轻度认知障碍（MCI）：症状、病因及后续措施

Mild cognitive impairment, often shortened to MCI, describes changes in memory or thinking that are greater than expected for your age, but not severe enough to stop you managing everyday life. It sits between typical ageing and dementia.

Hearing the term can be worrying. MCI does not always lead to dementia, and some people stay stable or even improve. This guide covers the signs, possible causes, how MCI is assessed, and practical steps you can take.

What is mild cognitive impairment?

Dementia Australia describes MCI as a brain condition involving subtle changes to memory and thinking, and notes that it is not a normal part of ageing. healthdirect explains that people with MCI can continue to do their normal daily tasks, and that it is also called mild neurocognitive disorder.

The key difference from dementia is everyday function. In dementia, changes in thinking are significant enough to interfere with independence in daily life. In MCI, you may need to put in more effort or use more reminders, but you can still manage.

Two main types

• Amnestic MCI mainly affects memory. A person might forget appointments, names or recent events, or often lose things.
• Non-amnestic MCI mainly affects other thinking skills, such as language, concentration, decision making or visual perception.

Common signs

Signs are usually subtle and may be noticed first by the person themselves or someone close to them. They can include:

• forgetting recent conversations, events or appointments more often than before
• repeating questions or stories
• losing your train of thought, or trouble following a film or book
• more difficulty finding words
• finding planning, decisions or multi-step tasks harder, such as managing bills
• getting disoriented in less familiar places
• relying more on lists and reminders than you used to
• feeling more anxious, irritable or flat, sometimes in response to the changes

Everyone has off days. The pattern that matters is a change from your usual level that has lasted for months.

What can cause MCI?

MCI describes a level of difficulty, not a single cause. Dementia Australia lists a range of possible causes, including:

• side effects of medicines
• sleep deprivation
• anxiety
• stroke or other vascular disease (conditions affecting blood vessels in the brain)
• traumatic brain injury
• brain changes related to Alzheimer’s disease

Depression, heavy alcohol use and other health conditions can also affect thinking. Some of these causes can be treated or improved, which is why a thorough assessment matters.

Does MCI lead to dementia?

Not always. Dementia Australia states that people with MCI are three to five times more likely to develop dementia than others their age. It also notes that a substantial proportion of people with MCI remain stable or even improve, and that there is not yet a way to tell which people with MCI will go on to develop dementia.

This uncertainty can be hard to live with. It is also why follow-up matters. Repeating an assessment after a suitable interval, often 12 months or more, can show whether thinking is stable, improving or changing.

How MCI is assessed

Assessment usually starts with your GP. Dementia Australia describes an assessment that may include:

• a medical history and physical examination
• blood and urine tests to look for treatable causes
• a psychological evaluation, including mood
• tests of memory and thinking
• brain scans

Your GP may refer you to a geriatrician, neurologist, psychiatrist or memory clinic.

The role of a neuropsychological assessment

Short screening tests can flag a concern but may not pick up subtle changes. A neuropsychological assessment looks at memory, attention, language, speed of thinking, visual skills and executive functions (planning, organising and problem solving) in detail. Results are compared with people of a similar age and background.

This can help to:

• confirm whether thinking has changed more than expected for your age
• describe which skills are affected and which remain strong
• point towards likely causes, including whether mood or sleep may be playing a part
• provide a baseline, so future change can be measured accurately
• guide practical strategies for daily life

Next steps after an MCI diagnosis

Look after your brain health

Dementia Australia reports that the 2024 Lancet Commission identified 14 modifiable risk factors for dementia, and estimated that up to 45% of dementia cases worldwide could be prevented or delayed. The factors include high blood pressure, high LDL cholesterol, diabetes, hearing and vision loss, smoking, excessive alcohol use, physical inactivity, depression and social isolation.

Practical steps include:

• seeing your GP regularly to manage blood pressure, cholesterol and diabetes
• having your hearing and eyesight checked, and using aids if needed
• moving your body most days, in a way you enjoy
• staying socially connected and mentally active
• getting help for low mood, anxiety or sleep problems
• cutting back on alcohol and stopping smoking

Use everyday strategies

Routines, a single calendar or diary, phone reminders, and keeping important items in one place can reduce the load on memory. Many people find these tools help them feel more in control.

Plan ahead

While you are well, it is a good time to make or update a will and appoint someone you trust to make decisions for you if needed, such as through an enduring power of attorney. Getting legal advice now keeps decisions in your hands.

Look after your wellbeing

It is common to feel shocked, anxious, sad or even relieved after hearing you have MCI. Some people worry that every forgotten name is a sign of decline. Talking with someone you trust, or with a psychologist or counsellor, can help you make sense of the diagnosis and focus on what you can control.

Family members may have their own worries. It can help to talk openly about what support is useful and what is not. For example, a person might prefer a gentle prompt to check the calendar rather than a partner stepping in to take over tasks.

Keep doing what matters to you

MCI does not mean you have to stop working, volunteering, travelling or enjoying hobbies. You may need to make some changes, such as allowing more time or writing things down, but staying engaged in meaningful activities is good for mood and for brain health.

Find support

Dementia Australia runs Mild Cognitive Impairment: Thinking Ahead, a free five-week program for people with MCI. You can call the National Dementia Helpline on 1800 100 500 for information and support.

Invictus Health 能提供哪些帮助

Our neuropsychologists provide neuropsychology assessments for people with memory or thinking concerns, including follow-up assessments to track change over time. Where planning ahead is a concern, we also offer 决策能力评估. Adjusting to a diagnosis can be hard, and our counselling and psychology team can support you and your family.

This article is general information only. Please talk with your GP or another qualified health professional about your own situation.