East Asian Arch Psychiatry 2013;23:76-7

EDITORIAL

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Alzheimer’s disease (AD), the commonest cause of dementia, was first described by Dr Alois Alzheimer more than 100 years ago. Unlike most mental disorders, neuropathological changes associated with AD represented by neurofibrillary tangles and senile plaques, were identified at the outset. However, progress in understanding this disorder has been limited by the lack of suitable scientific tools in the first half of the 20th century.

With advances in technology, dementia has emerged as a focus of psychiatric research in recent decades. Since the 1980s, exciting developments have been made successively: identification of beta-amyloid (1984), identification of the tau protein (1986), identification of the first deterministic AD gene (1987), identification of the first AD risk factor gene (1993), approval of the first AD drug (1993), announcement of the first transgenic mouse model (1995), and the first report on Pittsburgh Compound B in 2004.¹ One of the latest milestones is the incorporation of biomarkers into the updated diagnostic criteria of dementia due to AD issued by the National Institute on Aging/ Alzheimer’s Association,² which aids early diagnosis of dementia and monitoring of disease progression.

Despite the above major discoveries, many questions about dementia remain unanswered. In the current issue of East Asian Archives of Psychiatry, a number of dementia researchers in Asia have contributed new knowledge to the understanding and management of this group of disorders, with particular relevance to the Asian population.

Neuropsychiatric symptoms are very common, and are associated with poorer quality of life both for caregivers and for care-recipients. Using neuroimaging examinations, Tsai et al³ investigated the role of the posterior cingulate gyri and frontal cortex in the manifestation of 2 of the commonest neuropsychiatric symptoms, namely agitation and depression, in patients with AD in Taiwan. These authors reported that agitation and depression were correlated with different neurochemical metabolites in specific brain regions, suggesting separate pathophysiologies for different neuropsychiatric disturbances.

Increasing attention has also been paid to non-AD dementia, including frontotemporal dementia. A number of variants of frontotemporal dementia have been proposed, but the differentiation between some variants may not be clear cut. Ichimi et al⁴ examined 1723 consecutive patients attending a tertiary memory clinic in Japan, and found that those with semantic dementia did not differ from those with semantic variant of primary progressive aphasia in terms of clinical characteristics and language function. These authors suggested that the 2 variants might represent the same condition.

Prevention is always better than cure. In a cross- sectional study, Fung and Lam⁵ studied the lifestyle determinants of cognitive function in 380 community- dwelling non-demented older adults in Hong Kong. These researchers examined the association between 6 groups of leisure activities undertaken by the participants and their cognition, and found that those who frequently participated in cognitive activities and spiritual activities performed better on cognitive tests. Although longitudinal studies are required to confirm the causal relationship, the results shed some light on suitable activities that may help to build up the cognitive reserve of Asian people.

Yusoff et al⁶ demonstrated an excellent example of translating best evidence in dementia care into everyday clinical practice. In 2010, the Ministry of Health Malaysia released the second edition of the Clinical Practice Guidelines (CPG) for Management of Dementia.⁷ Researchers subsequently organised a CPG training programme for health care professionals, including doctors and pharmacists. After attending the programme, participants reported improvement in dementia knowledge, which was accompanied by an increasing number of referrals to the local memory clinic.

In Asian countries, it is not uncommon to consider cognitive decline as an integral part of the normal ageing process. It is therefore important to develop a locally validated screening instrument that is sensitive for detecting early dementia or mild cognitive impairment. In the current issue of the Journal, we have included a validation study by Dominguez et al,⁸ who showed that the Filipino version of the Montreal Cognitive Assessment was a reliable assessment instrument for older adults in the Philippines.

Studies have suggested that the paraoxonase-2- 311C allele, a possible risk factor for dementia, is more prevalent in Han Chinese people. Mu et al⁹ examined the paraoxonase-2-311 polymorphism in 84 older Chinese people with dementia. These researchers also probed the relationship between lipid profiles and insulin levels with different types of dementia.

This special issue is nicely concluded by Suh’s proposal on a new way to interpret cognitive test scores.¹⁰ Suh opined that a single cutoff score was undesirable as it would result in a higher rate of false-positive and false- negative results. An individualised score determined by the testee’s age and education was suggested to be a better alternative. This author also recommended adopting the 2 standard deviation notions in the diagnosis of dementia.

Rapid ageing of the Asian population will be associated with an exponential rise in the prevalence of dementia and related cognitive disorders in the next few decades. Exciting developments in different facets of basic and clinical research will not only improve knowledge, but also optimise clinical care and quality of life of people living with this disorder.

Dr Wai-Chi Chan, MRCPsych, FHKCPsych, FHKAM (Psychiatry)
Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China.

Prof. Linda Chiu-Wa Lam, MD, FRCPsych, FHKCPsych, FHKAM (Psychiatry) (email: cwlam@cuhk.edu.hk)
Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China.

References

1. Alzheimer’s Association [Internet]. Major milestones in Alzheimer’s and brain research. Available from: http://www.alz.org/research/science/major_milestones_in_alzheimers.asp. Accessed 10 September 2013.
2. McKhann GM, Knopman DS, Chertkow H, Hyman BT, Jack CR Jr, Kawas CH, et al. The diagnosis of dementia due to Alzheimer’s disease: recommendations from the National Institute on Aging- Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer’s disease. Alzheimers Dement 2011;7:263-9.
3. Tsai CF, Hung CW, Lirng JF, Wang SJ, Fuh JL. Differences in brain metabolism associated with agitation and depression in Alzheimer’s disease. East Asian Arch Psychiatry 2013;23:86-90.
4. Ichimi N, Hashimoto M, Matsushita M, Yano H, Yatabe Y, Ikeda M. The relationship between primary progressive aphasia and neurodegenerative dementia. East Asian Arch Psychiatry 2013;23:120- 5.
5. Fung AW, Lam LC. Spiritual activity is associated with better cognitive function in old age. East Asian Arch Psychiatry 2013;23:102-8.
6. Yusoff S, Koh CT, Mohd Aminuddin MY, Krishnasamy M, Suhaila MZ. Initial evaluation of the training programme for health care professionals on use of the Malaysian Clinical Practise Guidelines for management of dementia. East Asian Arch Psychiatry 2013;23:91-101.
7. Clinical Practice Guidelines for Management of Dementia. 2nd ed. Malaysian Health Technology Assessment, Ministry of Health Malaysia; 2009.
8. Dominguez JC, Orquiza MG, Soriano JR, Magpantay CD, Esteban RC, Corrales ML, et al. Adaptation of the Montreal Cognitive Assessment for elderly Filipino patients. East Asian Arch Psychiatry 2013;23:80-5.
9. Mu N, Xu SC, Chang Q, Rao DP, Chen JP, Ma C. Study of lipids, insulin metabolism, and paraoxonase-2-311 polymorphism in patients with different subtypes of Alzheimer’s disease (translated version). East Asian Arch Psychiatry 2013;23:114-9.
10. Suh GH. Adoption of two standard deviation notions of mental retardation for the diagnosis of dementia. East Asian Arch Psychiatry 2013;23:78-9.