Supporting someone living with dementia often means navigating a world of different professionals, different appointments and different perspectives. It can also mean hearing the same person described in very different ways depending on who is speaking.person.
A doctor might refer to Stage 5 on the Global Deterioration Scale. An occupational therapist might talk about Allen Level 4. A dementia care specialist might describe someone as being in an Emerald GEMS State.
This can feel confusing — even contradictory. If they are all talking about the same person, why can’t they agree on a single description?
The answer is that they are not disagreeing. They are simply looking at different things.
Different Tools Answer Different Questions
Dementia affects far more than memory. It changes thinking, communication, movement, emotional regulation, daily living skills and relationships. No single assessment can capture all of that — which is why several tools exist, each designed to answer a specific question.
The Global Deterioration Scale (GDS), developed by Dr Barry Reisberg, describes dementia across seven stages — from Stage 1, where there are no noticeable changes, through to Stage 7, which represents very severe decline. It focuses on how far the dementia has progressed, making it particularly useful for medical teams tracking the overall trajectory of the condition.
The Clinical Dementia Rating (CDR) takes a slightly different approach. Rather than a single stage number, it looks at several specific areas of life — memory, orientation, judgement, community involvement, home activities and personal care — and rates each one separately. This gives clinicians a more nuanced picture of how dementia is affecting day-to-day life across different domains.
The Allen Cognitive Levels, developed within occupational therapy, shift the focus from decline to function. Rather than asking how bad is it?, the Allen model asks what can this person do? It describes six levels of functional cognition, helping occupational therapists plan meaningful activities, consider safety and adapt environments to support independence.
The GEMS States, developed by Teepa Snow as part of Positive Approach to Care, are different again. GEMS is not a clinical assessment — it is a framework for connection and support. Each gemstone represents a pattern of retained strengths and changing needs, helping carers and care partners understand how best to communicate and respond in the moment.
The clinical tools — GDS, CDR and Allen Levels — tend to focus on what has been lost: the deficits, the decline, the things a person can no longer do. That is useful information, but it only tells part of the story.
The GEMS States offer a different lens entirely. Rather than measuring loss, they ask: what remains? What does this person still respond to? How can those supporting them connect and communicate most effectively today? GEMS is not a clinical assessment and would not typically feature in a formal multidisciplinary meeting — but for carers, family members and care staff, it can be one of the most practical and human frameworks available.
So What Happens in a Multidisciplinary Team Meeting?
If different professionals use different scales, how do they communicate with each other — and how do they reach a shared understanding of what is happening for the person?
The answer is that they do not need to agree on a single number or scale. In a multidisciplinary team (MDT) meeting, each professional contributes information from their own area of expertise. The doctor might discuss the stage of disease progression. The occupational therapist might describe what the person can and cannot do safely at home. The dementia specialist might focus on communication strategies and retained strengths. Other team members might contribute information about mood, mobility, behaviour or wellbeing.
Together, these different perspectives build a much richer picture than any single scale could provide alone.
Someone might be described as Stage 5 on the GDS, functioning at Allen Level 4, and showing many characteristics of an Emerald GEMS State — and all three of those descriptions can be accurate at the same time, because each one is telling you something different about the same person.
The Most Important Assessment
Assessment tools are useful — but they have limits.
A stage, score or level can provide helpful information. It can guide conversations, shape care plans and support professionals to work together more effectively.
But no scale can fully describe a human being.
The most meaningful understanding of anyone living with dementia comes from knowing who they are — their history, their personality, their preferences and what still matters to them. That knowledge does not come from a scoring tool. It comes from time, attention and a genuine commitment to seeing the whole person.