Two groups of people commonly seek memory pills: students who are facing examinations, and elderly persons who find that they are becoming forgetful. Memory pills, however, are usually prescribed only to patients with dementia; that is, a condition generally associated with advancing age, and characterised by deterioration in intelligence, memory, and personality.

Are there pills which improve memory?

nCertain allopathic and herbal medicines are used to treat memory loss and the intellectual impairments of persons with Alzheimer's disease and other forms of dementia. The allopathic treatments include donepezil, rivastigmine, galantamine, hydergine, nicergoline, citicoline, piribedil, piracetam, and others; other drugs are under investigation. The herbal treatments include Chinese medicines such as ginkgo and ginseng, and Indian herbs such as Brahmi, Ashwagandha, Shankapushpi, and others. Proprietary herbal formulations are also marketed in India.

How effective are these medicines?

nAt best, these medicines improve memory by 10-20 per cent. More commonly, the medicines slow down the inexorable deterioration of memory and intellectual functions in patients with dementia. The real benefit, however, is the partial improvement in the ability of treated patients to conduct their activities of daily life. Also important is the associated reduction in caregiver burden.

Do these medicines have side effects?

nCertain of the medicines, such as donepezil, rivastigmine, and galantamine, may cause nausea, stomach disturbances, slowed heart rate, insomnia, or nightmares in a small proportion of patients. Otherwise, these medicines, including the herbs, are generally very well tolerated.

For how long are these medicines effective?

nDementia is usually progressive. Therefore, as more and more brain cells die, there is less and less tissue for the medicines to work on. In consequence, medicines for dementia are seldom effective for more than 6-12 months. Sometimes, combining medicines with different mechanisms of action can extend the duration of efficacy.

How do these treatments work?

nThe allopathic medicines act on chemical systems in the brain which are involved in learning and memory; these include the cholinergic and the glutamatergic system. Some of the allopathic medicines are claimed to improve blood flow in the brain, and to stimulate metabolism in the brain. The herbal medicines are claimed to act in much the same way, except that less is known about their actions. This is because, being unpatentable, less money is spent on studying them.

Are all the treatments equally effective?

nWe do not know because few or no studies of good quality have directly compared any two of these medicines. In fact, only donepezil, rivastigmine, galantamine, and memantine have consistently been proven effective. Some but not all studies have found benefits with certain of the other allopathic drugs, and with certain brands of ginkgo and ginseng.

How effective are the Indian herbal medicines?

nThese medicines have been shown to improve learning and memory in animal research. Regrettably, there is little international-standard human research to support the use of these medicines in patients with memory problems.

Do memory pills benefit people  without dementia?

nThe sparse available research suggests that these medicines are ineffective in elderly people without dementia. This is because such people are not sufficiently impaired for the medicines to show detectable benefits. Likewise, students preparing for an examination do not have brain impairments that memory pills can improve. Regrettably, many herbs and formulations are promoted in India for people with subjective memory loss, or for students who face examinations. If at all such medicines help, it is because of a placebo effect, or because certain herbal medicines can reduce anxiety and thereby improve concentration.

What other treatments are there for dementia?

nPatients with vascular dementia may receive medicines which reduce cholesterol and prevent clotting of blood inside arteries in the brain. Patients who lose control of their emotions, and those who experiences confusion, delusions, and hallucinations may require antipsychotic medicines. Medicines are also available to reduce aggression and behavioural disturbances associated with dementia. Experimental treatments are under development; these include a vaccine for Alzheimer's disease!

Is there a take-home message?

nYes. Students should study systematically and all through the year; they will then not need to search for memory pills. And, adults should exercise regularly, eat a healthy diet, keep blood pressure, sugar, and cholesterol levels under control, and stay socially and mentally active; this will reduce the risk of cognitive decline and dementia in old age.

The author is professor and Head, Department of Psychopharmacology, Nimhans and can be contacted at andradec@gmail.com