Dementia Information Why is diagnosis so important? A proper medical assessment of someone who appears to be developing the symptoms of dementia is required because: The cause of the person's problems may be treatable. It means that the most appropriate care and advice can be provided. The earlier a diagnosis is made, the more effective a treatment can be because the brain has is likely to have suffered less damage in the earlier stages of disease. It allows access to support services geared to the person with dementia and their carers. It allows those with dementia to make plans for the future, along with their families.