Mental health social work in multidisciplinary community teams: An analysis of a national service user survey

Summary The article addresses the continued lack of clarity about the role of the mental health social worker within community mental health teams for working age adults and particularly the limited evidence regarding this from the perspective of service users. It compares findings from the literature, found to originate from a predominantly professional viewpoint, with secondary analysis of a national survey of service users to assess their views. Findings Three particular aspects of mental health social workers’ role identified in the literature were, to some extent, also located within the national survey and can be summarised as: approaches to practice, nature of involvement, and scope of support. The presence of these features was largely not substantiated by the survey results, with few differences evident between service users’ experiences of mental health social workers compared with other mental health staff. When nurses and social workers were compared, results were either the same for both professions or favoured nurses. The findings point both to the difficulty of articulating the social work contribution and to the limitations of the secondary data. Application The findings are a useful benchmark, highlighting the limited evidence base and the need for further research to improve both the understanding of the mental health social work role and how it is experienced by service users. The profession is keen to emphasise its specific contribution. Research evidence is required to underscore this and to ensure that the role is not subsumed within generic practice.


Introduction
Social workers have played a major role in the development of community mental health services for adults in England. Deinstitutionalisation policies from the mid-20th century demanded enhanced community support services (Department of Health (DH), 1962;Mental Health Act, 1959), which in turn drew on key social work values linking successful support with the need for understanding of the dynamics between patients, their families, communities and wider social forces. Additionally, social work's long history of individual casework orientated to people in their own homes and communities naturally lent itself to the needs of new services. More specifically, the 1959 Mental Health Act gave additional responsibilities to social workers including post hospital discharge support (Burns, 2014). A decade later, the Medical-Psychological Association (1969) recommended that a new body of mental health social workers with additional training was now required to support the growing numbers of people with profound and complex mental health needs living in the community (Godin, 1996). The introduction of the Approved Social Worker in 1983 (Mental Health Act, 1983) conferred on this group of staff further duties and responsibilities to conduct assessments where formal detention was considered. Within this role their duty included investigating the feasibility of community alternatives to avoid hospital admission (Rapaport, 2005). These factors reinforced the shift away from genericism in the social work role (Challis & Ferlie, 1987, 1988. Furthermore, government policies which sought to reorient mental health services towards care in the community often included an enhanced role for social workers within integrated services (e.g. DH, 1975DH, , 1989DH, , 1990DH, , 1995DH, , 1998Health Act, 1999).
New approaches to support involved multidisciplinary services and focused on early intervention and the maintenance of independence (Anthony, 1993;Hibbard & Gilburt, 2014). Today such services are the norm, with social work joining psychiatry, nursing, psychology and occupational therapy in a spectrum of specialist community teams (Malone, Marriott, Newton-Howes, Simmonds, & Tyrer, 2007). Such teams are increasingly prevalent across Europe, North America and Australasia (Draper & Anderson, 2010;Evans et al., 2012;Ng, Herrman, & Chiu, 2009). These multidisciplinary teams encompass the early assessment and diagnosis of psychiatric conditions and the coordination of long-term support and care to meet specific needs.
However, as social workers have been included within the wider mental health system, boundaries between professionals have blurred with a 'creeping genericism' gradually eroding traditional roles (Brown, Crawford, & Darongkamas, 2000, p. 426). Role blurring and the erosion of traditional professional practices have become a salient issue for many practitioners (Jones, 2014). This is evidenced, for example, by clinical psychologists helping to organise accommodation for service users, and social workers implementing psychotherapeutic interventions (Abendstern et al., 2014;Brown et al., 2000;Wall, 1998). The increasing pressure on social workers and other members of community mental health teams (CMHTs) for adults to move towards more generic roles has furthered a lack of clarity regarding what social workers should do compared to other professionals, whilst roles that were specific to them historically, such as the approved social work role, have been opened up to others (Bailey & Liyanage, 2012). Social work has long been recognised as difficult to define (Allen, 2014;Howe, 1979;Rode, 2017) and more recently role blurring has added to the challenge of articulating its unique contribution to mental health.
This poses distinct challenges for the practice and organisation of mental health social work. First, service users may be unclear about the roles and remit of social work in their mental health care, which may undermine confidence and impede the contribution that social workers can then make (ComRes, 2017). Second, repeated studies have found that mental health social work staff in multidisciplinary environments have relatively poor job satisfaction and face significant risk of stress Huxley et al., 2005;Onyett, 2011). This is empirically linked to social worker perceptions that their core skills and knowledge are not well matched with those demanded in their role (Wilberforce et al., 2013). Third, there appears to be a growing trend towards the removal of mental health social workers from multidisciplinary environments, at least based on anecdotal reports (ADASS, 2018;Lilo, 2016;McNicoll, 2016), for fear that social workers are not being utilised appropriately. Such decisions are (inevitably) being taken without appropriate evidence asserting their unique role.
This article aims to articulate the unique contribution of the social work role in mental health through a synthesis of two processes. First, a focussed review of the literature was undertaken to identify the features of the social worker role in mental health care. Second, a new analysis of nationally collected data from the Care Quality Commission (CQC) was employed to identify service user perspectives of social work in mental health. These data enabled a comparison to be made between the experiences of service users supported by social workers and those supported by other professionals.

