The BBC series Rev was brilliant but at times silly and, doubtless, wildly inaccurate. But there was one memorably authentic scene in which the vicar, Adam Smallbone, really is at rock bottom. Tears roll slowly down his cheeks as Smallbone, played by Tom Hollander, lies slumped on his dishevelled bed. Exhausted and alienated from his wife, Smallbone clings on – just – to his faith by reciting the Beatitides. The moment serves as a momentary glimpse into the apparently unusual concept of clergy depression.

When the Archbishop of Canterbury addressed the debate on clergy wellbeing at the General Synod earlier this month, he made headlines – but he also won the hearts of many a church minister when he recalled that he was at his most stressed when he was a parish priest.

'The hardest work I've ever done and the most stressful was as a parish priest – mainly because it was isolated, insatiably demanding and I was on the whole working without...close colleagues, particularly in the first few years,' Justin Welby said.

He was speaking in a debate for which a background briefing described how the Church of England Experiences of Ministry Survey (EMS), in collaboration with Kings College, assessed clergy wellbeing in four ways: 'emotional exhaustion and depersonalisation (two measures of burnout); general physical health; and psychological detachment'.

Stress and mental health are increasingly in the news, with everyone from Princes William and Harry to journalists describing episodes of anxiety or depression. But for some reason the mental health of clergy has often been overlooked – until now.

'The EMS, reaching a nationally representative sample of ordained ministers, found that clergy, as an occupational group, appear to report higher levels of emotional exhaustion than many other professional groups,' said the briefing for synod, the Church's parliament.

Another speaker in the debate was Stephen Cottrell, the Bishop of Chelmsford, who said that his diocese has introduced 'clergy wellbeing days' which are 'very well received and well resourced and are slowly beginning to change the culture'. He went on to pose the question of 'how it feels to be a bishop' and, strikingly, said: 'Sometimes it can be a very heavy weight to carry, and sometimes it can feel like you are carrying it on your own...and it can sometimes be a lonely role.'

Asked to expand on this later by Christian Today, Bishop Cottrell explained: 'I have always believed that despite the need for clergy to observe proper professional boundaries, Christian ministry is not quite a profession in the way most people usually use that word. We live in the communities we serve. We can never be completely off duty. We are very available. We are the recipient of all kinds of projections and expectations, many of which can never be met and some of which shouldn't.

'Nevertheless I love being a priest and I love being a bishop because for me ordination has made me more the person I am meant to be. This is always how vocation works. It adds to and completes who we are.

'But it is also for these reasons of availability and visibility that ordained ministry can also be hard. Some of us sometimes get the balances of ministry wrong and any position of leadership brings a certain loneliness since there are some decisions that can only be made at the place where the buck stops. The requirement of confidentiality also means that the reasons for a decision cannot be shared widely. Consequently, episcopal ministry can sometimes feel like a heavy load, and for this bishop it also means that I try to make supporting the well being of the clergy I serve a priority. But since I know a man who is good at bearing heavy loads I do not get downhearted.'

It is the unique nature of the job that was also highlighted by the background briefing. 'For clergy, the boundaries of work (ministry) are not clearly defined in time, space, activity or relationship,' it said. 'Moreover, as is to be expected, spirituality is clearly prominent in the ministers' narratives, with theological discourses around concepts such as sacrifice and failure influencing their understanding of wellbeing.'

As Canon Ailsa Newby, Canon Pastor at Ripon Cathedral, tells Christian Today: 'Most clergy find ministry an immensely fulfilling vocation. The stresses of clergy life come paradoxically from that sense of vocation: there is always more to be done then there are hours to do it and the boundaries between personal life and ministerial life are very easily fudged. It is so important to ensure that priests are encouraged to take the down-time they need and encouraged to understand that that will make them more effective pastors. No one is well-served by a burnt-out cleric.'

This is echoed by Canon David Isherwood, a former inner-city vicar, including at Holy Trinity Clapham. 'From inner-city to rural parishes there are stressed out parishioners – men, women and children stressed – mainly – by their work, families, expectations, shattered dreams. What makes clergy different is a series of factors including loss of identity, authority and "place," especially in retirement.

'We take on too much, and are perhaps afraid of not doing so, because the myth of omnicompetence runs deep in the marrow of many clergy. It leads to an undervaluing of the particularity of gifts of ministry in lay people and crucially in themselves. I had to learn quickly what Bishop Ian Cundy once told me: "In all ministry, I need you and you need me." Not to acknowledge that fundamental principle of ministry can lead to depression and frustration. I know it does.

'In the recent past there has been an undermining of the role and place of imaginative, quality pastoral care and counselling by those in authority over us. If the well-being and the skills clergy need to acquire to live joyful and contented lives is as important as growth, then first, national standards need to be identified, and secondly, money and funds need to be identified to support fewer clergy in larger parishes and among smaller or larger congregations.'

