Which condition is primarily characterized by cognitive decline and memory loss?

Alzheimer's disease is primarily characterized by cognitive decline and memory loss, making it the correct choice. This condition is a form of dementia that progressively affects memory, thinking skills, and the ability to carry out simple tasks. As Alzheimer's disease advances, individuals may struggle to remember recent events or recognize familiar faces, which significantly impacts daily living and personal relationships. The cognitive decline associated with Alzheimer's is due to the accumulation of plaques and tangles in the brain, leading to neuronal loss and brain shrinkage over time.

In contrast, Cognitive Behavioral Therapy is a therapeutic approach aimed at helping individuals manage their thoughts and behaviors but does not directly relate to cognitive decline or memory issues. Rheumatoid arthritis is an autoimmune disorder that primarily affects the joints and can cause physical disability but is not directly linked to cognitive decline. Multiple sclerosis is a neurological condition that can affect various bodily functions, including some cognitive functions, but its primary symptoms are motor and sensory deficits rather than memory loss. Therefore, Alzheimer's disease stands out as the condition specifically associated with cognitive decline and memory loss.