Dementia often develops after a stroke, brain injuries, or in certain neurodegenerative diseases, and it typically follows a lengthy phase of subtler cognitive changes known as predementia. In many cases, the early signs are noticed by the individual first, while family and friends may not yet see a clear picture. This perspective comes from Ekaterina Demyanovskaya, a medical scientist and neurologist at the Gemotest Laboratory, who explains this progression in clinical terms for a broader audience.
During the stage of subjective cognitive impairment, tasks that once seemed routine may cause more effort. For example, remembering day-to-day to-do lists becomes cumbersome, so people rely on reminders on their phones or written notes. Those in cognitively demanding professions often feel alarm, and they may seek medical advice, yet standard tests might not reveal measurable memory loss at this point. This nuance illustrates how early changes can be subtle and variable from person to person. [Citation: clinical observation guidelines]
Over time, these symptoms become more evident to others. Many patients present with complaints about memory, and objective assessments may begin to show a decline in overall cognitive function. The condition then advances to the next stage, termed mild cognitive impairment or MCI. In this phase, individuals may struggle with complex words, confusing similar-sounding terms, and reduced concentration. It is common for areas of interest to shift dramatically, such that someone who specialized in a technical field might suddenly gravitate toward politics or education. [Citation: neuropsychology standards]
As the disease progresses, the brain’s functioning deteriorates beyond memory alone. Not only memory regions are affected, but also areas essential for critical thinking, complex skills, and behavior regulation. The trajectory often follows a path from MCI to a more pronounced stage of cognitive decline that is easier to recognize by others and by clinicians. [Citation: neurology literature]
The subsequent phase, moderate cognitive impairment, is where the decline becomes more clearly outside the age-related norm. In this stage, people may struggle to perform prior professional duties, yet some can still pursue work with adjustments. They might manage daily tasks more independently, such as shopping, and can still enjoy reading, watching television, and grasping the overall meaning of content. However, when asked to describe specifics from a task or a project, recalling those details may prove difficult. [Citation: clinical progression models]
Recognizing the transition from pre-dementia cognitive changes to dementia is crucial because it signals a real shift in social, work, and home life. A person might no longer carry out usual activities with the same capacity and could become reliant on care from others. This recognition helps families and caregivers plan for support and safety. [Citation: care planning guidelines]
Neuropsychological testing can reveal cognitive changes before dementia becomes fully evident. These assessments typically evaluate five core brain functions: memory, perception and recognition, language, motor skills, and reasoning. In practical terms, a patient might be asked to memorize a short list, name familiar objects such as a phone, a pen, and a mug, demonstrate basic tasks like combing hair or cutting paper, and perform a simple drawing or clock-face task. To gauge verbal fluency and abstract thinking, an examiner might request as many words as possible in one minute or ask for similarities between items such as tomato and cucumber, hat and cap. The pattern of errors and the overall score help clinicians determine the level of cognitive decline. [Citation: standardized neuropsychological protocols]
In this context, early cognitive screening is a valuable tool for identifying shifts in mental function before dementia fully develops. It enables timely intervention, planning for daily living needs, and discussion of strategies to maintain quality of life. [Citation: preventive neurology practice]
As the brain changes unfold, medical teams emphasize a person-centered approach. The focus is on supporting independence wherever possible, while recognizing when more intensive care and supervision become necessary. The path from predementia to dementia is not merely a medical timeline; it is a signal to adapt routines, environments, and supports to preserve safety and dignity. [Citation: patient-centered care studies]
In clinical terms, the transition from predementia to fully established dementia is a complex, multi-step process that requires careful assessment, continued monitoring, and collaborative decision making among patients, families, and healthcare providers. The goal is to optimize function, reduce risk, and maintain meaningful engagement in daily life. [Citation: longitudinal dementia research]
Finally, ongoing research continues to refine our understanding of these stages, with a growing emphasis on early detection, prevention strategies, and personalized care plans that align with real-world needs across diverse populations. [Citation: current dementia research]