Understanding Behavioural Impairment

  • Introduction
  • Causes
  • Loss of Self-Awareness and Behavioural Changes
  • Understanding
  • The Effects
  • Perspectives
  • Impulsivity
  • Obsessive Behaviour
  • Irritability and Aggression
  • Disinhibition – Lack of Restraint
  • References


The telling signs of behavioural and emotional outcomes following a brain injury often overlap.

It can be difficult for you to understand what is causing a certain behaviour or action because often, many things are happening all at once.

Things often erupt far too quickly for you to be able to be completely aware of the cause. Also, you may get past the incident so quickly that it soon passes from memory, leaving you with few clues to work out exactly what just happened.

Depending on how much self-awareness you have retained, you may remember more details from before, during, and after an event. You might feel very surprised that things are happening to you that would not occur normally, and will probably recognise thinking, ‘this just isn’t like me!’ 

Behavioural changes following a brain can happen to anyone because they arise from changes in thinking and executive skills. These differences are caused by lesions in the frontal cortex and are not due to changes in personality. 

You are struggling with deficits in your brain which alter the way you can manage and control your behaviour.

There are many interventions that help by addressing triggers and negative beliefs, which are often part of the root cause of changes in behaviour. 

You can also learn to work with your family and friends to use different strategies that will help your brain remaster the skills you had before. 

By learning more about the outcomes following a brain injury, and what causes them, families and friends can provide a lot of support and understanding. 

Causes of behavioural changes

Caused by many factors, behavioural changes following a brain injury begin with the primary physical damage to the brain caused by tearing, shearing, and any resulting cell death.  

This physical damage interferes with the ways your brain would usually spontaneously manage events in line with what it knows your preferences are. Over time pre-injury, you will have learned which aspects of your behaviour match and suit your preferred view of yourself, and your brain learns what these are so that you don’t have to stop and think every time you react or respond to any incoming situation. 

Metacognition is the thinking skill which usually helps you monitor what you are doing, and how you are feeling, as it is happening. We are usually aware of this as the ‘thinking voice,’ or inner narrator that ‘chats’ to us about what we are doing as we are doing it. This thinking skill is often lost after a brain injury – but – you can and will get it back if you set goals, and do everything you can to support your brain through its’ recovery.

Knowing it is your brain that is injured, not ‘who you are,’ permits the realisation that the are still the captain of your ship, and the further you get along your recovery path, the more you will feel in control of what is happening within, and around you. 

The more time you spend teaching your brain what you want and what your preferences are, the more you will feel like your old familiar self. 

This process takes time, especially for those who have a loss of self-awareness. As you move through the time ahead of you, it is possible to notice the gradual improvements you are making.

It feels somewhat like ‘coming home’ again or is often described as feeling as though you are growing up all over again. The more brain has opportunities to relearn what you want from it, the more it will get used to what it can safely do for you. Any areas of ambiguity will be ignored by the brain until it is assured that what it thinks is in line with what you want. 

So, even if you don’t feel like the captain of your ship, you have to practice behaving as though you are as early on as you possibly can. 

A great way to do this is to talk out loud to yourself and tell your brain what it did well, congratulate it, say, ‘well done brain – you did good!’ and pat yourself on the back to reinforce your pleasure at whatever it was your brain did well.

Conversely, you can also let your brain know, ‘brain, you can learn from this error and do better next time.’

There are more suggestions of things you can do to help yourself get you thinking back in self-regulated learning.

Other things that help with changed behaviour if you feel too swamped to manage on your own are:

  • CBT – Cognitive Behavioural Therapy
  • PBS – Positive Behaviour Support

A neuropsychologist will be able to you, perhaps directly – depending on who you see, or at least to guide you towards treatments and therapies that will help.

Loss of self-awareness and behavioural changes

Reduced or loss of self-awareness can interfere with how your brain feeds back comparative information to you that would let you know you are behaving differently.

When these functions are lost, you can feel as though everything you do is normal and justified – without adding the layers of justification to make this happen. Without metacognition, your brain thinks what is happening to you matches who ‘you’ feel ‘you’ are.

