Not medical advice: this post is for information only. If you’re worried about a loved one, please contact a healthcare professional. Early assessment and support make a difference. When people think of seniors with dementia, they often picture memory loss. Memory is important, but dementia commonly brings changes in personality and behaviour that take families by surprise, shifts that can include altered tastes, slowing of every task, sudden self-focus, and rising frustration or agitation. Understanding these changes helps caregivers respond with patience and appropriate care, and it can point to specific diagnoses or treatable causes, so one knows when to get a trusted clinician involved.

seniors with dementia elderly man exercise care home nurse

  1. Changes in taste and food preferences

    People with neurocognitive disorders often report food tasting different, losing interest in certain flavours, or suddenly craving sweets or very strong flavours. Studies increasingly point to gustatory (taste) dysfunction and combined smell/taste changes in early and later stages of many dementias. These sensory shifts can alter appetite, weight, and mealtime behaviour. Treating oral health issues, checking medications, or adjusting menus (stronger flavours, familiar favourites) can make meals more appealing.

  2. Slowed thinking and action

    A very practical and upsetting change is that routine tasks take much longer. Seniors with dementia may move more slowly, need more time to answer questions, or struggle to complete multi-step activities. That “slowness” reflects processing-speed decline and impaired executive function — measures that predict functional difficulties and can appear early in cognitive decline. Allowing extra time, simplifying steps, and removing time pressure reduces stress for both the person and the caregiver.

  3. Rising frustration, irritability and agitation

    When communication gets harder and the world feels confusing, frustration often follows. Agitation and irritability are common behavioural symptoms in dementia and can be triggered by unmet needs (pain, fatigue, hunger), sensory overload, or an unfamiliar environment. These behaviours are real expressions of distress; responding by identifying triggers and using non-pharmacologic strategies (routine, calm tone, meaningful activities) is the recommended first step. If symptoms are severe or risky, medical assessment can guide safe treatment.

  4. Disinhibition and loss of filters

    Some people lose social filters: making blunt remarks, acting impulsively, or failing to respect boundaries. This is especially typical of frontal-lobe involvement (bvFTD) and can be frightening or even embarrassing for families. Gentle redirection, predictable structure, and environmental adjustments (privacy for dressing, supervision during finances) help manage risks while preserving dignity and as much autonomy as is possible. Specialist assessment can clarify cause and prognosis.

  5. A spike in self-focus

    One striking shift some families describe is that a previously warm, giving person grows much more self-centered: less interested in others’ feelings, more demanding, or oblivious to social norms. This can happen especially in frontotemporal dementia (FTD) and sometimes precedes other clear cognitive signs. Research shows that changes resembling reduced empathy, grandiosity, or pre-existing dramatic-personality traits can appear or become exaggerated as frontal brain systems are affected. When you see this, it’s not “bad character”; it’s the disease changing socio-emotional processing.

  6. Why these changes matter and what to do next

    Personality and sensory changes aren’t just “annoying”; they affect relationships, safety, nutrition, and care planning. Document what you notice (when it started, triggers, patterns), share that with a family doctor or geriatric clinic, and ask about reversible contributors (infections, medications, hearing or vision loss, depression). Behavioural approaches, caregiver training, and community support can reduce stress and improve quality of life for everyone.

If you notice unexpected personality shifts in a loved one or senior you care for, seek assessment from a medical professional. Early evaluation can help identify the type of dementia, rule out treatable causes, and connect you with support. Lynn Valley Care Centre in North Vancouver, British Columbia offers compassionate long-term care for seniors, with our 24/7 nursing staff trained to care for residents with complex health issues, including dementia and Alzheimer’s. Above all, remember: these behaviours are symptoms, not choices, and with the right help you can improve safety and comfort for your loved one and yourself. For more, see our blog on How to Senior-Proof Your Home.