Personality Changes

Personality changes following a TBI

Following a TBI people may have difficulty with their social and emotional behaviour. Patients who have suffered a severe TBI may have trouble recognising facial expression and social cues, leading to poor social judgement and loss of inhibition.1

People who have suffered a mild to moderate TBI may have personality changes which are more related to feeling that they have lost some of their sense of self.2 They may feel a sense of grief for the person they were, and anger that this has happened to them.

Signs of personality change

Following a TBI, a person may suffer from a number of changes in social and emotional behaviour. These changes may include:

  • Indifference / the inability to empathise
  • Emotional lability
  • Poor social judgement / loss of inhibition
  • Aggression
  • Loss of patience
  • Self-absorption


Impulsive aggression is verbal or physical aggression that is the result of a patient no longer being able to self-regulate their emotions. Impulsive regression is when a patient is triggered by something relatively minor, responding with aggression which is out of proportion to the initial act.These symptoms may begin as irritability and agitation directly following a TBI, then progressing to impulsive aggression.

Emotional lability

Emotional lability is a symptom of TBI which affects a patient’s personality by causing them to react hysterically – for example they may laugh or cry uncontrollably in situations where it isn’t appropriate. This usually doesn’t reflect how the patient is actually feeling, and can be triggered by a trivial occurence.4  The person’s brain will usually respond in this way when it is overstimulated and is unable to process everything that is happening around them.

Indifference / the inability to empathise

A lack of empathy can be observed following a TBI. There is no link to a lack of empathy and the severity of the TBI suffered, however lack of empathy and indifference is noted to affect males more than females.5

Poor social judgement / loss of inhibition

Poor social judgement and loss of inhibitions can be in seen in either physical or verbal actions. A loss of physical inhibition may include acting impulsively and making intimate advances. Verbal behaviour may include offensive or insensitive remarks, the use of profanity and failure to take note of social cues. This may include interrupting, not waiting for their turn to talk, and becoming self-absorbed within a conversation.6

Ask for help

Personality changes following TBI can be distressing to both the person with TBI and their carers and loved ones. Your GP may be able to offer advice and / or a referral to a neuropsychologist who may be able to assist with treatment strategies to moderate behaviour.

Disclaimer: This website does not provide medical advice for individuals. If you or a loved one are experiencing personality changes following a TBI it’s important to contact your medical professional for individual advice.


  1. Maarten Milders, Sandra Fuchs & John R. Crawford (2003) Neuropsychological Impairments and Changes in Emotional and Social Behaviour Following Severe Traumatic Brain Injury, Journal of Clinical and Experimental Neuropsychology, 25:2,157-172, DOI: 1076/jcen.
  2. Persinger MA. Personality Changes following Brain Injury as a Grief Response to the Loss of Sense of Self: Phenomenological Themes as Indices of Local Lability and Neurocognitive Structuring as Psychotherapy. Psychological Reports. 1993;72(3_suppl):1059-1068. DOI :2466/pr0.1993.72.3c.1059
  3. Rodger Ll Wood & Rhys H. Thomas (2013) Impulsive and episodic disorders of aggressive behaviour following traumatic brain injury, Brain Injury, 27:3,253-261, DOI: 3109/02699052.2012.743181
  4. Hurley RA, Taber KH: Emotional disturbances following traumatic brain injury. Curr Treat Options Neurol 2002; 4:59–75Crossref, MedlineGoogle Scholar
  5. WOOD, R., & WILLIAMS, C.(2008). Inability to empathize following traumatic brain injury. Journal of the International Neuropsychological Society, 14(2), 289-296. DOI:10.1017/S1355617708080326
  6. Osborne-Crowley, Katherine & Mcdonald, Skye. (2016). A review of social disinhibition after traumatic brain injury. Journal of Neuropsychology. 12. 10.1111/jnp.12113.