Troubling effects: Former US president Ronald Reagan died after a decade-long battle with Alzheimer?s . AFP

It happened without warning, early one day last summer as they prepared to go out. Gloria Rapport?s husband raised his arm to her, fist poised. ?He was very close to striking me,? she said. What had provoked him? ?Nothing, I asked him to get in the car.?

Rapport?s husband, Richard, 71, has Alzheimer?s disease. His forgetfulness and confusion began about nine years ago, not long after they married. More recently, emotional troubles have loomed. Anxiety came first: He suddenly feared being left alone in the house. Anger followed.

The man she had always known to be kind and gentle could in an instant turn ?cunning, nasty, aggressive, menacing,? she said.

?The behavioural changes I?ve seen are absolutely frightening,? she said. ?I understand now why so many families institutionalise someone, because I was afraid of him.? Though memory loss is the best-known Alzheimer?s symptom, the disease can also cause psychiatric problems that lead to profound changes in personality, mood and behaviour. People who were happy and good-natured for most of their lives suddenly become fearful, depressed, deluded or angry, sometimes even violent. Many families hide it, and perhaps as a result, psychiatric problems were long thought to affect only a minority of people with Alzheimer?s disease or other types of dementia.

Only recently has it become clear that emotional and behavioural troubles are nearly universal among people with Alzheimer?s disease, and the problems are often intractable and more upsetting to families than the mental slowing. Depression and apathy are the most common psychiatric symptoms. But agitated, aggressive and psychotic behaviours are a leading reason that Alzheimer?s patients are put into nursing homes. (The other is incontinence.)

?They are extraordinarily distressing and wearing on caregivers,? said Dr Constantine Lyketsos, a psychiatrist and Alzheimer?s expert at the Johns Hopkins. He said that doctors had become increasingly aware that elderly people who suddenly showed signs of mental illness might actually have Alzheimer?s disease, though in the past they might have been given a diagnosis like ?late-life psychosis,? depression or nervous breakdown.

Rapport said: ?Most families won?t talk about it. I equate this disease to how leprosy used to be. We?ve lost good friends, and we have family members who won?t have anything to do with us. I think they?re afraid of it, and there?s a real stigma that the person is crazy. I think it?s why a lot of families hide people away who have it.?

The symptoms distress not just families, but the patients themselves. ?If your moods are labile or you get anxious and scared, there?s a fair bit of suffering that goes with that,? Lyketsos said. ?If you have visions, or develop ideas that people are trying to steal from you or hurt you, there?s a fair bit of suffering.?

The emotional disorders can be difficult or impossible to treat. There is no drug specifically approved for psychiatric problems in Alzheimer?s patients, so doctors try to treat the symptoms, using drugs meant for other illnesses. They prescribe a wide array of medicines, including antidepressants, anti-psychotics used to treat schizophrenia, and stimulants and drugs approved for anxiety, epilepsy and memory impairment. Sometimes the drugs seem to work; sometimes they do not.

Dr Lon Schneider, a psychiatrist who studies and treats Alzheimer?s disease at the University of Southern California, said: ?Whenever you see a long list of drugs of different classes, you know there?s no good treatment. You get a high degree of uncertainty, and companies hyping their anti-psychotics.?

Overall, Lyketsos said, the effects of the drugs are moderate. But depression seemed to be the most treatable symptom, and could be eased in half to two-thirds of Alzheimer?s patients with drugs like Prozac, which enhance brain levels of the chemical serotonin.

But some psychiatric drugs can have troubling side effects, particularly anti-psychotics, whi-ch may increase the risk of str-oke, diabetes, weight gain, high cholesterol, sleepiness and Par-kinson?s-like movement disorders. There is ?substantial and increasing controversy? about the use of anti-psychotics and other drugs to treat behavioural problems in dementia, Schneider said.

Meanwhile, behaviour therapy and activity programmes at adult day-care centres may work at least as well as drugs in some patients, and families are urged to try them first. Teaching relatives and the nursing home staff what to expect from a person with dementia and how to avoid confrontations can help to keep the peace. ?There?s a tendency for us to want to correct people who are demented,? Schneider said. ?You don?t do that.?

Researchers think the psychiatric symptoms result in part from brain damage, as the disease eats away at nerve centres that re-gulate mood, perception and the ability to control impulses. But some problems may also arise from patients? anguish and frustration over their increasing confusion and inability to function.

Apathy, depression, irritability, sleep disturbances, agitation and aggression are common. Anxiety, delusions, paranoia and hallucinations may also occur, as well as disinhibition, or loss of impulse control. (NYTNS)