevance to general practice.

Patients' and doctors' views on depression severity questionnaires incentivised in UK quality and outcomes framework: qualitative study

OBJECTIVE

To gain understanding of general practitioners' and patients' opinions of the routine introduction of standardised measures of severity of depression through the UK general practice quality and outcomes framework.

DESIGN

Semistructured qualitative interview study, with purposive sampling and constant comparative analysis.

PARTICIPANTS

34 general practitioners and 24 patients.

SETTING

38 general practices in three sites in England: Southampton, Liverpool, and Norfolk.

RESULTS

Patients generally favoured the measures of severity for depression, whereas general practitioners were generally cautious about the validity and utility of such measures and sceptical about the motives behind their introduction. Both general practitioners and patients considered that assessments of severity should be seen as one aspect of holistic care. General practitioners considered their practical wisdom and clinical judgment ("phronesis") to be more important than objective assessments and were concerned that the assessments reduced the human element of the consultation. Patients were more positive about the questionnaires, seeing them as an efficient and structured supplement to medical judgment and as evidence that general practitioners were taking their problems seriously through a full assessment. General practitioners and patients were aware of the potential for manipulation of indicators: for economic reasons for doctors and for patients to avoid stigma or achieve desired outcomes.

CONCLUSIONS

Despite general practitioners' caution about measures of severity for depression, these may benefit primary care consultations by increasing patients' confidence that general practitioners are correct in their diagnosis and are making systematic efforts to assess and manage their mental health problems. Further education of primary care staff may optimise the use and interpretation of depression questionnaires.

Management of depression in UK general practice in relation to scores on depression severity questionnaires: analysis of medical record data

OBJECTIVE

To determine if general practitioner rates of antidepressant drug prescribing and referrals to specialist services for depression vary in line with patients' scores on depression severity questionnaires.

DESIGN

Analysis of anonymised medical record data.

SETTING

38 general practices in three sites-Southampton, Liverpool, and Norfolk. Data reviewed Records for 2294 patients assessed with severity questionnaires for depression between April 2006 and March 2007 inclusive.

MAIN OUTCOME MEASURES

Rates of prescribing of antidepressants and referrals to specialist mental health or social services.

RESULTS

1658 patients were assessed with the 9 item patient health questionnaire (PHQ-9), 584 with the depression subscale of the hospital anxiety and depression scale (HADS), and 52 with the Beck depression inventory, 2nd edition (BDI-II). Overall, 79.1% of patients assessed with either PHQ-9 or HADS received a prescription for an antidepressant, and 22.8% were referred to specialist services. Prescriptions and referrals were significantly associated with higher severity scores. However, overall rates of treatment and referral were similar for patients assessed with either measure despite the fact that, with PHQ-9, 83.5% of patients were classified as moderately to severely depressed and in need of treatment, whereas only 55.6% of patients were so classified with HADS. Rates of treatment were lower for older patients and for patients with comorbid physical illness (including coronary heart disease and diabetes) despite the fact that screening for depression among such patients is encouraged in the quality and outcomes framework. Conclusions General practitioners do not decide on drug treatment or referral for depression on the basis of questionnaire scores alone, but also take account of other factors such as age and physical illness. The two most widely used severity questionnaires perform inconsistently in practice, suggesting that changing the recommended threshold scores for intervention might make the measures more valid, more consistent with practitioners' clinical judgment, and more acceptable to practitioners as a way of classifying patients.

A longitudinal study of blood folate levels and depressive symptoms among young women in the Southampton Women's Survey

BACKGROUND

Lower blood folate levels have been associated with depression in cross-sectional surveys, but no studies have examined the relationship prospectively to determine whether the relationship is causal. A follow-up study was designed to examine whether lower blood folate levels predict incident depressive symptoms.

METHOD

Women aged 20-34 years registered in general practices in Southampton, UK, were asked to participate. Baseline assessment included the general health questionnaire (GHQ-12) measure of anxiety and depression, and socioeconomic factors, diet, smoking and alcohol intake. Two years later, participants' general practice (GP) records were examined for evidence of incident symptoms of depression.

RESULTS

At baseline, 5051 women completed the GHQ-12 and had red cell folate levels measured, of whom 1588 (31.4%) scored above the threshold for case level symptoms of anxiety and depression on the GHQ-12. Two years later, GP records for 3996 (79.1%) were examined, but 1264 with baseline evidence of depression were excluded from follow-up analysis. Incident depressive symptoms were recorded for 307 (11.2%) of the remaining 2732. Lower red cell folate levels were associated with caseness on the GHQ-12 (adjusted prevalence ratio 0.99 per 100 nmol/l red cell folate, 95% CI 0.98 to 1.00). No relationship was found between red cell folate levels and incident depressive symptoms over 2 years (adjusted hazard ratio 1.00, 95% CI 0.97 to 1.03).

CONCLUSIONS

Low folate levels were not associated with subsequent depressive symptoms. This suggests that lower blood folate levels may be a consequence rather than a cause of depressive symptoms.