would point at a vascular type of dementia. These tests do not pick up diffuse metabolic changes associated with dementia in a person who shows no gross neurological problems (such as paralysis or weakness) on a neurological exam. The functional neuroimaging modalities of SPECT and PET are more useful in assessing long-standing cognitive dysfunction, since they have shown similar ability to diagnose dementia as a clinical exam and cognitive testing. The ability of SPECT to differentiate vascular dementia from Alzheimer's disease, appears superior to differentiation by clinical exam. The value of PiB-PET imaging using Pittsburgh compound B (PiB) as a radiotracer has been established in predictive diagnosis, particularly Alzheimer's disease. Prevention Risk factors An influential review increased the number of associated risk factors for dementia from nine to twelve in 2020. The three newly added risks are over-indulgence in alcohol, traumatic brain injury, and air pollution. The other nine risk factors are: lower levels of education, high blood pressure, hearing loss, smoking, obesity, depression, inactivity, diabetes, and low social contact. Many of these identified risk factors including, the lower level of education, smoking, physical inactivity and diabetes, are modifiable. Several of the group are known vascular risk factors that may be able to be reduced or eliminated. Managing these risk factors can reduce the risk of dementia in individuals in their late midlife or older age. A reduction in a number of these risk factors can give a positive outcome. The decreased risk achieved by adopting a healthy lifestyle is seen even in those with a high genetic risk. In addition to the above risk factors, meta-analyses indicate that there is robust evidence that other psychological traits, including personality (high neuroticism, and low conscientiousness), low purpose in life, and high loneliness, are risk factors for Alzheimer's disease and related dementias. For example, based on the English Longitudinal Study of Ageing (ELSA), research found that loneliness in older people increased the risk of dementia by one-third. Not having a partner (being single, divorced, or widowed) doubled the risk of dementia. However, having two or three closer relationships reduced the risk by three-fifths. The two most modifiable risk factors for dementia are physical inactivity and lack of cognitive stimulation. Physical activity, in particular aerobic exercise, is associated with a reduction in age-related brain tissue loss, and neurotoxic factors thereby preserving brain volume and neuronal integrity. Cognitive activity strengthens neural plasticity and together