We know that the secondary outcomes, such as inflammation, also add to these challenges. As soon as it is known to be safe to address the biochemical cascade, currently believed to be at two years post-injury, there are supplements that help by improving the brain environment and consequently your thinking and understanding will begin to improve.  There are also many alternative holistic treatments such as acupuncture that can support healing.

It is important to bear in mind that some changes may be an exaggeration of previous your personality traits. If you were sensitive to certain triggers pre-injury, these are likely to become overblown. You will need to address these at some point and you will probably benefit from the guidance of a neuropsychologist or cognitive behavioural therapist. 

There are strategies you can use to help you relearn to pause and control outbursts. These are often best done with the support of your family and friends so they can help reinforce your goals and strategies.

For example, either you or they can do simple things like change the topic or redirect through distraction. If you all agree this is the best way to go, then they can safely remind you this is what you wanted. 

For families and friends it is really important to be both patient and sensitive towards people as it is possible that dealing with a huge array of changes and problems could cause mental health issues.

It can also help if families and friends learn to react to the situation and not to your behaviour. This is a practical approach and helps your brain understand that what it did was not appropriate of acceptable. Work this out with the people who love you and let them know it is okay to ignore you – the last thing you want or need are for responses to reinforce the negative behaviours you are trying to learn to master.

Whatever you decide with your family try and keep in mind that the choices you are all making together are aimed at improving everyone’s quality of life.

New science tells us that the gut can also affect behaviour, and, given that the chemical reactions of the brain to injury can cause adrenal fatigue, hormonal imbalance, changes to gut flora, stomach acids, and the workings of other vital organs, we need to view the body as a whole system and look beyond just the cellular brain.

What you eat and drink will either make things harder for you to get control back, or will support you. Think about which you prefer, make a nutritional plan, and stick to it.

Try to remember that changes can be overcome and do get better. Most people who struggle with behavioural changes notice they improve over time.


Many behaviours ‘just happen’ to you following a brain injury and come without conscious awareness of intention and often without preceding contemplation or thought. Just as PTSD can ‘fire’ without control, so too can behaviour.

There are a lot of things to take into account, such as possible pre-injury factors, upsets caused by the trauma itself, and even psychological issues that may need addressing and may exacerbate certain behaviours.

For example, if you had know triggers before, such as reacting strongly every time someone undermined you and hit your ‘lack of self-worth’ button, then you will likely react to a wider range of potential grievances. 

Some changes may seem completely out-of-character to you and often family and friends will attribute these to the effects of the trauma, which sometimes means the real cause may be missed or misunderstood.

Misunderstandings can very easily and quickly lead to frustration and anger because you are struggling to express yourself clearly in the hope you will be understood.

Differences in behaviour don’t automatically mean that the core personality has changed and that you will never be the same again. Your personality is intact – it is the changes and damage in your brain that are causing the behavioural extremes you are experiencing.

Recovering your sense of self can take time. Very often, especially when self-awareness is retained, the confusion and fear caused by outbursts are significantly distressing.

Behavioural changes can be extremely difficult to understand, and for families and loved ones to adapt to.

Because the brain is constantly rewiring following injury, there is a good chance that control will be regained. By thinking about what you want to do to address your behavioural changes you can work out a plan of action and focus on it.

In cases of very severe injury, it may be necessary to use medications to control behaviour, especially aggression and sexual changes.

With the guidance of a functional neurological specialist, it may be possible to use natural substances and diet to help you take back control instead of using prescribed medication.

Whatever you do, avoid all alcohol and drugs. Your brain environment is already inflamed and drugs and alcohol will only cause more damage and make things worse. You don’t need to ‘drown out’ what you are going through – you need to address it!

Behavioural changes can also occur after mild or moderate brain injuries.