Meanwhile Dr Yvonne Warren, for 20 years a Christian psychotherapist in Coventry who is married to a clergyman, told the debate that she has 'many concerns which have made me feel so passionate' about the subject. She highlighted the plight of rural clergy, who often have five to 10 parishes to look after, stretching them thinly. 'Like any good organisation, unless we care for the workforce, we are all about doing and nothing about being,' she said. 'I have a real concern about all that is expected of our clergy...in the work that we're asking them to do, in what now is no longer a Christian country...In my work as a therapist I'm finding many clergy are burnt out...suffer from mental health issues and families just about at the end of their tether and many clergy going off sick.'

Another contributor was Canon Rebecca Swyer, a deacon in Chichester who is married to a priest, again outlined several initiatives in her parish that have been introduced to foster clergy wellbeing, including appointing a full time officer for pastoral care and counselling for clergy. This operates with confidentiality, with clergy able to self-refer without consulting their archbishop, and sometimes then going on the be referred to professional counsellors. 'Ordained ministry brings the greatest joy, but also sacrifice, guilt and stress,' she told the synod.

Swyer, the Director for Apostolic Life in Chichester who helps accept and train clergy, tells Christian Today: 'A sense of calling to diaconal or priestly ministry is only part of the selection process because the Church has realised that candidates need also the sort of character and disposition that is able to undertake ordained ministry. Over recent years a number of surveys and pieces of research have been done on clergy at various stages of their ministry and looking at how many have ended up having breakdowns, leaving full-time ministry and also related to the sorts of challenges they face.'

Swyer's special area of responsibility is for curates. 'As you'd expect, those newly ordained are usually full of enthusiasm and because of that will often end up doing too much and will need to reassess their pattern of ministry,' she says. 'One of the key parts of curacy is therefore establishing a sustainable pattern of ministry for the future, which means a ministry underpinned by a deepening prayer life and pattern of worship; ongoing engagement with theology and scripture as part of their own active discipleship; healthy work pattern such as work and home balance, self-aware and with the capacity to keep appropriate boundaries.'

Key issues she has identified for training clergy include the idea that ministry isn't just a job, but an all-encompassing vocation. 'You are ordained 24-7 and this impacts on how people relate to you and you to them. For example, if a priest goes to the supermarket in his parish, he or she will commonly end up having conversations about faith or God as they go round the aisles. As they usually live in the parish and have responsibility for every soul residing there, it is very hard to be off-duty.'

Secondly, because ministry is all-encompassing there is also some tendency for this vocation to take over life. 'It can put pressure on marriage and family life if ministry is given so much time and priority,' Swyer says. 'Something I frequently talk to curates about is the balance of the different vocations God has called them to, such as a husband or wife, parent or child. Vocation to ordained ministry has to sit alongside these and not 'squash' them...We sometimes say that ordained ministry is sacrificial, which it is as you're offering your life to God's service. However, this doesn't mean setting aside everything else in life and carrying everything yourself.

Next: 'Ministry doesn't have a clearly set down work pattern and even the best laid plans – or day off – have to be abandoned or adapted if someone is dying.'

Fourthly, there is a sense that 'the work is never done because clergy are engaging in God's mission to proclaim the gospel and bring all to know, love and follow Jesus Christ. Clergy frequently feel guilty that they're not doing enough...Guilt can be linked to some feelings of failure. I've been interested how quickly after ordination curates can start having such feelings of guilt and feel pressure that they should be "doing more". They can feel guilty about taking time for prayer and retreat, which are essential and also of course follow the pattern of Jesus in his ministry. Clergy can tend therefore to overwork, which potentially can lead to burnout. This is why stressing the need for a sustainable pattern of ministry is so important.'

And finally, 'if you're ordained, your ministry in a real sense isn't your own, but belongs to the church. You feel the initial sense of calling, but the church has to affirm that and you are ordained, sent and licensed under the bishop's authority. Public ministry is something clergy have to learn to inhabit. They represent in a real way the church, Christian life and God. People often put clergy on pedestals and expect that they'll be a Christian role model, which we hope they will be.

'However, people can then forget clergy are also normal human beings. The unrealistic expectations that can arise from this can mean that when a member of clergy - or their family - is struggling or ill they can feel they have to keep this hidden.'

In time, it can be hoped that dioceses have the resources in place to support ministers and prevent the sort of loneliness that Archbishop Welby described, and the sort of burnout that afflicted the fictional Adam Smallbone.

For as Rev – and indeed the recent, stunning BBC drama Broken – show so well, clergy are indeed 'normal human beings'. Now, thanks to an uncharacteristically interesting discussion at synod, their very real, every-day stresses and strains are finally being debated, examined and addressed.