Review of literature
This review sought to identify and synthesise the literature on the distinct contribution of the social work role in mental health. It was designed to serve the needs of a wider research study investigating the contribution of social work in CMHTs (underway at the time of writing, and which required the collation of a list of attributes to incorporate into data collection tools). 'Contribution' was defined by the research team as including both 'what' they do and 'how' they do it, acknowledging that social workers may do similar tasks to other professions, but in a different way. The pragmatic aims meant there was no requirement for the review to be exhaustive. Nevertheless, good practice in literature reviewing was followed drawing upon rapid review methods as a means of expediting the identification and synthesis of existing literature. Whilst no formal definition for a rapid review exists, the process adopted used Tricco et al.'s (2015) working definition which states that they are 'a type of knowledge synthesis in which components of the systematic review process are simplified or omitted to produce information in a short period of time ' (p. 225). In line with this, they tend to be characterised by a restriction of searches to one or two databases, limiting search terms, and a presentation of results within a narrative summary with no quality appraisal.
Three different sources of literature were reviewed. The first identified six authoritative textbooks which described mental health practice and generic social work (Briar & Miller, 1971;Davies, 2012;Goldstein, 1973;Golightley & Geomans, 2014;Moxley, 1989;Raiff & Shore, 1993). These texts were selected by two of the authors (DC, JH), with professional social work qualifications and the most extensive experience from within the research team, making a pragmatic choice from existing textbooks known to them. The second consisted of existing research and practice documents known to the authors to be closely aligned to the intent of the present review, that is the nature of social work practice today (e.g. All Party Parliamentary Group, 2016; Moriarty et al., 2015;Moriarty & Manthorpe, 2016). Finally, a bespoke literature search of two databases was undertaken (Web of Science and PsychInfo) using the search terms 'social work*' AND (role OR function) AND 'community mental health', restricted to the period 1999-2017. Broad inclusion criteria enabled the capture of evidence of social work attributes within both generic and specialist mental health social work. All included texts were required to include descriptions of one or more social work attribute, in line with the aim of the review which sought to collate a list of such features. This yielded 85 references after duplicates were removed. Titles and abstracts were reviewed by all the research team and any abstract identified as relevant by any member (n ¼ 44) were obtained, bar five items that could not be sourced. Those with exclusive focus on older adults services were also excluded (n ¼ 2).
For each included source, a short summary narrative of social workers' contributions was produced and entered into MS Excel (RP). These were then discussed by the wider authorship group who, through an iterative process, identified three broad areas under which the findings were collated: 'approaches to practice', 'nature of involvement' and 'scope of support'. Within these headings, RP and MW jointly devised sub-themes by reviewing all Excel entries, revising and updating these as the analysis progressed. The final step involved providing a narrative commentary of each theme and sub-theme, with an example of social work practice illustrating each in practice. The aim was to draw out distinctions where possible. Decisions were pragmatic rather than definitive with overlap acknowledged, indicative of the characteristics of social work practice.

