Why Has My Sister's Personality Changed Since Her Traumatic Brain Injury?


My sister was in a car crash a couple of years ago. Since the wreck, her temperament has changed drastically. She is very snappy toward her children and doesn’t seem to get any pleasure out of life. We are all worried about her lack of visible emotion. Any suggestions on how we might help her?


Personality changes like your sisters are not uncommon following a traumatic brain injury. After all, how we think and process the world is so much of who we are. Temperament is essentially the way our brain interprets the world around us. With a brain injury, the mechanisms we use to filter and understand information are disrupted. Personality changes can come from two sources following a brain injury:

  • specific changes in how the brain experiences, understands, modulates, and expresses emotion
  • emotional reactions to the changes brought about by the brain injury

Brain injury can affect connections that go from the cerebral cortex (the thinking part of the brain) to the limbic system (a series of inner brain structures that control and modulate emotion). These connections allow us to evaluate our emotional reactions, determine how important or minor events are, and decide on a response that matches the demands of the situation. When these connections are impaired, our emotional reactions are different from what they were prior to the injury, and are not always in tune with the situation at hand.

In addition to this, a brain injury can be emotionally traumatic. People respond with anxiety, frustration, anger, sadness, and depression to their changed capabilities and life circumstances. It’s normal for people to mourn the life they once had and try to find ways to cope with their new life and personality. These responses are affected by the potentially impaired connections described above, and may result in emotional extremes.

It is not unusual for the person with a brain injury and/or his or her family to need some counseling or therapy to understand this new identity, personality, and emotional reaction style. The person with TBI, like your sister, may work on learning strategies to better express emotions, avoid those situations likely to be particularly frustrating, read signs of emotional distress, and react in a calmer manner to emotionally charged situations. You can help by learning strategies to de-escalate your sister’s emotional outbursts, redirect her anger and frustration, understand the meaning behind a particular emotion (or lack thereof), and help create a calming environment for all concerned. A therapist or counselor may also recommend exploring the option of medication, depending on the nature and severity of your sister’s personality challenges.


Posted on BrainLine July 7, 2010. Reviewed July 26, 2018.

Comments (33)

I was hit in my car by another vehicle that ran a red light May 2018. The airbags did not deploy despite two impacts in the crash and totaling my car. My head hit the drivers window. My adult daughter was with me and she was “obviously” hurt, my entire focus was on her. My physical injuries seemed relatively minor, so I did not seek medical attention until the next morning.

I have always been a “mind over matter” person, so I minimized everything except the anxiety created by the wreck. I was first diagnosed with PTSD through counseling I sought due to the almost debilitating anxiety I was dealing with. As things were sorted out through symptoms and tests, it was determined I had suffered a TBI (concussion) when my head hit the window.

Seven months post-accident, the anxiety has lessened but my personality has changed. I had been a very successful entrepreneur building a company from the ground up to over 700 independent contractors. About a year before the accident, I had developed a second business and was excitedly building both. Everything I have ever done, I always wanted to be my best and to lead. I have always been high energy and a risk taker. Now, I just want to be in the background. My favorite place to be is now at home rather than going 100 mph. I have withdrawn as much as I can and am fearful in situations that never would have scared me before. Sequential activities that I have done many times prior to the TBI I can still do. If one new item is added to the sequential activity, the task becomes overwhelming. My family has been very understanding and supportive but when asked have shared how much my personality has changed.

My counselor seems to think all this is from PTSD. The Neurologist has me progressing through Cognitive Remediation which is helping with the Executive Functioning aspects. My ability to initiate business activity has been dramatically reduced. Because my income is pivotal for our family, I have begun to look for jobs as an employee to help bridge the income gap.

I am beginning to wonder if this “new me” is my new normal. I feel like there is a gap in my care but don’t know what it is or how to find it.

I would put a great deal of this to being in slow-motion shock/trauma, on a psychological as well as a physical level.

It is important to relax, and gain confidence without feeling under pressure or anxious.

