The Tail

Focusing on the people at greatest risk

Most diabetes care is designed around populations.

We measure how many people achieve recommended HbA1c targets, identify those above target, and introduce interventions intended to improve outcomes across the group.

This is important. But diabetes psychiatry suggests starting somewhere different.

Moving further into the tail

As HbA1c rises, the number of people becomes smaller. At the extreme end of the distribution — for example, people repeatedly experiencing HbA1c levels above 100 mmol/mol, recurrent diabetic ketoacidosis (DKA), or other severe diabetes events — we encounter a relatively small population carrying a disproportionate amount of medical risk.

We describe this as the tail.

The argument for focusing here is not that these people have “worse diabetes”.

It is that, as we move further into the tail, conventional explanations for poor diabetes outcomes increasingly become insufficient.

Someone may know perfectly well how to use insulin. They may have received diabetes education repeatedly. They may have access to technology and specialist services.

Yet the dangerous pattern continues.

At this point the clinical question needs to change from:

“How do we improve diabetes management?”

to:

“Why does this particular person continue to experience such extreme diabetes risk?”

Risk becomes concentrated

Extreme diabetes outcomes are rarely distributed evenly across the population.

A relatively small group of people may experience repeated DKA admissions, persistently extreme HbA1c, recurrent severe hypoglycaemia or repeated emergency healthcare use.

This matters clinically.

If serious complications, hospital use and premature mortality are concentrated within a relatively small population, identifying and understanding that population creates an opportunity for much more intensive intervention.

Instead of providing a little more treatment to a very large population, we can provide substantially more treatment to the people carrying the greatest risk.

The tail is not a diagnosis

People arrive in the tail for very different reasons.

Depression, trauma, personality difficulties, eating disorders, psychosis, neurodevelopmental differences, substance use, cognitive difficulties, social adversity and difficult relationships with healthcare can all contribute.

Sometimes the principal problem is not conventionally psychiatric at all.

What people share is an outcome — unusually high diabetes risk — rather than a single psychological explanation for it.

This is why diabetes psychiatry begins with detailed individual formulation rather than assuming that everybody with the same HbA1c or number of DKA admissions needs the same intervention.

Finding the people we normally lose

There is another reason for starting with the tail.

The people at greatest risk are often those least able to access conventional psychological or psychiatric treatment.

They may miss appointments, disengage, struggle with regular weekly therapy or move repeatedly between diabetes, emergency and mental health services.

Waiting for this population to present successfully to a traditional mental health pathway risks selecting precisely the people who are already able to engage.

Diabetes psychiatry therefore reverses the process.

Risk identifies the population.

The service then takes responsibility for understanding why that risk persists and what might change it.

The Tail therefore leads naturally to the next question:

What is maintaining this person's current situation?

That requires us to understand the HEAT surrounding their diabetes — and ultimately to find the lever capable of shifting it.