Secondary data: Community Mental Health Service User Survey 2016
The CQC (2016) annual Community Mental Health Survey data were selected for analysis, as a standardised survey with national coverage. Its primary aim is to find out what service users think about the NHS health care services they use, to highlight good care and to identify the potential risks to the quality of services. The survey consists of 47 questions with 41 of these asking about the service users' specific experience of the care they receive. Twelve of these questions were analysed, being those most relevant to the core aim of the article: to articulate the social work role within these services (see Tables 2 to 4 for details). These were organised according to the literature review themes: approaches to practice (n ¼ 3), nature of involvement (n ¼ 7) and scope of support (n ¼ 2). The responses are collected using Likert-type categories. The survey also asks who is the main person organising the service users' care, providing an opportunity for comparison between social workers and community mental health nurses (CMHNs) as care coordinators.
Settings. All trusts providing community mental health services in England were eligible to take part in the survey. Fifty-eight providers of NHS mental health services in England, including combined mental health and social care trusts, foundation trusts and community health care social enterprises commissioned by trusts, provided mental health services. Fieldwork for the survey took place between February and June 2016.
Respondents. Each NHS trust providing or commissioning mental health services drew a random sample from their records of 850 people receiving services. Service users were eligible to complete the Community Mental Health User Survey if they were over 18 years of age and had received specialist care or treatment for a mental health condition from a community-based treatment or care service, delivered through a mental health trust during the sampling period. This also included those who received care under the Care Programme Approach. Several exclusions were applied by the authors, including specialist services for people with learning disabilities, drug and alcohol problems, and forensic psychiatry. Further, those only seen for assessment, those who were inpatients at the time of the survey and people seen exclusively by Improving Access to Psychological Therapies services were excluded. Full details are provided in CQC (2016).
The CQC dataset comprised 12,522 people who had seen a mental health practitioner in the previous 12 months, 2739 of whom were care coordinated by a CMHN and 802 by a social worker. Some respondents perceived that more than one professional acted as care coordinator and were removed from the analysis. The final sample comprised 2575 and 682 people whose care was coordinated by a CMHN and social worker, respectively.
Analysis. Data analysis on the selected CQC questions, which were grouped into three themes, was conducted using SPSS statistical software. Effect sizes were also calculated, however, only as a guide since the data were categorical not continuous. This permitted quantification of the difference between two groups and is helpful in large samples where small differences may be statistically significant. The effect size is the standardised mean difference between the two groups. By convention, an effect size of 0.2 or less is 'small' (Cohen, 1977).

Results
Following a description of the characteristics of the literature and survey sample, the results are described under three sub-headings, each of which contains findings from the literature followed by the results of the secondary data analysis of the related survey questions. A final section about overall satisfaction contains survey data only.

Literature characteristics
Together the three sources produced 59 articles and books published between 1971 and 2016. The majority (n ¼ 32) came from the UK with a substantial number (n ¼ 17) being published in the US. A smaller amount came from a range of European countries (n ¼ 10). The descriptions of social worker contributions were organised under the three interlinked themes already noted. The CQC data were then also arranged under those headings. Each theme contained a number of sub-themes which are outlined below. The included literature was dominated by non-empirical texts in the form of published books and articles (n ¼ 28) and grey literature (n ¼ 11). Twenty empirical research articles were included of which 13 reported data collected from social workers. Only three reported the perspectives of service users. Unless otherwise stated, the data reflect a mix of empirical research and opinion from social work experts within academia and/or policy environments.

Survey sample characteristics
Service user characteristics are displayed in Table 1. There were no significant differences between the two groups (those supported by a social worker and those supported by a CMHN) with regard to gender, age or time spent in services. However, on average service users on CMHN caseloads had been seen more recently compared to service users on social worker's caseloads. Also significantly