I am 28 years old and suffered a brain injury from an amusement park ride almost a year ago. though all imaging and other medical evaluations have been “normal” i have still not recovered, am unable to work, and have a long list of debilitating physical symptoms. however the most difficult things by far have been the changes to my personality, my sense of self, and my emotional brain.

though i recognized early on a tendency to severely overreact to certain things or misperceive a certain situation or someone’s words/behavior, it’s taken me this long (a year) to start to recognize the ways this has really affected/changed my overall personality, disposition, and demeanor. i often feel like a stranger to myself and cannot trust my own emotional responses or even my own train of thought much of the time. i have major panic attacks on a regular basis, sometimes daily.

one thing i’ve noticed that seems consistent with what others have said about themselves after this kind of injury/event: i seem not to have a filter anymore, no awareness of my behavior, my demeanor, my words. i flippantly say things that are offensive or rude, can talk for hours as if on autopilot with no awareness of what i’m saying or how long i’ve been speaking (NOT my old personality at all), cannot easily hide or disguise my mood, and am prone to somewhat delusional thinking.

i stutter. i often cannot comprehend humor and need things that are “funny” to be explained to me. i do still have a sense of humor, it is just different than it was before. i feel plagued by intrusive thoughts and frequently have an overwhelming and urgent desire to harm myself though i do my best to refrain.

the people i am close to have a hard time dealing with my somewhat erratic behavior but at the same do not take me seriously.

my very best wishes and love to everyone out there who is suffering through a recovery from brain trauma or post-concussion syndrome. these are my recommendations:

sleep as much as you can if you are able.
eat well when you are able and always stay hydrated.
try to find joy in little things, and forgive yourself for what you are no longer able to do.
spend time outside, nature is healing and grounding.
meditate, find reasons to have gratitude, and keep a journal if you can manage.
it helps to maintain a running log on reality, to account for the passing of time, to process thoughts and feelings, and try to have some peace.

your essence is still within you, even if you can no longer convey it to others.

I think it's real cool that u shared your true feelings with people to read about how you struggle day to day and how sometimes the people in your life can't understand you. I can't Imagine how hard and frustrating it would be to walk in your shoes and you to not be the same person. My best friend he is funny and cute and means to to everyone he meets but I'll tell you my goodness he's a firecracker and I have no idea how I'm suppose to continue to deal with our weird friendship because it really does put so much stress on me. There's no question I adore him and couldn't just leave him hanging, I may be the only I hope normal he has in his world. He was in a crazy car crash and suffered a catostpic head injury and all kinds. I didn't know him before I met him 8 years after. But I don't believe he used to be the way he was, the words, choices and things he does is beyond my understanding. Do you believe that your a different person and how did you discover that? And it is hard for you to keep relationships? And what suggestions would you have for me to better understand someone who has had or is going through a TBI, I really just need a better understanding before I always jump to harsh comments backs or lose paitence. I'm just tried maybe, but I'm trying to understand what its like for him everyday. I saw this comment and thought I would try and reach out to you.

I also suffer from a lack of filter. I try to pause to word things appropriately then completely forget what I intended to say to begin with. I ramble nonsensical statements and judgemental opinions constantly not because I am an A hole but I have no control of what I am saying. However I later realize what I am saying later on was absolutely hilarious. As well as incredibly offensive towards the other party and even to my own self. And this is why I have no friends. Amen. Peace be with the force within you. Ackuna matattta.

My friend got into an accident on the 21st of May 2018. He had a neck and brain skull fracture. It's been three months now and I have seen some personality changes in him. He talks more than he usually did. What could happen after that? Can any of you explain it? How should I react to his speech? Should I go with the flow?

my best guess would be to take it seriously. it does make sense, right?

My husband and I were in a horrible car accident 4 years ago, we were stopped for a school bus- and a semi came up behind us and never touched his breaks until after the crash. We are survivors, It’s taken me 4 years to realize that I have some severe personality changes! I guess when you finally realize that Nothing brings joy to you and you can’t remember the last time you actually smiled, let alone laughed! I have had so many things that I have let just slip by. Because I can’t focus on anything long term- I use to be a take charge and help,do plan and get things done kind of person! Now life is just passing me by and I didn’t realize how much I’ve missed, let alone how much disappointment I’ve brought to my children! Beacause my daughter have gotten married! I DID NOTHING To HELP HER PLAN, PREPARE For, Beacause I Am just numb.
I just realize that I have a lot of relationships that have been hindered these last 4 years! They hell- I don’t know what’s going on, only that I’m NOT WHO I USED TO BE! That so much time has gone by - that people think you are just a B.

