Behavioural effects

Brain injury can have a profound impact on how a person feels (emotions) and acts (behaviour). It helps to understand how their behaviours may have changed and how to manage those changes.

Topics in this section include:

Aggression, anger & frustration

In the acute stage of recovery after a brain injury, a person may display uncharacteristic aggressive behaviour if they are scared, frustrated, or confused. This usually happens when the injured person is not yet consistently aware of their situation (the injury and its consequences) and surroundings (where they are, what day or month it is, etc.). Aggression can show itself in a variety of ways, including:

  • Damaging or destroying objects
  • Excessive swearing
  • Threatening harm to others
  • Inability to self-monitor
  • Verbal, physical attacks

Episodes of aggression often come on very quickly and tend to pass within minutes. Aggression is upsetting for both the person exhibiting it and the caregivers or family members who witness it. Some aggressive behaviours can be risky to a person’s safety. That’s why it’s important to take steps to help the survivor manage aggression.

  • Explain what you are doing before you do it. This will eliminate surprise and reduce fear/stress about the action
  • Identify and eliminate/reduce triggers for aggression (antecedents) when possible
  • Keep the amount of stimulation in the room (e.g., light and noise) low
  • Redirect to calming activities or take the person to a quiet place if they are feeling confused, angry or scared
  • Use calming tactics such as deep breathing or meditation

Coping with physical aggression

If their episodes of aggression continue or safety is a concern, you should consult a behavioural therapist.
If your friend or family member is being physically aggressive with you or others (hitting, kicking, throwing objects, etc.), you will need to learn how to de-escalate the situation as best as possible. The most important things to do in a situation such as this is to avoid confronting the person or arguing with them, try not to yell, and do not become physical. Instead, walk away from them if they are becoming violent.

When the incident is over, focus on the person and ask how their feeling, what they would like to talk about, and actively listen to them when they speak.

These situations are going to be scary and upsetting for you. It’s important that you also have an outlet where you can talk about what happened and how it made you feel. You can reach out to friends/family members or speak with a licensed therapist . You may also discuss the aggressive episodes with the person’s healthcare providers and ask for their recommendations.

It is common for people living with brain injury to get frustrated, angry or irritated more often or more quickly. This can lead to yelling, cursing, threats, destruction of property and physical outbursts.

These episodes of anger or an increase in irritability can be triggered by:

  • Confusion
  • Frustration with a task that is harder than it used to be
  • Fatigue
  • Misunderstanding another person’s intentions
  • People telling them what to do or pointing out mistakes
  • Too much stimulation (e.g., light, noise, and movement)

If your friend or family member is experiencing periods of anger or irritability, try some of the following coping methods:

  • Engage them in calming activities – listening to music or reading are some examples
  • Practice deep breathing with them
  • Remove them from the situation and go to a more calming location
  • Work with a doctor who is familiar with acquired brain injury and emotions on some calming methods and communication strategies. Cognitive behaviour therapy can provide support and tools to help manage anger/aggression and understand why they are having these reactions.
Frustration will be caused by different things for different people. For example, it can come from not being able to complete a task or being annoyed with other people or self-criticizing. When someone is frustrated, they may give up on tasks, avoid things because they are too hard, or have emotional outbursts.

  • If your friend or family member is experiencing frustration, ways you can help them cope with it include:
  • Celebrate their successes, especially if they complete a task that used to frustrate them, or they have made improvements
  • Do challenging tasks for only short periods at a time or with scheduled breaks
  • Encourage them to take slow, deep breaths as a calming mechanism
  • Have a quiet place they can go when they are feeling frustrated
  • Identify what makes them frustrated. While you may not be able to entirely avoid causes of frustration, understanding what causes them to feel that way is the first step in learning to cope with it