Approaches to practice
The literature. Three areas were identified within the literature on this theme: that social work theory and practice is situated within an understanding of society as socially biased against the vulnerable, starts from a holistic perspective and prioritises good working relationships with individuals to support positive change. Social work practice in mental health and other services was reported to be intentionally non-neutral, framed by an assumption that people with mental health problems are vulnerable to abuses of their human rights (Ife, 2012) and face greater difficulties in accessing health and welfare services, education and training, employment, housing and participation in civic society (Ahmedani, 2011). Further, discrimination due to mental health was recognised in social work texts as inseparable from other forms of injustice, for example with regards to ethnicity and culture or sexual and gender identities (Allen, 2014;Faust, 2008;Golightley & Geomans, 2014;Ramon, 2010).
Social workers were also said to be guided by an awareness and understanding of how individual wellbeing is inextricably linked to their social environment (Goldstein, 1973;Raiff & Shore, 1993). As a consequence social work has been identified as being cautious about the medical model of psychiatry, as insufficient to explain causes and consequences of mental health problems (Carpenter, Schneider, Brandon, & Wooff, 2003), described as impeding mental health recovery due to an overriding focus on deficits alone (Davies, 2012;Ramon, 2010;Stanley, 2003;Stromwall & Hurdle, 2003). A holistic approach that takes into account a person's wider needs and social context was said to be valued by service users (Beresford, 2007).
More generally, the social worker's approach was described as prioritising a positive working relationship with clients and their families built on compassion (Ramon, 2010), trust and clear, uncomplicated, communication (Allen, 2014;Golightley & Geomans, 2014;Hardiker & Barker, 1999;Herman, 2014;Peck & Norman, 1999). Mental health social work training has long included relationship work as one component of their duties (Perlman, 1979). More recently, this has received attention as part of recovery principles, allied with concepts of 'hope', 'strengths' and 'control' to improve social functioning and promote engagement in the wider community (Allen, 2014;Pahwa, Smith, McCullagh, Hoe, & Brekke, 2016). An emphasis on self-awareness including limited self-disclosure (Golightley & Geomans, 2014) and the ability to actively listen and empathise with service users (Faust, 2008;Penhale & Young, 2015) were also skills acknowledged to be required to build positive working relationships. Two publications which focussed on users' views stressed that the social worker's approach to practice, including kindness, sensitivity, reliability and a non-judgemental attitude, was paramount to service users' satisfaction with social work (Beresford, 2007;Penhale & Young, 2015).
The secondary data. The three questions within this theme spanned careful listening, whether service users were given enough time, and how well they thought they were understood by their key worker. Descriptive statistics for these questions are displayed in Table 2. There were significant differences for all three questions, with respondents in the CMHN group answering more positively compared to those in the social worker group, although the effect sizes were small (all d0.13).