My husband suffered his 4th concussion/ tbi in a car wreck 3 years ago. This car wreck was very minor compared to one he had 13 years ago that left him in a coma for 2 days. It’s strange how this wreck caused more damage then the coma crash. I would say it’s true that once the brain is damaged it’s far easier to damage again. His personality change reminds me of when my sister started showing signs of psychosis. Small things that are hard to pin point but are just off. The quickened temper, depression and frustration haven’t really dissapated although his creativity is starting to re emerge. He used to be an insomniac but now can’t ever get quite enough sleep. I understand these are all connected and feed off each other, my man is still here and alive albeit slightly tilted.

My ex-husband suffered from a bad concussion, and shortly thereafter, began to behave in very uncharacteristic ways. This was about 16 years ago, in 2001 or 2002) so there wasn't as much information about this topic as there is now. While reading this and other similar articles, I have had an epiphany!

My ex ended up cheating on me, and behaving very strangely in the last year or so of our marriage (at the time I attributed his behavior to extreme stress). But then, even after the divorce, and at time when his life seemed to have settled down and be going well, he continued with angry outbursts, at both me and our children. Very unreasonable and very unlike him. At one point, he came to me in person and apologized for his angry. He was much nicer for a time, but unfortunately, the angry, unreasonable personality returned. I have said that ever since our divorce (that he wanted so he could marry his awful girlfriend - which, by the way ended in divorce after a few short years) he is not the same man I married. Our long time friends have noticed it as well.

I have lamented many times - "what happened to him??" I think I have my answer. His severe concussion - now known as a TBI - had an affect on his brain and personality. So sad - because I am now convinced that but for his undiagnosed TBI, our family would still be together and my children would understand why their father has, at times, treated them so callously.

The good news is, I can educated my now adult children on the affects of TBI's and explain that a brain injury is what caused their father's erratic behavior.

I was hit with a baseball bat when I was 9. I fell to the floor, bleeding from the side of my face. I was rushed to a hospital and got stitches, but I was never test for a concussion at all. But, I've noticed since, I've become extremely shy, I have troubles with extreme sadness or a lack of motivation as well as uncontrollable rage for very small things. I also have really broken sleep, and wake up often, have sleep paralysis, and night terrors. I hadn't even considered until now that I could possibly have a serious concussion and I should probably look into getting tested.

I was in a motorcycle accident almost two years ago. My back tire slid out from under me and I hit a median doing roughly 65-70.... I still have gaps in my memories, and have noticed a lot of behavioral changes in myself.... It even cost me my marriage.... I used to be slower to get frustrated and a more outgoing person, but now i spenx more time listening rather than talking. I used to write poetry, and now when i try its like a permanent writers block. I've also noticed more subtle changes... I used to love video games... I used to play them for hours at a time, bur now I'm just not interested.... Its been hard because friends i havent seen in years are always asking me why I'm quiet or why i dont want to play games with them anymore, and i dont know what to say to them... I feel guilt because i'm sobmuch quicker to anfer and a lot of times I snap at people before i even realize it... People I really care about, who dont deserve it.

Last year, I suffered TBI after a road traffic accident, I sustained a head injury and fractures. In my experience, the journey doesn't get easier fast and people I've spoken to that have had similar tell me that with patience and time, things do improve.

With time, support from friends, medical staff and willpower, I have found that I've learnt to adapt to the world around me and get through those uncomfortable and disorientating times.

I have experienced a personality shift. I question a lot more if I something is not clear to me. Some people are ok with this and others not so much. With time, I have had exposure to lots of different social situations, challenges and environments. I have learnt to create helpful strategies and shortcuts for myself.

