The unraveling of personality in MS patients and why is it so challenging to treat

I have run a busy multiple sclerosis (MS) neuropsychiatry clinic for more than 25 years. MS can affect a wide range of behaviours. Rates of depressive and anxiety disorders are high and there are numerous cognitive difficulties that are part of the disease. Many behavioural changes have been directly linked to the disease itself; evidence for this comes from structural and functional brain magnetic resonance imaging. There are also data showing that symptoms like sadness, hopelessness and anxiety arise as a consequence of being unable to adjust to the limitations that might come.

One of the most challenging clinical conditions that I see relates to a personality change. Medical professionals tend to overlook depression and focus instead on the physical disabilities that hinder daily life. Moreover, certain symptoms of depression, like fatigue and insomnia, can overlap with those of MS and are therefore easily missed.

One of my patients, a 46-year-old man with MS, has come to see me accompanied by his wife.  Multiple sclerosis has affected his ability to walk, but only slightly. He is a little unclear as to why he has the appointment. His wife, on the other hand, provides a compelling story. She tells me her husband has slowly been losing interest in life over the past few years. He had formerly been an outgoing, sociable individual, hard-working and helpful around the home. However, this is all changing. His motivation has decreased. He has lost interest in his work and his performance is a cause for concern in his employers. He has started to neglect his personal appearance. 

After detailed inquiry, it becomes clear he has developed apathy, one aspect of a personality change linked to a condition like MS.

Significantly, he denies feeling depressed.  He does not see his behaviour as problematic. After all, he reasons, he still goes to work and brings in a salary. After further detailed inquiry, it becomes clear that he has developed apathy, one aspect of a personality change linked to a condition like MS.

In another clinical example, a 42-year-old woman has been referred to me by her family doctor because of her irritable outbursts. She has more advanced MS and requires a scooter to get around. She denies feeling depressed and seems uncertain why the referral has been made. However, her husband says she has undergone something of a character change. She had always been a fairly mild individual, sociable and pleasant in her interactions. However, as her MS has progressed, she has become increasingly irritable with a short fuse. After taking a careful clinical history, it became apparent that her personality change is of the aggressive and at times labile and disinhibited subtype .

These clinical examples illustrate profoundly different personality alterations linked to MS. The labile and aggressive subtypes are labels that are part of the American Psychiatric Association’s (APA) classification of Personality Change Due to a Medical Illness such as MS.

There is, however, another approach to viewing personality change, the 5-Factor model that refers to five basic personality traits, namely neuroticism, extroversion, conscientiousness, agreeableness and openness to experience.

In my experience, treating this personality change is one of the most demanding and challenging aspects of clinical care. It is important to note that 5-Factor model treatment targets specific symptoms and as such, the methods will not differ according to how the personality change is classified, unlike the APA approach.

To begin with, this unraveling of personality is not reversible. It reflects the presence of brain damage in key regions that determine one’s behaviour. As both examples above reveal, the individual may lack insight into personality changes, further complicating management.

Loved ones frequently feel overwhelmed to see these profound changes. As these partners often tell me, “I no longer recognize the person I married.”

My approach is to combine psychoeducation with supportive psychotherapy and, in certain cases, psychotropic medication as well. To begin with, I explain to the individual and their family members what is going on medically. This point is pivotal given that loved ones frequently feel overwhelmed to see these profound changes. As these partners often tell me, “I no longer recognize the person I married.” Education can help both people with MS and their loved ones understand where this behavioural change comes from, that the apathy, irritability or disinhibition is not voluntary or willful.

The psychotherapy that I administer is frequently supportive. On occasion, I try behaviour modification, but this is seldom effective. For the person who is irritable, disinhibited and aggressive, I prescribe an array of psychotropic medications that can soften, and in some instances, prevent these outbursts. These medications include the selective serotonin reuptake inhibitors and selective noradrenergic reuptake inhibitors. When it comes to apathy, I sometimes prescribe psychostimulant medication to try to shift the individual’s reluctance to engage as before. However, the yield from these various therapies is uncertain at best and the prognosis associated with this condition is typically poor.

