Depression and long-term conditions
Depression is the largest cause of disease burden of all mental health problems and is estimated to become the highest among all health problems by 2030.1 It accounts for 4.3% of the global disease burden and causes 63 million disability-adjusted life-years each year.1 Approximately 30% of the UK population have a long-term health condition (LTC) (e.g. diabetes mellitus or asthma), and in those who do there is a two- to threefold increase in the prevalence of depression.2 This combination of depression and LTCs can result in poorer health outcomes, lower quality of life and a reduced ability to self-manage, and contributes substantially to health inequalities.2–4 Furthermore, people with depression are more likely to have two or more LTCs and this group experience the greatest decrements in quality of life.5
The importance of comorbid depression and LTCs (mental–physical multimorbidity) is well established from the epidemiological and economic perspectives. The cost of care for people with mental–physical multimorbidity is 45% higher than for those without.2 The NHS Five Year Forward View6 recognises that 30% of the population live with a LTC, the treatment of which accounts for 70% of total NHS costs; the most common and disabling multimorbidity is physical health alongside common mental disorders.7 There is a need for an integrated patient-centred approach to support the mental–physical care of this underserved population.7 The NHS Long Term Plan8 emphasises the need to provide better care for people with LTCs with expanded neighbourhood teams comprising a range of staff, such as general practitioners (GPs), pharmacists, district nurses, community geriatricians, dementia workers and allied health professionals (e.g. physiotherapists and podiatrists/chiropodists), joined by social care and the voluntary sector.8
Subthreshold depression
Subthreshold depression is highly prevalent and is a major risk factor for progression to major depression.9 It is defined as between two and four symptoms of depression, at least one of which must be either low mood or loss of interest or pleasure.10 With comparable rates of excess mortality to those of major depression,11 estimates suggest that the prevalence of subthreshold depression in community samples ranges from 1.4% to 17.9%.12 Prevalence estimates increase to up to 20% in those with LTCs; for this population, clinical guidelines recommend brief psychological support.13 Although psychological interventions can reduce symptoms of depression in those with subthreshold depression (thus reducing the incidence of major depression), over 80% of people with ‘below-threshold’ mental health conditions remain untreated in psychological health-care services because they are often unable to meet the demand for treatment of major depression.14 However, when people with frailty or physical health problems are referred to mental health services, they often do not make use of such services because of access issues and they often find the psychological approaches on offer unacceptable.15 There is perhaps a need to move beyond traditional reliance on health services delivery; a public health approach to subthreshold depression in at-risk groups, such as those with LTCs, may offer alternative opportunities to provide health-care interventions in innovative and accessible settings.
Community pharmacies
In England, community pharmacies (CPs) are the most accessible and available health-care provider in the community, with 89% of the population able to access a CP from home within a 20-minute walk.16 Importantly, in areas of the highest deprivation, this figure increases to almost 100%, an observation termed the positive pharmacy care law.17,18 In terms of delivering health-care services to the people who need the services the most, CPs are uniquely placed in our local communities to achieve this. At present, there are approximately 11,600 CPs in England. Many of these are open in evenings and at weekends, which allows a range of different people, including those who work during the day, access to health care and public health services.16 They offer people the opportunity to consult with a community pharmacist without a prior appointment, at a convenient time and in an accessible location. Published qualitative research also suggests that people often form trusting relationships with their local community pharmacist, which means that they are more likely to consult with them and ask for health advice than they are to consult with some other health-care professionals.19 Further work has also shown that people with mental health conditions value CP services, particularly those reflecting patient-centred care, and are happy to engage with such services.20 Examining experiences of CP users more broadly showed that people do not expect to routinely receive public health services in this setting, but that when they do they are highly satisfied with such services; however, there were mixed views on the ability of the pharmacist to do this effectively.21
Community pharmacies, therefore, have the potential to deliver services that are aimed at promoting health and preventing disease. Recent examples of these services have focused on health promotion, including smoking cessation and weight management services.22 These opportunities are also supported by recent policy drivers that allow CPs to deliver more patient-focused services, as outlined in the recently published Summary of the Five-Year Deal on the Community Pharmacy Contractual Framework.23 The potential of the CP network has also been acknowledged by policy-makers as a way of helping the NHS to deliver on its long-term strategic plan.24
An example at the national level of the changing role of the CP is the Healthy Living Pharmacy (HLP) programme. This is a tiered and structured commissioning framework that aims to deliver high-quality, patient-focused services from CPs to improve the health and well-being of the local population.25 Crucially, the framework has provision to involve the wider pharmacy team who are able to train as Healthy Living Champions (HLCs): a formal qualification in understanding health improvement, accredited by the Royal Society of Public Health. Since April 2020, all CPs in England have been required to obtain HLP status as part of the agreement between the Pharmaceutical Services Negotiating Committee, NHS England and NHS Improvement, and the Department of Health and Social Care.
These developments support and complement the existing patient-focused services available through CPs, such as the flu vaccination and smoking cessation. A recent review of reviews26 examined the effectiveness of CP-delivered public health services and concluded that there are a number of CP services that have positive intervention effects on health outcomes. These services are predominantly focused on primary disease prevention and include smoking cessation, weight management programmes, syringe exchange programmes and inoculation services. The review also concluded that, although there is evidence of CP-delivered services being able to target people with physical health conditions, there is a dearth of literature exploring if (and how) CPs could deliver public mental health services and, given the reach of CPs in deprived areas, how these services could impact on health inequalities.