These things have helped me:

I chart my daily activities at the beginning of the day in the form of a simple list. I tick stuff off as I go along.

With time as my memory has improved, I found drawing mind maps was helpful to help give myself an overview of my day/tasks.

I would recommend finding a local group/charity that runs support groups for people with brain injury, its helpful to meet others that have been through similar.

I found a local poetry group to join, this help me to unscramble words, spell again and express myself better on paper.

Don't isolate yourself, even if it means going on a short walk with a neighbour, family member or friend, fresh air will do you good.

if you can remember to say "thank you" to people that help you, it's nice to be appreciated, works both ways.

if you are having trouble expressing yourself in words, pause. Try to explain what you are having trouble with. Often family or friends want to help but may find your behaviour or words unclear or confusing.

Be patient with yourself. Do something relaxing for yourself daily, even if it is as simple as starting the day with a nice cup of coffee/tea, taking your dog for a walk or listening to calming music.

Thank you for your comment. My TBI is a result of a car accident over 40 years ago. At the time medical and social knowledge did not recognize the affects of TBI. I'm really having a hard time with a lot of issues about my personality and problems I've had over the years. I've not been very gentle or patient with myself. Your comments made me realize that is my starting point for self acceptance and this part of my journey. I had an MRI several months ago which showed the damage the injury caused. Ive been angry about so much and just wanted to go back and tell people please understand this is not mental illness it is a result of damage in my brain. I can't do that but I can be kinder to myself. Thank you

My husband was in a car accident three years ago and was in a coma for a while, he had bleeding and swelling to his brain with two abrasions to the side of his head and bruising to the brain stem. Three years later his personality is completely different and his stress tolerance is very low. He has anger outburst and its really starting to take a tremendous toll on our four children and marriage. Im hoping his doctor can proscribed him something to help manage his mood. I starting reading up on TBI and realized its common in most cases. I'm hoping something can help him.

I have the same situation with my husband. He was in a car accident 30 years ago and was in a coma for 13 days. We’ve been married for 25 years and I heave always felt that he was just erratic and explosive in his anger outburst. But it’s taking a toll on me and our five kids. He apologizes all the time and starts fresh but it is just so wearing and I feel so isolated because there is bitterness below all the arguing. Did you ever find a medication to help your husband? And what kind of doctor do you recommend seeing for a TBI that is the cause of irrational behavior?

I miss the fun loving, happy person I use to be. I'm trapped in this brain that is fearful of leaving my home, or afraid for my family. I haven't worked or gone out. I won't even go to the store. Thank goodness my husband and 12 year old understand me. I feel guilty about that. I alienated friends which makes me feel like no one cares. I tell my PCP my worries and he just puts me on another antidepressant. Thank you for listening.

Definitely get a new doctor and keep asking everone for any information on a good doctor who understands brain injuties. Keep looking for a group for people with similar problems and join it. Try desperately to stay off anti-depressants. Go to a good health food store and see if anyone there can recommend some good helpful supplements. They can work wonders.

I know how you feel. I am the same way. I do go to the store but only with a couple people who somewhat get it and only because I have to. I feel very alone. The doctors don't seem to understand. I don't understand. I've changed. I am not the person I use to be. Thank you so much for sharing. I now no I am not the only who feels this way and its that a little comfort.

How are you doing? I have lots of same challenges.

Can't cope

My son had a car accident at 20, traumatic brain injury, brain shear.  He lost his empathy, quickness in thinking and drinks heavily now at 32.  In some ways he seems the same but I feel like I lost my real son. I miss him a lot. He has a baby daughter and nice wife.  She only knew him after the accident. He speaks 2 languages.  The second language became dominant.  He can't remember much of his childhood. 