The effects of behavioural changes

The ‘how’ of how we individually think has a huge part to play in how we feel about ourselves and our ability to maintain a unique integrity following trauma, so if our ‘thinking’ isn’t working very well, then how we see ourselves can be affected.
If you have negative views of yourself or of the changes you have been and are going through, these impressions will affect your behaviour. Nothing is ‘separate’ in the brain – all thoughts are connected.
Your sense of self is based on many things, including your beliefs, habits, and experiential memories.
Depending on your levels of self-awareness and self-insight, you may have intellectual knowledge that you were angry, for example, but may have no realisation about why. Alternatively, you might be oblivious to your own behaviour and feel all is well with the world and you have nothing to worry about.
A loss of self-awareness can truly leave us in a place of blissful ignorance and this is especially important for your family to understand if they think you are in denial.
If you have memory problems, outbursts might be quickly forgotten. 
It is vital that you feel understood and supported, and often, especially where there is a lack of medical treatment and understanding, family and friends find that they take on the role of caregiver and become the source of praise and feedback. This role is often difficult, rife with pit holes, and can cause stress and disharmony in relationships.

Working out a strategy together can help alleviate and overcome these problems.

It is important to treat the behavioural outcomes as individual events because letting them amass, can lead to erroneous assumptions about the cause.

Behavioural changes can bring another range of effects beyond the immediate challenges, such as becoming more aggressive or emotional.


Each of us can see changes in behaviour in very different ways.
For example, someone may struggle to maintain their social activities, and this may be viewed as an inability to ‘get over’ their trauma. It may not be this – either entirely or at all; it may be due to difficulties with communication or mental fatigue, for example. Many people find that they can’t focus or follow a conversation and so isolate themselves to avoid feeling even worse. This is why it is important to resist judgement.

People can also find it really difficult to be aware of or notice behavioural changes, which will impact their ability to both understand the changes and describe them.

Those living with outcomes may appear to be less flexible, obsessive or seem to have a complete change in attitude. Someone who was previously self-responsible may now seem to be more prone to a victim mentality, and someone who was conscientious may now seem less motivated or willing to help themselves.

There will be very real structural and chemical reasons for these changes, which are the preferred understanding, rather than the label that is generally given – change in personality. The personality has not changed – the behaviour has.

Believing that it is a change in personality can distance some people from dealing with their own levels of understanding and expectations. It is often seen as an unhelpful way to think because it enables people to dismiss what is going on around them, and to avoid taking responsibility.

All of these behaviours can cause worry, and very often it is the families and friends who are most concerned.

It is possible for the person living with the outcomes of brain injury to be oblivious to the changes others see. They may only become aware of behaviour if it is pointed out to them, or after a period of reflection about their confusion.

Insights gained may quickly be forgotten and in this respect, recovery can be very stop-and-start.

Knowing what to expect and understanding why things are happening can really help in our approaches to dealing with outcomes. It may be that everyone needs to adjust and be more aware of their expectations.


Cognitive impairments may cause you to speak or act before you have had a chance to make any considerations – especially about consequences.

Impulsivity is a fair indicator of the instability that is happening inside the injured brain.

Examples of impulsivity are: spending more money than can be afforded, saying things or making remarks without thinking about how this could upset someone, or, as commonly happens, agreeing to or offering to carry out a task without considering if you will be able to either do it, or complete it.

The willing attitude is still there – it just hasn’t been updated to understand the range of deficits that make many things much harder.

It is really difficult to be able to see a bigger picture, which is why consequences fail to be considered. It can be that there simply isn’t enough space in conscious thinking abilities to stretch further than a moment. 

Feeling impulsive?

It might pay you to try and teach yourself to pause when you feel an urgent need or impulse coming on.

A good tactic to employ would be to:

  • pause
  • write down what the impulse is
  • distract yourself with another activity
  • revisit what you wrote down only when you have a friend or family member with you so that they can offer their objectivity
  • if their feedback doesn’t make sense to you, or hasn’t helped you overcome your impulse, do the wise thing – sleep on it!

Impulses are driven by the brain thinking you have to have something or be somewhere right now. You don’t; teach yourself to take back control by pausing and listening to the feedback from the people close to you.