Developments such as the HLP programme lend support to the NHS and Public Health England’s Five Year Forward View6 plan, which calls for a radical upgrade in public health, including new partnerships that ‘break down barriers’ to support people with multiple health problems. In support of this, and owing to the socioeconomic disparities and the impact of physical–mental comorbidities, the Marmot27 report on health inequalities recommended a focus on the mental health of people with LTCs. There are many similarities between the behaviour change/management approaches to subthreshold depression (i.e. goal-setting, facilitated self-help and diary-keeping) and the public health interventions already being delivered by HLCs in CPs. CPs may, therefore, be well placed to offer and deliver opportunistic enhanced support to people with a range of health problems, such as comorbid subthreshold depression and LTCs, alongside the health promotion services and behaviour change programmes that they already provide.28
Evidence for enhanced support interventions
A number of non-pharmacological treatments are recommended by the National Institute for Health and Care Excellence (NICE) for depression in people with LTCs.12,13 A recent Cochrane review29 highlighted collaborative care as having particular relevance to people with multimorbidity. Collaborative care ensures delivery of effective forms of treatment30 and uses session-by-session symptom profiling, medication management, patient education and brief evidence-based psychological interventions to optimise outcomes.31,32 The evidence supporting collaborative care for people with depression33,34 is strong, especially when it includes a structured psychological intervention.35 Collaborative care for depression is also effective when delivered by non-mental health specialists and for comorbid LTCs.36
This collaborative care framework has been adapted to include a low-intensity psychosocial intervention for subthreshold depression.37,38 The Collaborative Care for Screen Positive Elders (CASPER) trial38 developed an effective intervention for people with subthreshold depression (90% of whom also had comorbid LTCs) within primary care. This collaborative care intervention involved facilitated self-help and was based on behavioural activation (BA) supported by non-mental health specialists. This study reported a significant reduction in depression symptoms at 4 and 12 months (with an effect size of 0.30) for those people in the intervention group compared with those in the usual-care group. Importantly, significantly fewer people in the intervention group than in the usual-care group progressed to major depression at 12 months.38 This finding supports existing depression prevention literature30 and lends support to the use of similar non-mental health specialist-supported interventions to target at-risk populations.39,40 Further research is now needed to establish the suitability and effectiveness of such a prevention intervention as a public health initiative.
Rationale for CHEMIST
The Community Pharmacies Mood Intervention Study (CHEMIST) aimed to evaluate the potential for delivery of a behavioural change depression prevention intervention (similar to that implemented in the CASPER trial) within the important public health setting of CPs. Reviews of the literature at the time of the design of CHEMIST indicated that the existing evidence was not sufficiently robust, or experience in this area of research sufficiently developed, to support a definitive randomised controlled trial (RCT) at this stage in the evolution of this public health intervention. CHEMIST, therefore, sought to adapt ‘what works’ for people with subthreshold depression in primary care38,41 and evaluate this for use within a CP public mental health setting for people experiencing comorbid subthreshold depression and LTCs.
To the best of our knowledge, CHEMIST is the first to test the feasibility of an intervention (and associated study procedures) developed to utilise the unique opportunity of CPs to offer depression prevention alongside their other health promotion activities. CHEMIST aimed to provide high-quality evidence to inform the design and delivery of such a service and deliver the important preparatory work ahead of a definitive RCT that is needed to evaluate the clinical effectiveness and cost-effectiveness of such an intervention. CHEMIST adds to the existing limited evidence base on the use of CPs for the management of people’s mental health-care needs.42,43
Research objectives
Feasibility study
- To refine the bespoke enhanced support intervention (ESI) (including patient self-help materials, ESI manual and training) for implementation by CP staff to people with subthreshold depression and LTCs based on evidence-supported interventions in primary care.
- To develop and refine study procedures (CP set-up and recruitment strategies; participant screening, recruitment and assessment; suitability of outcome measures; and data collection procedures) for testing in the external pilot RCT.42
External pilot randomised controlled trial
- To quantify the flow of participants (eligibility, recruitment and follow-up rates).
- To evaluate proposed recruitment, assessment and outcome measure collection.
- To examine the delivery of the ESI in a CP setting (ESI uptake, retention and dose) to inform the process evaluation.
- To conduct a process evaluation, using semistructured interviews with participants, pharmacy staff and GPs across a range of socioeconomic settings, to explore the acceptability of the ESI within the CP setting, elements of the ESI that were considered useful (or not), and the appropriateness of study procedures.42
Progression criteria
Progression criteria would inform the decision of the Trial Steering Committee (TSC) and the funder in the continuation of the study from the feasibility study to the external pilot RCT, and in the feasibility of conducting a definitive RCT (to test the clinical effectiveness and cost-effectiveness of the ESI for people with subthreshold depression and LTCs within a CP setting).
Feasibility study to external pilot randomised controlled trial
- Recruit five participants at each of four to six CPs by month 6.
- For 80% of participants to receive two or more ESI sessions within the 4-month post-recruitment period.
- Collect valid (intended) primary outcome measure on 80% of recruited participants at the 4-month post-recruitment follow-up.
- A fidelity score of ‘acceptable’ (3) or above to be achieved in at least 90% of assessed audio-recorded ESI sessions.
External pilot randomised controlled trial to a definitive randomised controlled trial
- Recruit and randomise 100 participants across five or six CPs by month 20.
- For 80% of participants randomised to the ESI to receive two or more ESI sessions within the 4-month post-randomisation period.
- Collect valid (intended) primary outcome measure on 80% of participants at the 4-month post-randomisation follow-up.