In the unmet needs theory of responsive behaviours, the person has a need that can’t be expressed and isn’t being met. A useful comparison is infants. Infants might cry or act in a certain way to get a response because they cannot communicate what they need.

Someone with moderate to severe dementia may also not be able to say what their needs are, because dementia affects the ability to communicate, use language and organize thoughts. If someone becomes agitated, screams, yells or hits, this might be a form of communication. They are trying to say something to the caregiver or to the people around them. It could be an expression of physical pain, loneliness or understimulation. They may need something or be bored. It could also be that they are uncomfortable.

According to the progressively lowered threshold theory of responsive behaviours, all of us have a point at which we can become very agitated or bothered by something, whether it’s in the environment or internal. We all have this threshold, and some people have a higher threshold while others have a lower one. For people with dementia, the theory is that the threshold becomes quite low. Their ability to deal with stress in the environment decreases as the dementia progresses. It doesn’t take much for that person to become overwhelmed and then potentially act out in a behavioural or emotional way.

The learning theory considers the behaviours, the triggers for those behaviours and how we respond to them. This model draws on basic psychological learning theory and concepts like operant conditioning. These are psychological terms that describe how caregivers respond to the behaviours of someone with dementia and how those responses might unintentionally perpetuate them.

For example, if someone is calling out repeatedly, the natural response from a caregiver, who wants the person to settle down and be comfortable, is to give that person attention. The person may settle down, feel much better and stop calling out. But when the caregiver leaves to do something else, the calling out may resume. The caregiver then comes back and gives the person attention again.

In this way, the behaviour is being reinforced. The act of soothing the person, in a sense, rewards the calling out. This is an example of learning theory and how behaviours can be maintained because of our responses, which can be natural and very caring but sometimes perpetuate the problem.