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1　History

Jon first consulted you 12 months ago.After several visits over a 6 month period you made a diagnosis of depression and initiated treatment with Fluoxetine together with some interpersonal counselling (IPC).At the time of the initial diagnosis you had noted that amongst Jon′s depressive symptoms,memory complaints were prominent.You explained to Jon that you felt these complaints were part of his depression and would resolve with treatment with an antidepressant.However,after 6 months,the last 2 at a dose of 40 mg/day Fluoxetine,Jon′s memory problems have persisted.

2　Further history

Jon reports that his mood feels good,other than his worries about his memory.His sleep is normal,his appetite is also normal,he has his interest and motivation back,but he forgets things.He indicates he does not know how his father′s dementia first presented,but he vividly recalls the later stages of his father′s illness.Jon reports he′s frustrated as he can′t remember simple things,where he′s put things,has missed a couple of appointments,and his wife has told him he repeats things.By contrast,his memory for things in the past is as good as ever.

3　Examination

Jon presents as well dressed,but curiously he′s wearing odd socks.And,again somewhat incongruently,he has a stain on his tie.He seems somewhat tense but denies feeling anxious,other than about his memory,and denies feeling depressed.His affect is not depressed.There is no depressive thought content and no perceptual disturbance.His attention and concentration are impaired,and as was the case when initially seen he has problems with immediate and short term memory.

4　Questions

4.1What is your probability diagnosis？

4.2What further assessment is required？

4.3How should Jon be treated？

5　Answers

5.1The probability diagnosis is possible dementia.Jon′s depression has resolved with treatment,yet his memory problems persist.Whilst antidepressant medication can cause some disturbance of cognition,it is generally mild,and is more common with other classes of antidepressants than it is with the SSRI medications.Thus,this is not likely to be the cause of Jon′s complaints.

Importantly,some normal older people,particularly those who are particularly concerned that they may be at increased risk of dementia may worry about and seek reassurance that they are not dementing.This is most common in high achievers who notice age related changes in cognitive speed,memory and concentration.It is important to carefully test Jon′s memory to make this differentiation[1].

5.2Further history taking should focus on risk factors for Alzheimer′s disease,vascular dementia,and other possible causes such as head trauma and alcohol abuse.Thus,ask about family history,history of stroke,hypertension,smoking,diabetes mellitus and hypercholesterolemia.

The most useful history will be obtained from someone who knows Jon well- his wife.It is important to check the duration and rate of onset of the memory problems,and have her account of any cognitive and behavioural change.

Jon has had some initial investigations to exclude physical problems but these need to be extended now to detect any potentially reversible cause of dementia.Investigations should include a CT head scan and blood tests including HIV and syphilis serology,metabolic screen,and assessment for nutritional deficiency.Identification and correction of organic problems may not necessarily reverse the dementia but will improve the patient′s quality of life.

More extensive cognitive testing is an essential part of the assessment.In addition to any simple testing you have already done,it is important to formally test cognition,most often this is done using an instrument such as the Mini Mental State Examination (MMSE)[2].Generally speaking,a score of 23 or less is suggestive of significant cognitive impairment.

5.3If your further assessment confirms the likely diagnosis of dementia,further treatment will depend on the presumed cause of the dementia.Alzheimer′s disease is the most common cause of dementia (60%),followed by vascular disease and Lewy body dementia (each 10% of cases).Given Jon has a family history of Alzheimer′s disease,no history of vascular problems and has not reported any visual hallucinations (seen in Lewy body dementia) the most likely cause is Alzheimer′s disease.

The cholinesterase inhibitors may produce small but worthwhile improvements in memory,energy and mood.However,they have significant side effects including nausea,diarrhoea,vivid dreams and leg cramps.Jon should be referred to a psychiatrist or psychogeriatrician for further assessment before he is started on these medications.

Longer term management includes the detection and treatment of co-occurring depression,delirium or psychotic symptoms;management of disturbed behaviours which become more common as dementia worsens;support of family and carers;and attention to legal and ethical issues such as how long should the person continue to drive a car,capacity to make decisions and testamentary capacity[3].

Notes：

Mini mental state examination(MMSE):It is a 30-point questionnaire test which is used to screen for cognitive impairment.The tool was introduced into China in middle 1980s,and was used in mental health research and clinical practice.For more informationabout Chinese version MMSE,see Zhang 1995[4].

Cholinesterase inhibitors:rivastigmine,donepezil,galantamine are used in Chinese healthcare system.Huperzine (a Chinese developed medicine) is also used.

1Conner DO,Piterman L,Darvall L.Common mental health problems in the elderly//Blashki G,Judd F,Piterman L.General practice psychiatry[M].McGraw Hill Medical,2007:257-276.

2Folstein M,Folstein S,McHugh P.The mini mental state:A practical method for grading the cognitive state of patients for the clinician[J].Journal of Psychiatric Research,1975,12:189-198.

3Therapeutic guidelines[Z].Psychotropics,2008.

4ZHANG Ming-yuan,Elena Yu,HE Yan-ling.Epidemiological tool for dementia study[J].Journal of Shanghai Mental Health,1995,7(1):3-5.