I had mine at around 18, sucks the moment you realise your personality has changed and will never return and you know you'll miss out on life's best things. I miss the way I used to react sharply , interact richly, and think deeply. I remember always laughing and making people laugh , I remember being highly intelligent and being a very effective communicator. I remember just getting things, and understanding new information. I remember being liked and envied by one or two because I had a personality that stood out. In many ways I am wiser now and understand people better. It don't think of it often, except for maybe when I'm with my brothers who are 8 and 10 years younger then me and now adults and I wonder how we would interact if that didn't happen. I've gotten used to a lot of people not talking to me properly, I sense those that judge me and sense those that don't. When meeting someone new theres always that moment that they realise , I've gotten used to that. But when I'm superficially reminded of the change is when someone says something jokey and I don't react quickly to build rapport, or when in a group of people having jokes and either I don't react quickly or lack the confidence to participate when the situation allows some of my old way of thinking to come through, as opposed to the new state which is mostly empty, or a negative type of energy.

Oh my gosh........ you are me. You have explained the changes in my life! I know how dejected and alone you feel, and I'm so sorry.

My daughter had a TBI and stoke from a accident in March 2014. Her personality has change drastically also her ability to cope with things. It's sad to me to think this will never heal or get better. It's so hard when I the care giver gets most of the aggression. She can't speak well it move her right arm. My heart aches for her and grieves for the girl she used to be, but I'm blessed she is still here.

I t~ boned a semi that pulled a u~ turn on I95 out of the southbound side. We made contact in lane one on the northbound side. He claimed he was just merging. Long storey short, it took 16 weeks to learn how to walk and talk. I had a jeep transmission in the back of my truck that catapulted over my cab, hit his sleeper, and fell through my windshield. I took the full force of it in my face and forehead. I was out going and fun.but after I lost all interest. My 8 month old son has missed out on who I was. He is 13 now and I am grateful that I am here but I'm not the same.

I was in a severe car accident in which I broke my neck, had a skull fracture and was scalped from the front of my head to the back. It required 700 stitches to close and I have never been the same since. I feel it really difficult to interact with people. I don't know how to speak to new people and groups. I previously had absolutely no issues in this area. I can be blunt and I have a short fuse. I feel high anxiety, can't stand certain noises or bright light and become angry very quickly. Extreme sleep disturbance. I know what's happening to me but can't control it. My kids and I suffer because of it. I wish I knew how to fix it.

I received my brain injury 14 years ago...I t-boned a car at an intersection..open head injury..I was unaware of the fact that the person I was had died in that accident. Experience everything in your article daily...but would like to share an example of the silent world you spoke of. It was a few months after my accident, I was to my neurologist earlier that day...and still could not effectively react physically to right and left, and not cleared to drive or return to work. A family member wanted to know when I was going back to work...."there was nothing wrong with me".....

I was t-boned by a semi-truck; a sudden quick speed as he didn't see my car stopped in front him in intersection to let pedestrians pass cross walk. I remember the sensation of a warm electric pulse move from my tors to my head. I had to slowly walk, move arms for about 6 months. I was 38 years young and still very physically active prior to! I cycled, swam and ran on daily basis. Now, 5 years later.after accident as I age, I do find the strange inability to engage in large group conversation, the inability to understand sarcasm, and at times the difficulty in getting my point across. At times it is frustrating, but I've learned to accept that I can't hide my feelings too well :( to be socially polite, and I think if you've had MTBI, TBI, in social situations maybe this is why it's difficult to contribute: for me, I definitely am aware I can candidly say things that can come across as offensive! Good luck and chin up all who have this. ... it's a very silent world thats kept to oneself. But do know, there are others who have this injury that feels the same way :-/

I had a mild head injury as an older child due to defective playground equipment that dropped a 4-6 lb bolt & chains on my head. Only lost consciousness temporarily, no fracture, just stitches for scalp laceration. But after that, my grades went down, lost powers of concentration. Can even mild head injures make long term effects?

I have the same question.

I know this comment is almost three years old, but since no one answered I will. Yes, no matter whether it's mild or serious, a head injury can have effects even medicine today can't explain. I think it's safe to say that your accident had some role to play in your grades and concentration problems. I hope things went well for you anyway after that.

Im a veteran, and was in an accident where my head was caught in a hatchway when I was aboard a naval ship back in 1975. My symtoms are very simular to those here, yet, why am I have such a problems with the Veterans Admin checkin this all out??None of this information was available back in 1975. What can be done to correct this??? Pat Bryan eagleone200@hotmail.com