These assessments measure changes in brain function, cognition and mood in the context of neurological disorders [e.g. Dementia, Multiple Sclerosis, Parkinson's Disease, etc.] and general medical conditions affecting the brain [e.g. brain tumours, diabetes, cardiac issues, chemotherapy, etc.]. Neuropsychological data are vital in refining diagnoses, evaluating response to treatment and to monitor changes in cognition and function over time with degenerative or fluctuating neurological disorders. For example, an assessment may inform diagnoses related to a person’s subjective memory complaints. These symptoms may be the sign of early dementia/Mild Cognitive Impairment or be the result of mood changes or other psychological factors. Results of a neuropsychological assessment can clarify this diagnosis, leading to appropriate treatment. Assessment can also help differentiate between subtypes of diseases. A diagnosis of Dementia, for example, can be refined further through neuropsychological testing to categories such as behavioural variant Frontal Temporal Dementia, Semantic Dementia, Primary Progressive Aphasia, Lewy Body Dementia, Alzheimer's Disease, etc. Arriving at the correct diagnoses in these cases not only guides appropriate treatment, but also has a psychological impact relating to a patient's self–identity and appropriate life planning.