Your loved one may be experiencing personality changes because of the person’s struggles with cognitive changes. Aware of problems with memory and other thinking skills, the person with dementia has to work hard to compensate. This means greater focus on keeping track of things, performing well, and possibly hiding deficits from loved ones. All that concentration takes energy—causing the person to unintentionally become more focused on himself or herself, to the exclusion of others.
What you can do to help:
Simply being aware of the cause is a huge help—don’t take it personally.
Be empathetic to the person’s struggles and try to help them remember and do things as best as you can.