Depression, nutritional deficiencies, side-effects from medications and emotional distress can all produce symptoms that can be mistaken as early signs of dementia, such as communication and memory difficulties and behavioural changes.

Although the early signs vary, common early symptoms of dementia include:

• memory problems, particularly remembering recent events.
• increasing confusion.
• reduced concentration.
• personality or behaviour changes.
• apathy and withdrawal or depression.
• loss of ability to do everyday tasks.

A person with dementia feels confused more and more often. When they can’t make sense of the world or get something wrong, they may feel frustrated and angry with themselves. They may become angry or upset with other people very easily.

How do they test for dementia? There is no single diagnostic test for Alzheimer’s disease and other causes of dementia. Doctors use a number of different assessments and tests, including a physical exam, lab tests, analysis of medical history, cognitive, and neuropsychological tests, to diagnose dementia.

Depression. Thyroid problems, such as hypothyroidism. Additional neurological conditions. Autoimmune neurological disorders and paraneoplastic disorders, which are conditions that can cause rapidly progressive dementia.

However, people with dementia can also have visual difficulties because the dementia affects the parts of their brain that handle visual information coming from the eyes. This means they will have visual problems, but have healthy eyes.

Visual hallucinations (seeing things that are not really there) are the most common type experienced by people with dementia. They can be simple (for example, seeing flashing lights) or complex (for example, seeing animals, people or strange situations).