Nature of involvement
The literature. This theme includes the sub-themes of advocacy, anti-oppressive practice and the exercise of care coordination. Advocacy has been described as a routine element of social work ensuring that service users' rights are upheld and respected (Cummings & Cassie, 2015;Davis & Jung, 2012;Manktelow et al., 2002). Social workers were characterised in the literature as promoting social justice, giving the powerless a voice (Faust, 2008) and supporting people to express themselves so that they could be 'recognised on equal terms with others' (Parrott, 2014, p. 105). Anti-oppressive practice in social work, linked to challenging discrimination along all lines of difference (Beresford, 2007) has emerged from social work training that articulated theories and practices related to resolving differential power relationships within families, social networks, public services and communities.  (7) CMHN: community mental health nurse.
One of the key vehicles through which social workers engage service users and their social networks in promoting self-determination is through their involvement in care coordination, which in social work is also geared towards changing the power balance between the supported and those supporting them (Herman, 2014;Penhale & Young, 2015;Ring, 2001). In terms of assessment activity, social workers were found to make key links between psychiatric, psychological and social functioning together with reviewing risk and physical health needs (Aschbrenner et al., 2015;DH, 1999). In relation to care planning and coordination, social workers play a key role in creating comprehensive and personalised care plans which reflect an individual's needs, preferences and strengths and enable individuals to live more independently (Allen, 2014;Raiff & Shore, 1993). This role is reported to involve arranging, purchasing and monitoring social care packages and referrals (Marshall, Lockwood, & Gath, 1995;Moxley, 1989) and therefore involves liaising, mediating and negotiating with other professionals and agencies to ensure continuation of care (Cummings & Cassie, 2015;Janl€ ov, Gransk€ ar, & Berg, 2015). Social workers were also reported to liaise closely with nurses, care agencies and voluntary organisations, GPs and hospitals, and specialist psychological support services (Golightley & Geomans, 2014) to coordinate care and ensure service users' and carers' needs are appropriately met (Hardiker & Barker, 1999). Mulhall (2000) found that service users wanted to be treated with respect, to be involved in planning their own care and to be listened to, all of which have been identified as core skills of social workers. Additionally, Beresford (2007) reported that service users valued social workers for their focus on supporting independence and participation rather than dependence.
The secondary data. Seven questions were linked to the theme of coproduction covering the level of involvement of the service user and their wider network in planning and reviewing their care. The questions focused on the extent of involvement in discussions about care needs, formulating plans and agreeing decisions. Descriptive statistics are displayed in Table 3.
Significant differences emerged in relation to the level of involvement in agreeing the care the service user would receive, with service users on the CMHN caseload seeming more satisfied, although effect sizes were small (ds 0.12). No other significant differences were found within this theme, suggesting that both CMHNs and social workers involved the service users and their wider networks in decisions surrounding their care to the same extent.
The scope of social work support The literature. The literature described three elements of support provided by social workers: knowledge of and ability to access a broad range of resources, direct interventions, and statutory roles requiring specific knowledge and skills. A central contribution of social work to mental health care, as noted above, is its wide frame of reference compared to a more medicalised model: if a person is to be viewed holistically, then the range of support must not be constrained to clinical resources. Social workers were found to be knowledgeable about services available through the local authority, including social care and housing (Mitchell & Patience, 2002). King et al.'s (2002) survey comparing different professionals in community mental health services found social workers to have significantly greater knowledge of employment support than other staff. Social workers were also found to routinely liaise with wider groups including the police and offenders' services, immigration, jobcentres, benefits support and local community support groups spanning a range of potential needs (Allen, 2014;Stromwall, & Hurdle, 2003). Outreach work took social workers into hospitals, jails and communities where long-term goals were created based on the individual's stage of readiness (Dumaine, 2003). To this end, social workers were reported to be adept at multidisciplinary working, and to offer unified and integrated services that enable individuals with mental health needs to improve their social and community functioning (All Party Parliamentary Group, 2013;Stromwall & Hurdle, 2003).
Social workers were reported to implement a spectrum of interventions (All Party Parliamentary Group, 2016). Practical interventions dominated accounts in the literature, such as Priebe, Fakhoury, Hoffmann and Powell (2005) who found that 82% of social workers in London reported that support in, and training of, daily living skills was one of their main roles. Other interventions targeted social functioning with the aim of improving engagement in the community and enabling individuals to enter meaningful vocations (Pahwa et al., 2016;Ramon, 2010;Stromwall & Hurdle, 2003). Social workers used psychological interventions (Davis & Jung, 2012), including counselling (Beresford, 2007;Lang et al., 2011;Peck & Norman, 1999), psycho-education around medication effectiveness and side effects (Davies, 2012;Pahwa et al., 2016) and emotional support to individuals in crisis (Marshall et al., 1995;Raiff & Shore, 1993).
The literature also described the statutory roles of social workers within mental health (Golightley & Geomans, 2014;Ramon, 2010). It illustrated how social workers exercised professional judgement over ethical dilemmas and risk when supporting individuals and families with the most serious needs, spanning safeguarding, domestic abuse, child protection, criminality, homelessness and substance use issues (Goldstein, 1973;Gould, 2016;Rubin & Parrish, 2012). Social workers were reported to require assessment and decision-making skills under circumstances where full information was either not available, was uncertain, and/or within fast-moving and volatile situations (Davies, 2012).
One study by Cree and Davis (2007) highlighted service users' views on the scope of mental health support from social workers. The authors conducted four service user and two carer interviews about the social worker input into their care. They found that both the service users and carers identified that social workers liaised with other services on their behalf, introduced other treatment options, for example Cognitive Behavioural Therapy, and involved family members where appropriate.
The secondary data. This theme was limited to two questions regarding the scope of support service users received in relation to financial and employment advice. Descriptive statistics can be found in Table 4. For both questions, no significant differences emerged, (ds 0.02), suggesting both social workers and CMHNs provided the same level of support.
Overall satisfaction. The CQC questionnaire also included a question about service users' overall satisfaction with their experience of NHS mental health services, using a 10-point Likert scale ranging from 0 (I had a very poor experience) to 10 (I had a very good experience). A t test revealed a significant difference between CMHNs and social workers t(3048) ¼ 3.75, p < .001. Service users on CMHN caseloads rated their experience as significantly higher than service users on social workers' caseloads.

Discussion
Despite decades of debate about the importance of social work in mental health, the profession appears to have made little progress in establishing a clear evidence base for its role. This article reviewed literature on the mental health social work role and provided a new analysis of secondary data on service user perceptions thereof. The discussion considers the implications of the findings for mental health social work going forward, focusing on the importance of developing a clearer role definition which can be understood by all, including service users, alongside a fuller comprehension of the service user perspective of this. The strengths and limitations of the data used for this study are also explored.

