Personality Change

Medically Reviewed By William C. Lloyd III, MD, FACS

What is personality change?

Personality change refers to a shift in the way you think, act or feel. It may be noticeable only to you, or it may be evident to people close to you.

Gradual personality changes can be normal as you age. It is also normal for you to have changing behaviors or feelings based on your mood, but these changes are temporary and can usually be attributed to a specific event. A sudden, undesired or uncontrollable change in your personality may be the sign of a serious condition.

Several mental illnesses can lead to personality changes. These include anxiety disorders, borderline personality disorder, dementia, and schizophrenia. In the case of mental illness, personality changes may be the result of an interplay of factors, including heredity, environment and stress. These types of changes typically emerge before adolescence. Most mental illnesses are thought to result from imbalances in brain chemicals (neurotransmitters) and are treated with medication and psychotherapy.

Sudden changes in personality can also result from brain damage or infection. Possible causes of brain damage include injury, stroke, infection and inflammation, among others.

Seek immediate medical care (call 911) for symptoms of acute brain damage, including confusion or loss of consciousness for even a brief moment, garbled or slurred speech or inability to speak, severe headache, and sudden change in vision, loss of vision, sudden weakness or numbness on one side of the body, or eye pain. It is also advisable to seek immediate medical care (call 911) for psychotic symptoms such as seeing or hearing things that are not there (hallucinations) or behavior that endangers yourself or others, including threatening, irrational or suicidal behavior.

If your personality change causes you concern, seek prompt medical care.

What other symptoms might occur with personality change?

Personality change may accompany other symptoms, which vary depending on the underlying disease, disorder or condition. Symptoms that frequently affect the brain may also involve other body systems.

Mental illness symptoms that may occur along with personality change

Personality change may accompany other symptoms that result from an underlying mental illness including:

  • Anxiety

  • Depression

  • Detachment

  • Engaging in harmful, hedonistic behaviors (binging)

  • Hostility

  • Recurrent, unwanted thoughts (obsessions)

  • Repeated, uncontrollable actions (compulsions)

  • Social isolation

  • Thoughts not based in reality (delusions)

  • Unreal sensations (hallucinations)

  • Unstable mood

  • Unwanted thoughts or feelings

Other symptoms that may occur along with personality change

Personality change may also accompany symptoms related to other conditions including:

Serious symptoms that might indicate a life-threatening condition

In some cases, personality change may be a symptom of a life-threatening condition that should be immediately evaluated in an emergency setting. Seek immedi ate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:

  • Abnormal pupil size or nonreactivity to light

  • Being a danger to yourself or others, including threatening, irrational or suicidal behavior

  • Confusion or loss of consciousness for even a brief moment

  • Garbled or slurred speech or inability to speak

  • High fever (higher than 101 degrees Fahrenheit)

  • Paralysis or inability to move a body part

  • Sudden weakness or numbness on one side of the body

  • Worst headache of your life

What causes personality change?

Sometimes, personality change is a normal part of development. It can also be the result of deliberate effort or therapy. Sometimes, however, personality change is unexpected, unwanted, or not controlled. In these cases, it may be related to an underlying mental illness or damage to the brain.

Mental illness causes of personality change

Personality change may be caused by many different mental illnesses including:

Other causes of personality change

Personality change can also be caused by other conditions or events including:

  • Brain damage or tumor

  • Certain medications

  • Deliberate effort

  • Drug or alcohol abuse

  • Exposure to toxic substances or poisons

  • Head injury

  • Infection

  • Major life changes

  • Stress

  • Surgery

Serious or life-threatening causes of personality change

In some cases, personality change may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

    Questions for diagnosing the cause of personality change

    To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your personality change including:

    • When did you first notice your personality change?

    • Do you have any other symptoms?

    • Have you been ill recently?

    • Have you had a recent injury?

    • Have you experienced any major life events recently?

    • Do you have any diagnosed mental illnesses?

    • Do you have a family history of mental illness?

    • What medications are you taking?

    What are the potential complications of personality change?

    Personality change can be normal, and in some cases may even be the positive result of your deliberate effort or the result of therapy. In other cases, however, personality change is unwanted, unexpected, or uncontrollable. In these situations, personality change may be the result of brain damage or infection, or a mental disorder.

    Because spontaneous personality change can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

    • Absenteeism from work or school

    • Alcohol or drug abuse

    • Depression

    • Development of mental illness

    • Inability to perform daily activities

    • Loss of employment

    • Loss of relationships

    • Paralysis

    • Social isolation

    • Spread of infection

    • Tumor progression

    Was this helpful?
    176
    1. Borderline personality disorder. National Institute of Mental Health. http://www.nimh.nih.gov/health/topics/borderline-personality-disorder/index.shtml.
    2. Personality disorders. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001935/
    3. Lieb K, Zanarini MC, Schmahl C, et al. Borderline personality disorder. Lancet 2004; 364:453.
    Medical Reviewer: William C. Lloyd III, MD, FACS
    Last Review Date: 2021 Jan 7
    View All Mental Health and Behavior Articles
    THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.