Mental health and physical illness: what’s the role of liaison psychiatry?
- May 28, 2019
Discussions about services for people with co-existent physical and mental health problems usually start with a brief account of how common that state of affairs is, and how important it is. Fair enough, but there’s another step in the discussion: how do you decide who is best placed to respond to the needs of the people affected? Of course clinicians who specialise in physical health should know something about mental health and vice versa: my question is what to do when help is needed from specialists in this so-called co-morbidity? And more specifically, what’s the role of liaison psychiatry?
To begin at the beginning…
Below is a schematic representation of a clinical service, pictured as a simple care pathway. It acknowledges that at each stage some people will not be referred on or will refuse referral, some accept referral and do not attend, and some attend but drop out early. Also at each stage there are some who complete treatment at each level but do not improve. These groups are represented on the right.
The pathway also acknowledges, in line with standard thinking about stepped care, that some people present with such severe and complex needs that they should be referred directly to a special service.

In the UK, brief psychological therapies are usually delivered in primary care through a service known universally by the acronym IPAT (pr. eye apt) and in secondary care by a range of services, most typically clinical health psychology, or psychiatric nurse therapists working in liaison mental health services.
The numbers who move along the branches of this pathway into the complex/severe end are huge. To take one example – figures from NHS Digital indicate that only about a third of those referred to IAPT for a talking therapy complete the course of treatment and of these only just over a half have “moved to recovery” by the end of treatment. We know from other research that relapse rates after brief therapies are high – up to 50% over the next 1-2 years.
So…the pathway above is right to indicate the need for a specialist service for complex and severe cases. What are the features of such cases? The answer is – no two cases are the same. Here’s a list of some of the features of complex and severe problems.
1. Diagnostic complexity (physical health)
- Multiple or persistent severe symptoms that don’t fit standard diagnostic categories (including don’t fit standard MUS categories like fibromyalgia, CFS) or encompass multiple diagnostic categories
- Multiple drug treatments including opioid or equivalent analgesia
- Multiple physical diagnoses, including some validated (so both significant LTC and MUS)
- Erroneous physical diagnosis assigned in past or by 3rd parties
- Disability out of proportion to physical disease severity
- Major non-adherence or misuse of therapeutic regime, including induced illness, with serious physical consequences
2. Diagnostic complexity (mental health)
- Illness conviction, especially non-affective – can sometimes have a delusional quality, sometimes shared by close others
- Suicidal and related thinking, self-harm history or current risk
3. Organisational complexity (healthcare)
- Frequent unscheduled attendance – GP surgery; ED; other healthcare
- Recurrent unscheduled acute admission
- Recurrent unwarranted physical investigation
- Multiple healthcare providers
- Drop out from or failure to respond to first line treatment, with persistent problems
4. Organisational complexity (social care)
- Receipt of benefits dependent upon non-recovery
- Various forms of assisted living for functional disabilities
5. Social complexity
- Wider social dysfunction – tension or conflict with others, impoverished illness-centred social network – having an impact on health or healthcare that acts as a barrier to effective brief psychological therapies
- Children or others as enmeshed carers
- Involvement in long-running and contested litigation or complaints related to health or healthcare
The origin of liaison psychiatry and the fuel for its growth in the UK (until recent years) was the demand for expertise in the management of such cases.
However, not only does a comprehensive service need a component to deal with chronicity/complexity/severity, it also needs to be able to offer integrated care – across primary and secondary care and between the various components of mental health care. So…what are the characteristics of integrated care? Here’s another list.

All this points to a (to my mind) relatively obvious conclusion. Liaison psychiatry services have an important role in the care of people with mental and physical co-morbidity and, at least in secondary care, it would be best if services were arranged so that IAPT, clinical health psychology and liaison psychiatry were brought together in a genuinely-integrated multidisciplinary service. There are barriers to that development – professional resistance is one, and in my experience mainly from clinical psychology; in recent times liaison psychiatry services have been swamped by the acute/urgent component of liaison work, not least because of NHS England policy; manpower shortages and funding limitations consequent on government policy – all play a part. It would be great to see this practical and basically cost-free improvement to care adopted as a national strategic priority by all the key interested parties.