Chronic alcohol use disorder is an important cause of major neurocognitive disorder. There are several suggested mechanisms for how alcohol use disorder leads to major neurocognitive disorder. Medical treatment of alcohol use disorder can help limit the late effects of alcohol use. Alcohol-induced major neurocognitive disorder can be partially reversible with abstinence but this depends on the severity of the pathology.

Sundowner syndrome is a common neuropsychiatry syndrome seen in residents of long-term care. Several theories are proposed to explain the pathophysiology and contributing factors. Treatment options are also discussed.

Traumatic brain injury (TBI) is more common in older adults than any other age group. It is the most common fall-related injury in adults over the age of 65. The pathogenesis of TBI involves multiple mechanisms. Medications generally do not alter the course of the disease process but can treat the neuropsychiatric symptoms. Mood and anxiety disorders are commonly comorbid with TBI.

The chapter explores whether high-income countries are ready for the first disease-modifying Alzheimer’s disease (AD) treatment, approved in the USA in February 2021. It looks at the capacity to provide diagnostic services relative to the expected demand, institutional preparedness, and potential solutions to overcome capacity constraints. Wait times are projected to differ substantially. Initial average wait times range from 5 months in Germany to 28 months in Canada. In France, Canada, and Taiwan, we project it will take over a decade to clear the backlog of prevalent cases and to make a treatment accessible with little delay, because of scarcity of dementia specialists, and aggravated by the lack of financial and structural plannin. Potential solutions include broadening the dementia workforce by integration of primary care clinicians and other specialists, care models that leverage specialist time, and telecare-supported models. Better diagnostic technology to detect cognitive decline and the AD pathology in primary care settings and predictive models to triage patients show potential to improve access.