Alzheimer's disease (AD) is a dementia in which symptoms include cognitive impairment and also behaviour and psychological disorders. A study on the family's responses to the AD of a relative, requires envisaging several points of view. a) The family's burden. The caregiver who is generally a spouse, a daughter or a daughter-in-law has to perform difficult tasks. Caring for a patient with AD the caregiver faces a loss of role and reference. The patient's child is often playing the role of parent of the parent. Dementia caregiving exposes to high levels of stress and has psychiatric and physical effects on the caregiver, who is likely to suffer from anxiety, depression, alcoholism, and have an increased risk of mortality. Institutionalisation is a step of critical importance in AD care; the decision has to be made by the family, at the right time; b) The family's responses to AD symptoms. The family has to bear the AD symptoms: cognitive symptoms and above all, behavioural and psychological symptoms. The family senses the diagnosis when the first disorders appear in daily life. Then a large part of the family's history is lost, as the patient becomes unable to talk about the present and the past experience. In AD, the psychological disorders are: depression, anxiety, psychotic disorders and delirium. And in several psychotic disorders, the family may be involved: hallucinations, delusions particularly with ideas of theft, abandonment, jealousy or misidentification. But the most difficult problems are those of behavioural disorders; the family has to face agitation, aggressiveness, apathy, eating disorders, sleeping disturbances, sphincter disorders. The family's responses may be: denial, overprotection, mothering and hyperactivity in caregiving; c) The relationships with the geriatric institution. They are not always peaceful. Conflicts among patient, family and institution may occur, when the family resents guilt and ambivalence about institutionalisation. A former family caregiver may compete with the institution, because he feels deprived of the caregiving role. So, professional caregivers and geriatricians have to propose a therapeutic plan in which family caregivers are implicated; d) The family-patient pathological relationships. The relationships between family and patient may be pathological, due to the caregiver's psychological pathology. The caregiver may suffer from psychiatric or personality disorders, worsened by the relative's AD. Sometimes, abuse by the family is a danger for the patient; e) The support to the family. Before institutionalisation, family caregiving must be helped and supported by professional caregivers and geriatricians. Some treatments reduce behavioural disorders: cognitive enhancement medication or psychotropic medication. But the most important help is provided by professional care at home, re-education, psychotherapies and, if possible, treatment in a day care centre. In practice, american medical associations have tried to design strategies (with guidelines) to support the family caregiver. After institutionalisation, the family must also be supported, so as to keep a pleasant relationship with the relative. The end-of-life and the death are especially difficult, because the feelings of a person with dementia remain partly misunderstood. And the bereavement of an institutionalised patient seems to be more painful than the bereavement after a long and stressful period of family caregiving.