What causes aggressive behaviour?

Aggressive behaviour might be a person’s way of trying to achieve what they need. Take a look at what these needs might be.

People with dementia have the same needs we all have. These include the need to be comfortable and free from pain, able to interact with other people, to feel engaged and stimulated and to feel well in ourselves.

However, people with dementia may be unable to recognise their needs, to know how to achieve them, or to let other people know what it is that they need. This may cause them to act in ways that others might find challenging, including aggressively.

The aggressive behaviour might be the person’s way of trying to achieve what they need. It may be a sign of a need that isn’t being met or an attempt to communicate it.

Understanding what is causing the person’s behaviour can help you to find a solution. Some possible explanations for aggression are listed below. It could be related to the person’s physical needs (including health problems), social needs (how they’re relating to other people) or psychological needs (their thoughts and feelings).

Physical needs

  • The person may be in pain, unwell (including having an infection) or in discomfort (including being constipated or thirsty, or from sitting for too long).
  • Side effects of medications, or taking too many, may mean that a person becomes more confused and drowsy. They may be less to able to meet or communicate their needs as a result.
  • There may be something about the environment that is wrong for the person with dementia. It may be too busy and overwhelming (for example, with too many people around), or too hot, cold, noisy, or bright. Alternatively it might not be stimulating enough (for example, with nothing for the person to do).
  • Poor eyesight or hearing can lead to misunderstandings and misperceptions (where the person mistakes what they see or hear for something else).
  • Hallucinations (where people see things that aren’t there) or delusions (where people strongly believe things that aren’t true) can be confusing and frightening. This can lead the person with dementia to respond to them in an aggressive way.
  • The person’s dementia may have affected their judgement and selfcontrol.
  • They may have lost their inhibitions or have less awareness of what kind of behaviour is appropriate.

Social needs

  • The person may be feeling lonely. They may not spend much time with others, or when others are there they may not feel included or valued.
  • They may be bored, not have much to do or not have much to stimulate their senses (sight, hearing, touch, smell and taste). There may be different professionals coming in to care for the person, who have different approaches or routines. This may be confusing for the person.
  • The person may not like or trust a particular care professional.
  • The person may be trying to hide their condition from others.

Psychological needs

  • The person may feel that their rights are not being respected or that they are being ignored. This may be due to misperceptions, memory difficulties or problems processing information, but it may also be true.
  • For example, they may feel that they are being stopped from doing things they want.
  • They may become frustrated at not being able to complete tasks, such as making a cup of tea.
  • They may have depression or other mental health problems.
  • They may misunderstand the intentions of the person caring for them. For example, personal care may be seen as threatening or invading their personal space. Accepting help with intimate tasks such as washing, dressing or going to the toilet can be distressing and stressful, especially if you don’t understand what is happening.
  • Other people may assume that the person with dementia can no longer do things for themselves or leave them out of decisions that affect them. This can cause the person to become angry because they are not being listened to or are being ignored.
  • The person may feel threatened by an environment that appears strange or unfamiliar. They may think that they are in the wrong place or that there are strangers in their home.
  • They may have difficulty understanding and working out the world around them, and may experience a different reality from others. For example, if they believe that they need to collect their children from school, they may become aggressive if they are stopped from doing so.