Mild cognitive impairment (MCI): causes, assessment and outlook

Alzheimer's Society breaks the words down. Mild means symptoms may be troubling but the person manages themselves well and does most everyday activities. Cognitive covers thinking, learning, remembering, understanding, paying attention, communicating and processing sensory information. Impairment means not working as well as expected for the person's age and background.

Some memory and concentration lapses become more common from around 60, the charity notes, and rarely stop normal activities. The difference with MCI is that the problems are worse than expected for age and are regular. Many people struggle with memory when tired, unwell or stressed, so a problem that persists beyond a few months is the point at which it is worth raising with a GP.

MCI involves problems in one or more thinking skills. Alzheimer's Society gives examples:

• Memory or learning: trouble remembering recent events or learning new things.

• Reasoning: struggling to make decisions or work through everyday problems.

• Attention: finding it harder to focus or to filter out distractions.

• Language: difficulty finding the right word in conversation.

• Motivation: less interest in usual activities or hobbies.

Alzheimer's Research UK lists depression, stress and anxiety, vitamin deficiencies, thyroid disorders, autoimmune conditions, infections, side effects from medication, and sleep disorders such as sleep apnoea as health problems that can cause MCI. MCI can also be caused by the early stages of Alzheimer's disease or another dementia, and it is important to know which. The charity adds that some of these conditions, including sleep apnoea, some autoimmune diseases and depression, can raise the risk of dementia later, but many can be treated or managed if found early.

Because older adults often take several medicines, a review of the medicine list is an obvious early step: Alzheimer's Society names the side effects of medicines as one possible cause of MCI.

Alzheimer's Society says thinking problems can be assessed at the GP or at a memory service, and that diagnosing MCI can help people get any help or support they need. Taking a symptom checklist, which the charity provides to print, helps describe changes. Bringing someone who knows you well is often useful.

Alzheimer's Research UK explains that when tests show brain changes linked to Alzheimer's, such as protein build-up in spinal fluid or on specialised brain scans, memory clinic doctors may use the term "MCI due to Alzheimer's disease". This is used only when symptoms are not affecting daily life. These tests are more likely to be offered in memory clinics that are part of a hospital, and are not available through a GP appointment alone. Knowing the cause helps guide advice, treatment and whether someone might be suitable for research studies.

Alzheimer's Research UK says that if the cause is a treatable condition such as a thyroid disorder or vitamin deficiency, the doctor may prescribe treatment for it. Research into non-drug treatments such as memory training and computer-based brain training has so far given mixed results. Doctors may suggest practical tips such as keeping a calendar or diary and ways to improve brain health. The charity says that for MCI caused by early Alzheimer's disease, two new medications licensed to slow the underlying disease are not available through the NHS.

Where the cause cannot be pinned down and there is no suitable treatment, people can still take steps to protect brain health while waiting for answers, and can register interest in dementia research.

Alzheimer's Society points out that dementia always gets worse over time, which is not always the case with MCI. Alzheimer's Research UK says that when MCI is caused by early Alzheimer's disease, vascular dementia or another dementia, symptoms get worse and begin to affect everyday activities; if you notice that happening, speak to the doctor. When MCI is not caused by a dementia, memory and thinking problems may go back to normal with the right treatment. The charity also says that the true number of people with MCI is probably higher than those diagnosed, because many do not see a GP about it.