Obsessive behaviour

Brain injury can change the way you approach problems without you being consciously aware this is happening.
Sponsoring thoughts, ideas and impulses will feel normal to you – so no clues for you there!
It is more likely you will become obsessed with certain life issues, for example, trying to work out solutions to a problem for yourself or about someone else in a self-absorbed kind of way, than you will suddenly get OCD – obsessive compulsive disorder where you become finicky about details.
You might recognise that you have become fixated on one topic and then struggle letting it go, which can lead to perseverance which in turn, can also attribute to problems with switching from one subject to another.

Perseverance is a common outcome and may stem from a deep desire to be understood, meaning that you try to cover every angle possible and shares it all ‘out loud’ instead of being able to summarise.

You may have noticed that you have become obsessed with safety issues, so maybe you regularly check your money or that the house is locked. Most of the time, these behaviours are driven by the fear that something will be missed, lost or forgotten, and you are constantly rechecking things to make sure you have carried out your responsibilities.

You might also find that you insist on certain routines and doing things a certain way. This is mostly driven by the fear of forgetting how to do something after you have learned it again.

When relearning strategies and coping mechanisms, you might be obsessive about repetition because you understand this is important to regaining lost skills.

While this can make you appear far less flexible to your family and friends, in reality, you need support and the room to stick to these learned routines until such time as the new neural pathways are strong enough for you to have formed habits.

The more people recover the less obsessive they are.

Irritability and aggression

Many people struggle with increased irritability and we can all empathise with how horrible this feels.

Other people might think you appear to be impatient, however this is generally caused when you are struggling to keep focused, rather than being about your attitude.

You might find you are less tolerant of others’ mistakes, and again, this isn’t down to you having made judgements or assumptions about someone but is usually caused by a fear of your attention capacity being overloaded. You will instinctively know that when the thinking space in your head gets full up that you will be more likely to forget other important things you are trying to keep in mind and remember.

Irritation can also occur as the result of disruptions or interference. Background noise can also be a big problem as it makes it much more difficult for you to maintain your attention and concentration.

Disinhibition – lack of restraint

Disinhibition is a loss of control over behaviour.
This is caused by many complex factors resulting in spontaneous behaviours that are often socially inappropriate. The control mechanisms of the executive systems break down and fail to mediate behaviour before it is displayed. This again is really horrible to live with, and many people struggle with embarrassment and shame.

Your family and friends might wonder why you keep repeating the same ‘mistakes,’ but this isn’t about putting your foot in it occasionally. It is about having to live with an impairment that you cannot control, and struggle to learn about because of memory issues and other cognitive impairments.

You may or may not be conscious of making tactless remarks, or of giving too much personal information about yourself, or others. You might also laugh at the wrong things at the wrong times.

There are therapies which can help you become more aware of your behavioural problems, or even the underlying negative beliefs that you might not know are there, but will be driving this behaviour. 

.These are awful events to experience, especially when they pertain to making inappropriate sexual remarks or advances. Sometimes overwhelming feelings of frustration with being unable to control these actions can lead to temper outbursts or even aggression.

And finally:

  • Specialist services are available to help with managing behavioural issues. Speak to your doctor and ask for a referral to a neuropsychologist
  • All of these changes and more are looked at in more detail in the articles and posts section of the site. These are regularly uploaded to the Global Brain Injury Awareness page on Facebook. To receive notifications, all you need to do is like or follow the page
  • Always discuss strategies and ideas that may help with your family, friends and with professionals
  • Keep hope and remember that neuroplasticity means this is not forever
  • Talk to other people, learn from mistakes and recognise vulnerability
  • For families and friends – At some level, people will be aware that their behaviour is inappropriate. It isn’t always necessary to constantly correct people, try and judge when it is okay to ignore or overlook behaviour
  • For families and friends – think about. ‘what is this behaviour trying to communicate?’
  • For families and friends – ask what the problem is rather than taking it personally and reacting yourself


PubMed – Starkstein SE, Robinson RG. Mechanism of disinhibition after brain lesions. J Nerv Ment Dis. 1997 Feb;185(2):108-14. doi: 10.1097/00005053-199702000-00007. PMID: 9048703.