Social work today and the service user voice
The review of the literature undertaken for this study indicated that social workers operated within a value-based approach recognising societal influences on the individual, perceived the promotion of self-determination of vulnerable individuals as central to their work and undertook a broad range of support including advocacy, direct interventions and the ability to access others, alongside statutory responsibilities. Social workers were found to recognise the importance of the individual participating as fully as possible in decision-making (Golightley & Geomans, 2014;Herman, 2014;Penhale & Young, 2015;Ring, 2001); to play a key role in creating comprehensive and personalised care plans, reflecting individuals' needs and preferences (Allen, 2014;Raiff & Shore, 1993); and to understand the need to develop trusting relationships to support these ends (e.g. Allen, 2014;Beresford, 2007). These principles are the foundations of current social work training in England, with the ThinkAhead initiative being one example of the drive to promote graduate entry to mental health specialist training (Clifton & Thorley, 2014). Its publicity highlights key features of social work including building relationships with people, providing guidance and therapy, arranging support and care, ensuring people's safety, standing up for people's rights and improving community services. They describe the role of a mental health social worker as someone who empowers individuals through therapy, support and advocacy, building resilience in individuals, their networks and their communities, thus transforming people's wellbeing and improving our society and economy (ThinkAhead.org, 2018).
The evidence presented in this article identifies that within the literature whilst social workers, educators and other professionals are (broadly) able to discern the unique contribution social work provides as part of community teams (see also ADASS, 2018), there is a surprising lack of testimony or articulation of the service user perspective in relation to their role in mental health care. Interestingly, even the Barclay Report of the 1980s on Social Workers' Roles and Tasks (Barclay, 1982) makes no mention of mental health care in their chapter on views of social work. Given the profession's position as advocating for, and empowering, the service user, these findings are puzzling. This is not unique to mental health. Penhale and Young's (2015) review of research spanning service user views of social work in general found a paucity of such evidence but it was notable that evidence specific to mental health services was even scarcer. Two reports that did focus on users' views, although not on mental health services specifically, recorded a range of attributes that service users valued and which they identified with social workers (Beresford, 2007;Penhale & Young, 2015). These studies, which are by no means definitive, mirrored the professional perspective of the social worker's unique contribution and included recognising and respecting diversity, seeing the client as a unique individual with unique needs, being non-judgemental, and being trustworthy and honest.
Despite the paucity of service user-based research, there is also an argument that existing data are not used to their full capability. In this article, secondary analysis of the CQC Community Mental Health Survey data was undertaken, in part to redress the imbalance found in the literature. It enabled a comparison of those supported by a social worker with those supported by a mental health nurse. Perhaps surprisingly, minimal evidence was found to support the views identified in the literature and noted above as being particular to social workers. Indeed, where differences between mental health nurses approaches and those of social workers did emerge, they largely favoured nurses. This merits some reflection: why does the unique contribution of social work articulated in the literature not percolate through to evidence of service user experiences? What is obscuring its visibility?
First, there continues to be widespread misunderstanding of the social work role which may influence service user expectations. For example, ThinkAhead recently commissioned the polling company ComRes to find out what the public thought social workers did. They interviewed 2033 adults online across Great Britain, in March 2017. Key findings included that only 41% thought that social workers were an important provider of mental health support, that the most likely type of support provided by social workers to people with mental health conditions was to assess practical needs (65%) and that only 33% thought that social workers were involved in the detention of individuals under the Mental Health Act (ComRes, 2017). This is not a new debate: that social work struggles to make clear its purpose to the general public has been discussed at length, both at home and abroad (Barclay, 1982;LeCroy & Stinson, 2004). However the implications may be profound. Service user misunderstanding can undermine confidence that social workers can help them, can affect the social worker's own belief in their capacity to make a difference and together form a self-fulfilling prophecy (Legood, McGrath, Searle, & Lee, 2016).
A second reason may be that social work in community mental health is culturally and numerically subsumed within a health-dominated framework. Mental health social workers remain a minority within a medically dominated workforce (Evans et al., 2012) meaning that when teams and services are faced with managing crises in an increasingly austere environment it might become more difficult for social workers to 'argue the importance of . . . a person's right to accommodation, building social networks and buffers, or the use of social interventions' (Woodbridge-Dodd, 2017, p. 3). This view is also supported by evidence from social workers themselves who have described themselves as being isolated within NHS trusts (Morriss, 2016). The same study found that those who did not have social worker managers were described as being unable to make their contribution visible through supervision. This was corroborated by earlier research, albeit with CMHTs for older people, where social workers supervised and managed by non-social workers were reported to feel less well understood and their contribution less valued and supported when compared with those managed and supervised by social workers (Abendstern et al., 2014).
Evidence also suggests that within multidisciplinary teams social workers are increasingly seen as generic mental health professionals whose roles overlap with other professionals more than in the past (Wilberforce et al., 2013). These trends are exemplified in legislative changes, whereby approved mental health professionals have replaced the approved social worker role, although in practice 95% remain social workers (ADASS, 2018). Interestingly, Beresford (2007) reported an expression of concern from service users regarding a possible reduction in the helpful practice provided by social workers in this field with the ending of the approved social worker role. This provides some evidence or suggestion of service user recognition of difference between the approaches taken and roles of different professional groups and a preference for those of social workers.

