When Someone's Personality Transforms, Pay Attention

Brain injury or disease can result in unfamiliar behaviors.

Posted Sep 06, 2018

ilolab/Shutterstock
Source: ilolab/Shutterstock

One of the most striking things that happened to me during my brief descent into insanity was that my personality changed.

The changes weren’t extreme. It’s not like I became a totally different person. And because my behavior morphed over a period of days and weeks, the changes were, at first, hard for my family to recognize.  

A normally loving mother, wife, and grandmother, I became irritable and angry at my husband, children, and grandsons. I snapped at them for the littlest things and criticized them relentlessly. Always strong-willed, I became impossible to deal with and couldn’t be convinced of anything I didn’t want to hear. I’m typically the one in the family calling many of the shots, but now I began to order everyone around. I also became obsessed with minor things—a late train, what I was eating for breakfast or lunch—but ignored the larger problems that loomed around us, including my own disease.

Initially my family thought I was acting strange because I was anxious about surviving cancer. But increasingly I turned into a monster whom they didn’t recognize. I became emotionally detached, unloving, and hyper-critical, which was exceptionally painful for them. Not only did they believe I was dying, but they were heartbroken that this coldhearted version would be their last memory of me. Many families of people with mental illness go through the same terrible experience. They feel like they’ve lost the person they love, even as that person remains alive.

It is often challenging for families and coworkers to recognize personality changes caused by mental illness, especially when they are exaggerations of normal personality traits. If a person was always frank and outspoken, a growing lack of social judgment may be construed as his typical bluntness rather than a sign of brain damage or disease. When an introvert becomes more withdrawn, family and friends may not realize she is exhibiting symptoms of Alzheimer’s disease.

Personality changes are very common in mental illness, especially when the frontal lobes are involved. People with frontal lobe damage—whether due to head trauma like the famous case of Phineas Gage; brain tumors, as with me; or a neurodegenerative disease such as Alzheimer’s—often undergo significant personality changes. In some cases, the changes are truly bizarre.

As its name suggests, the disease of frontotemporal dementia (FTD) involves the frontal and temporal lobes. FTD often results in extreme personality changes and inappropriate behaviors that can be hurtful and embarrassing for families. Some patients become sexually inappropriate, some spend enormous amounts of money without concern, some can’t stop eating. It’s as if their ids are running amok with no superego to override their impulses and desires. A progressive disease, FTD tends to strike people at a younger age than Alzheimer’s. Sixty percent of cases occur in people 45 to 64 years old, or middle age, so at first it may seem that the person is going through a mid-life crisis—until the disease’s inevitable progression makes it clear something more serious is happening.

I and my co-author, Elaine McArdle, hope that our book, The Neuroscientist Who Lost Her Mind: My Tale of Madness and Recovery, will shed more light on mental illness, including the fact that personality changes can signal that someone is suffering from a brain disease or injury. With that knowledge in hand, patients and their families and friends can seek professional medical assistance that might help alleviate suffering.