What does “complex” mean in mental health care? The term ‘complex’ is widely used by mental health professionals, but it can mean different things in different contexts. Sometimes it refers to difficulties that are chronic or severe. For example, ‘complex trauma’ usually describes exposure to multiple or prolonged traumatic events, in contrast to ‘simple trauma’, which is typically used to describe a single, identifiable traumatic event.
At other times, ‘complex’ is used to indicate the presence of co-occurring conditions. A young person may be described as having a ‘complex presentation’ if they have received more than one diagnosis. Related terms such as ‘complex mental health conditions’, ‘complex care’, ‘complex needs’ and ‘complex support services’ are also common, although definitions vary. Often, the word is used to signal that multidisciplinary input may be needed.
I have become increasingly aware of the challenges associated with this language. Although I work in the field of feeding and eating disorders, I do not think these concerns are limited to young people with eating difficulties. My impression is that describing presentations as ‘complex’ can sometimes restrict access to appropriate interventions, lower clinician confidence and create additional barriers for young people and families seeking support. Rather than promoting holistic, joined-up care, the term may inadvertently make care feel harder to access. In this short commentary, I raise this concern and offer some reflections.
Potential effects of describing a presentation as ‘complex’
My clinical observations suggest that using the term ‘complex’ can have several unintended consequences. These effects do not arise in every situation, but I have encountered them often enough to consider them significant.
1. It can close doors to care
Describing a presentation as complex can, in some circumstances, limit access to appropriate services. A young person may be experiencing a relatively common mental health difficulty for which local support is available. However, if they are also neurodivergent or have an active medical condition, they may be labelled as complex and therefore considered outside the referral criteria for the relevant service.
In feeding and eating disorder services, for example, ARFID is sometimes described as complex. This can leave families struggling to access community eating disorder services, even when those services usually have the skills and competencies needed to provide appropriate multidisciplinary assessment, advice and care.
2. It can increase risk
When access to care is delayed or denied, difficulties may go untreated. This can increase risk for the young person, worsen impairment and place greater pressure on families and others involved in their care.
3. It can feel destabilising for young people and families
When young people and their parents or carers hear that professionals regard their difficulties as complex, this can be unsettling. They may wonder whether recovery is possible, or whether their needs are too difficult for clinicians to help with.
4. It can reduce trust and confidence in local care
This uncertainty can contribute to diminished trust in the clinicians already involved. Families may lower their expectations of what can be achieved locally and may feel compelled to seek alternative, sometimes out-of-area, more ‘specialist’ care.
5. It can lower clinician confidence
Clinicians may also feel less confident when asked to work with someone described as complex. The label can imply that the work lies outside their usual skills or experience, or that there is a greater likelihood of not getting things right.
What the word ‘complex’ evokes
These potential consequences have been described to me by families, young people and colleagues. This led me to consider what the word itself might evoke.
Dictionary definitions of ‘complex’ usually include two related ideas: first, that something has different but connected parts; and second, that it may be difficult to understand or work out because of those many parts. ‘Complicated’ is often listed as a synonym. For me, words such as ‘difficult’ and ‘complicated’ can carry negative overtones, perhaps suggesting something that is best avoided.
To test whether this was an overly gloomy interpretation, I conducted a brief, informal, one-question vox pop. I did not provide any clinical context. I simply asked: “What comes first to mind when you hear the word ‘complex’ used to describe something?” I then asked an AI helper to identify the main themes in the responses.
Three themes emerged. Interestingly, they were more balanced than I had expected and included some reassuringly positive interpretations. Each theme also resonated clearly with existing models of the development of difficulties, proposed care pathways and current policy directions towards integrated care.
Theme 1: Interconnected parts
The first theme was ‘interconnected parts’. Responses suggested that complex things involve multiple interdependent elements, where a change or difficulty in one area can affect the whole. In this sense, complexity refers to intricate strands or components that interact in ways that may not be immediately obvious.
This theme maps closely onto increasing calls for intersectional, person-centred care. It reminds us to avoid viewing an individual as a collection of diagnoses. Instead, we should approach them as a person managing several simultaneous challenges, which may interact with one another and contribute to the development or maintenance of difficulties. Crucially, these interactions may not be immediately apparent, so the whole picture needs to be considered when addressing a specific presenting concern.
Theme 2: Hard to understand or solve
The second theme was ‘hard to understand or solve’. Here, responses suggested that complexity can make something difficult to unpack, untangle or resolve. It may require more time, thought and care because it is not straightforward and may be more complicated than people initially realise.
I had a mixed response to this theme, as ‘complicated’ is not a word I would usually choose. However, I welcome the broader sentiment. I have long believed that comprehensive assessment — involving time, thought and care — is essential to developing a good understanding of a young person’s situation. This understanding can then be discussed and refined with the young person and their family. Once a shared understanding is reached, the path towards change becomes clearer.
Theme 3: Nuanced and multifaceted
The third theme was ‘nuanced and multifaceted’. In these responses, complexity was understood as involving layers, nuance and depth. It could describe something positive or negative, but it could not be reduced to a single explanation or simple solution.
This theme aligns with welcome policy shifts towards joined-up, integrated care around an individual’s needs. Where there is no single explanation or simple solution, clinicians need to collaborate and communicate with one another, and with the family, to provide optimal care. This also helps reduce the burden on families to advocate repeatedly for their own support needs.
Moving towards more descriptive language
Perhaps the term ‘complex’ is not entirely problematic. My informal vox pop highlighted some useful ideas: interconnectedness, nuance, and the need for time, thought and care. However, the unintended consequences remain important.
Given the barriers and anxieties that can be associated with the term, I wonder whether we should be more specific and descriptive in our language. Rather than saying that a young person is complex, or has a complex presentation, we might explain what we mean in more accessible terms.
For example, instead of describing an autistic young person with Crohn’s disease and significant anxiety as complex, we might say:
“There are several important things going on for your child, and each of them may affect the others. To make sure she and your family receive the right support and treatment, it would be helpful for us to work closely with you and with relevant healthcare colleagues, so that care is joined up and appropriate.”
This is admittedly longer than saying that a child is complex or has a complex presentation. However, it is also clearer, more respectful and more consistent with person-centred, system-wide, integrated care.
About the author
Dr. Rachel Bryant-Waugh is an experienced eating disorders clinician and researcher, based at the Maudsley Hospital and King’s College London. She is recognised internationally as a leading expert on ARFID, having sat on both the DSM-5 and the ICD-11 diagnostic workgroups and maintained a high level of related activity since its introduction. Rachel was National Clinical Adviser for the establishment of England’s young people’s Eating Disorder Pathway and led the National ARFID Pilot. She has won national and international awards for her contributions. Rachel has a longstanding interest in working with autistic people with eating disorders and is passionate about learning from people with lived experience.