Anxiety stems from feelings of worry and fear. After a brain injury, people commonly worry about recovery being too slow, getting back to school or work, not having enough money, and relationship difficulties. Anxiety may lead to unhelpful behaviours, such as avoiding places or situations, re-checking things excessively, and asking the same questions over and over. Anxiety can also lead to panic attacks. Panic attacks (sudden, intense fear and physical sensations like rapid heart rate, shallow breathing, and sweating) – can be brought on by overwhelming situations or emotions, a person’s thought process, or by upcoming events/appointments. Some ways for a person to cope with anxiety include:

  • Developing routines that are clear and able to be used repeatedly
  • Medications
  • Participating in counselling geared toward anxiety (e.g. cognitive behavioural therapy and mindfulness)
  • Practicing slow, mindful breathing
  • Redirecting to a familiar place or activity that makes the person feel safe and calm
  • Scheduling “worry appointments” so the person can contain their worry to a time and place of their choice (e.g., after breakfast) rather than having worries pop into their mind when they are trying to do other things. One way to have a worry appointment is in a journal. You can also offer to be sounding board for your friend and family member

It’s important to be patient. Anxiety is deeply personal and emotional.

Some anxiety after brain injury is normal. After all, capabilities and daily living has changed for them. When anxiety becomes difficult to control and interferes with their sleep, daily activities or relationships, mental health treatment (e.g., cognitive-behavioural therapy) may be necessary.


Brain injury comes with a wide variety of changes and people often can’t do the things they would normally do. This can be incredibly difficult to cope with for both you and the person with a brain injury. They may even begin experiencing denial. They don’t recognize how serious their injury was and how it continues to impact them. A brain injury can also impair a person’s ability to monitor and judge their own performance. They may become angry or frustrated, place their blame for their challenges on someone else, or engage in risky actions to ‘prove’ that they haven’t been affected.

You may have to keep an eye out for dangerous behaviour that would put safety at risk. While you shouldn’t argue with the person (arguing if often counterproductive), you can try to redirect them to new activities. Cognitive-behavioural therapists or a psychologist (or psychiatrist) may also be able to provide practical coping methods that will help the person with a brain injury move past denial.


Depression is a complex health condition involving a person’s thinking, emotions, and behaviour. Depression is linked to grief. Many people with depression may feel sad much of the time, lose interest in their usual activities, withdraw from others, have a negative outlook on life, and experience changes in energy, sleep, and appetite. It’s important to understand the impact of depression, and how to support your friend or family member as they move through it. Depression may not only be psychological: brain injury can alter the brain’s structure, so depression can also be biological. The challenge of dealing with emotional and behavioural changes like depression require as much commitment in recovery as working on cognitive and motor skills.

When symptoms of depression continue for weeks or longer, mental health treatment may be necessary.


Impulse control/inhibition is the ability to think through actions and speech. When someone is experiencing disinhibition or impulsivity after a brain injury, they may:

  • Be easily irritated
  • Buy things they don’t need or can’t afford
  • Do risky, dangerous things
  • Have mood swings
  • Ignore social and safety rules
  • Make inappropriate remarks
  • Not be able to think things through
  • Speak impulsively

If your friend or family member is struggling with impulse control and disinhibition, there are ways to help them cope with these challenges.

Offer assistance
Impulse control includes elements of decision-making. They don’t have to make every decision on your own. You can offer to listen to their thought process out loud. You can also ask if they would like recommendations about how to act or respond to a situation. It’s important that you avoid being critical of their decision-making process. It can be difficult for people with brain injury to make decisions, and criticism can lead to frustration or anger. Instead, be constructive and encourage them.
Develop a process for decision-making
Having a decision-making process can help prevent impulsive, risky behaviour and ensure that the person considers all factors that go into the decision. This includes:

  • Their decision options
  • How their decision could affect others
  • How their decision could affect themselves
  • Write out the pros and cons of each option
  • Ask for advice
  • Share their decision with someone they trust before they act on it
Practice before social interactions
If the person has plans with other people and are worried about social interactions, p[practicing with them beforehand is a great way to build confidence.


Grief is an emotion that has a direct impact on how a person behaves. Someone experiencing grief after a brain injury may engage in risky behaviours or have angry/aggressive/emotional outbursts either alone or directed at others.

