Eventually, a doctor identified the problem as Alzheimer's disease, a slow deterioration of mental faculties.

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Compared with the group taking placebo, memantine-treated patients had less deterioration in mental function over the 28 weeks.

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He says a longevity-gene drug, shielding patients simultaneously from mental deterioration, heart disease and stroke, could be ready in less than a decade.

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The film is polished and menacing in its own way, as if her brother were trying to produce a film about his own terrifying mental deterioration.

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Given his history and a deterioration in his mental health following a period in detention, they say there is also concern that restraint techniques will be used on him by security guards accompanying him on a deportation flight.

BBC: High Court challenge over restraint methods