Study limitations
A number of study limitations must be acknowledged. The literature review was not fully systematic and its findings must therefore be treated with some caution. In particular, the six authoritative textbooks were personally selected and others might have been chosen (e.g. Karban, 2011;Tew, 2011). Data extraction was also limited to the collection of social work attributes rather than delineating the voices from whence these data came. The narrative approach to reporting these data, nonetheless, helped to identify particular dimensions of practice for further analysis via the secondary data. These data, however, also had various shortcomings. First, it is possible that service user questionnaires are not sensitive enough to detect experiential differences between being supported by a social worker or other professional. Additionally, the researchers had no control over what questions were asked in the survey and consequentially their mapping to the literature was approximate. The true distinctiveness of social work is perhaps more nuanced than the survey questions would allow. If there is a distinction to be detected, other research methods may be necessary to draw this out. Second and more specifically, the CQC questionnaire was not part of a controlled experiment and therefore differences in case mix supported by different professional groups that might impact on the findings could not be measured. For example, other research has demonstrated that social workers often work with different groups to CMHNs, including people with the most complex needs and circumstances (Allen, 2014;Huxley & Kerfoot, 1993;Penhale & Young, 2015). One study found that social workers in CMHTs tend to carry caseloads of those with higher levels of severity of mental illness and impairment than CMHNs (Huxley, Reilly, Mohamad, & Harrison, 1998). This is not inconsistent with the fact that fewer of the social worker supported respondents had self-completed the survey. Such a difference in case mix could affect the perceived satisfaction of service users thereby confounding attempts to compare experiences between respondent groups. Third, the CQC data also incorporated a range of different services, including crisis teams, recovery teams and outpatient services. Satisfaction is perhaps more attainable in long-term care, possibly because service users who are involved with a service over a longer period of time develop relationships with their staff enabling them to respond more meaningfully to questions about satisfaction with their input. In the current survey, however, the particular service used by the respondent was not identified. Finally, a significant difference was found between when service users were last seen by a social work compared to a mental health nurse, with those supported by a mental health nurse having been seen more recently. Although it is not clear from the data why this was the case, its occurrence could also have detrimentally affected their satisfaction, whether because they were dissatisfied with the level of contact received or simply because they could not remember the nature of the contact due to the time elapsed since it had occurred.

Conclusion
The mixed methods approach used for this study had both strengths and weaknesses. The former lies in its ability to access and analyse existing large-scale data that would not otherwise be available. Its limitation, however, is whether the data source was sufficient to illuminate the social work role, which has been shown to be notoriously difficult to articulate. Future research will need to pay heed to these limitations to shed more light on whether there are any true distinctions between the experiences of service users supported by social workers and other professionals. New research funded by the NIHR School for Social Care Research is currently underway which aims to address this through an investigation of service user and staff perspectives of the value of the social work role within CMHTs using a variety of tools and methods. It will be important to identify any distinctions found between service users supported by social workers and other CMHT practitioners and explanations for this. In addition, empirical research to understand the exercise of mental health social work in practice is required to compare with the literature expounding its optimal attributes. Such research might usefully consider the voices of social workers themselves as well as service users and carers. Whilst the focus of this article has been on social work in mental health it is worth commenting that the contribution of social workers for other service users (e.g. older people) and in other settings (e.g. intermediate care) is also difficult to articulate. Thus social work in general as well as mental health social work in particular is in need of research which helps to articulate its role and value.

Authors' note
Jane Hughes is now retired from the University of Manchester, UK.

Ethics
Ethical approval was granted by the North of Scotland (2) Research Ethics Committee: grant number: 17/NS/0127.