Moreover, personality change secondary to MS is often accompanied by underlying cognitive difficulties, namely challenges with memory, processing speed and executive functioning. This further complicates management for, like anything in medicine, the more extensive the array of comorbid problems, so the prognosis worsens with treatment becoming more complex.

There is no controversy when it comes to the diagnosis of personality change. Rather, the bigger issue is that the diagnosis is frequently missed. Unfortunately, the condition can easily be misconstrued as anger or depression – or brushed aside. It is therefore crucial for both the medical community and people caring for or living with MS patients to recognize it and understand why it arises.

The comments section is closed.

1 Comment
  • Rob Murray, DDS [ret'd] says:

    It may be that medicine has lost its way and that doctors are no longer searching for the root cause of illness. The rheumatologist isn’t interested in what is causing your arthritis. What is fuelling the epidemic of autoimmune diseases? Could it be the development of powerful immunosuppressants that provide life-time annuities to the pharmaceutical industry? The long-term disability insurance industry doesn’t want to have to deal with chronic illness. Shareholder preferences are controlling things; Goldman Sachs says that shareholders are no longer interested in cures, vaccines or new antibiotics. The paradigm of modern medicine is to palliate with treatments. How about some cures? I phoned my late father’s neurologist to discuss this but was told not to worry because they are coming out with new treatments all the time. These industries pay for political parties, research and medical schools.

    Historically inflammation was usually found to be due to infection. Pathologists with microbiological lab skills are no longer being trained. More fine tissue work and research is required. Long Covid may change this; we shouldn’t forget that pandemics disable people. It is now felt that in many cases such as Ebola these infections live on in tissue reservoirs only to re-emerge months or years later after treatment stops. It appears that the symptoms overlap and have common pathways that may involve the vagus nerve which allows infections to gain access, not just nervous tissue, but the brain. Psychiatrist, Robert C. Bransfield is straight forward with patients and tells them “of course you are sick, your brain is infected.” It used to be felt that the brain was sterile but with new techniques of studying the microbiome we find microbes in the brain and in cancerous tumours.

    Infectious disease doctors are very unhappy with microbial infections that can cause neurological disease. There are 4 different types of MS and they don’t know what the root cause is nor are they looking. I think we can now say in many cases that MS doesn’t just look like Lyme, it is Lyme disease. The problem is specialists work in silos. If there is no test for a disease then it doesn’t exist in medical minds. There is the story of the 19-year old who was sent to the psychiatrist for depression. The psychiatrist treated him with long-term antibiotics and the patient was cured. Dr. Brian Fallon has written papers on psychiatric illness in children caused by tick-borne disease. Certainly, Bartonella and Babesia can produce psychiatric illness but this is not taught in medical school.

    Medical doctors have known for over 40 years thanks to the work of pathologist Dr. Alan B. MacDonald that Borrelia can cause Alzheimer’s but have chosen to ignore this. In 2019 Sharon Begley in STAT wrote a wonderful article on this: “The maddening saga of how an Alzheimer’s ‘cabal’ thwarted progress toward a cure for decades.”

    They have finally recognized that myalgic encephalitis is real but they don’t know what they are searching for and they are looking in the wrong places.

    For more see “CHRONIC, the Hidden Cause of the Autoimmune Pandemic.., 2020” by Dr. Steven E Phillips, Crypto-infections: Denial, censorship and repression – the truth about what lies behind chronic disease, Christian Perronne, 2021 and YouTube videos of Amy D. Proal, PhD and the PolyBio Research Foundation. Amy is cutting through the silo walls.


Anthony Feinstein


Anthony Feinstein, Ph.D., is a neuropsychiatrist and professor of Psychiatry at the University of Toronto. His research follows two strands – the search for cerebral correlates of behavioural disorders associated with multiple sclerosis, and exploring the psychological effects of conflict on journalists. He is the author of seven books, most recently, Mind, Mood and Memory in Multiple Sclerosis.

Republish this article

Republish this article on your website under the creative commons licence.

Learn more