It’s normal to experience grief after a brain injury, but it’s important to understand how grief works.


Obsessiveness is when someone becomes ultra-focused on an object, a task, or even something someone said. They can’t think about anything else, may become incredibly stubborn, or do something over and over again. This can be made worse by anxiety or by injury to the parts of the brain that enables a person to shift the focus of their attention. It can make it harder to solve problems and maintain relationships.

Obsessiveness can be caused by a variety of things and can be managed with the right supports.

  • Identify what the trigger that causes obsessive behaviour (the antecedent), and eliminate the antecedent if possible
  • Encourage the person to take breaks, redirecting their attention is possible
  • Speak with a cognitive-behavioural therapist or psychiatrist or psychologist about how to cope with obsessive behaviour

Post-traumatic stress disorder (PTSD)

Post-traumatic stress disorder (PTSD) is a mental health disorder that occurs in people who have suffered a traumatic event. It’s common in individuals that have experienced assault, accident survivors, and people in the military. Behavioural symptoms of post-traumatic stress disorder include:

  • Anxiety
  • Increase in negative thoughts, feelings, and beliefs stemming from the trauma
  • Disassociation – losing touch with the present and feeling like you are experiencing the trauma again
  • Avoidance of certain situations that may recall (trigger) the trauma
  • Feeling on guard all the time
  • Sleep problems

Not every person who suffers a traumatic brain injury will have post-traumatic stress disorder. Additionally, not everyone with post-traumatic stress disorder will have had a brain injury. Only a licensed professional like a psychologist or psychiatrist can diagnose post-traumatic stress disorder.

For more information on post-traumatic stress disorder, visit our mental health and brain injury page

Self-image loss

Brain injuries not only change a person’s abilities; they affect identity (e.g., “Who am I now?”) and self-image because of the physical, cognitive, emotional and mental impacts. Someone with a brain injury may only focus on their limitations and fail to see their positive qualities. The emotions related to these changes can lead to behaviours such as withdrawal, avoidance or choosing not to take actions, and a lack of motivation to do anything – including work on rehabilitation and recovery.

It can be difficult to encourage someone who is experiencing challenges with their identity. Some ways you can help the person with their self-image include:

  • Celebrating their successes
  • Helping them get back to activities they enjoy, or finding new activities for them
  • Identifying the ways they have not changed (i.e. their kindness, their sense of humour, and other positive qualities)
  • Keeping a positivity journal: at the end of the day (or as they happen), the person should write down the good things that happened to them
  • Taking break. It’s normal to feel loss, and it’s important to let yourself process it

Sexually inappropriate behaviour

An uncommon behavioural effect of brain injury can be sexually inappropriate behaviour. This includes making inappropriate comments about themselves or someone else, inappropriate actions (such as touching), and exhibitionism, which is the act of displaying genitals in public places or to people without their consent. This behaviour can also include masturbation at inappropriate times or in inappropriate places.

It’s difficult for people with a brain injury to recognize that they are being sexually inappropriate. They may think their behaviour is normal. It’s important to work with a healthcare professional and help the person with a brain injury understand what is appropriate. Examples of how you can help them with this include:

  • Writing down what’s appropriate to say or do in social situations
  • Setting clear boundaries of where masturbation is acceptable (in the bedroom, with the door closed)

If the person has questions about sexual behaviour or sexual health, these should be shared with you or a healthcare professional. It’s important to have open, honest discussions about what they are feeling/experiencing.

Social dysfunction

Socializing after a brain injury can be difficult due to several factors, including how the person with a brain injury behaves. It’s common for people living with acquired brain injury to:

  • Have trouble keeping up in group conversations
  • Lack awareness regarding how others feel emotionally
  • Make inappropriate comments
  • Misinterpret social cues such as facial expressions
  • Mistake sarcasm for literal statements
  • Show aggression and frustration

Trouble socializing can lead to social isolation, anxiety and depression. Socialization is incredibly important for mental health, so it’s important to understand what is involved in being social after a brain injury and how you can help them.

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