Résumé : Helping and caring for patients suffering from Alzheimer's disease and related dementias are mostly provided by the patient's entourage at his home. The non-professional caregivers are described under the name of « natural or informal help ». Although more and more studies are coming out concerning the notion of caregiver burden, very few deal with the consequences upon the intrapsychic experience of the person sharing the life of the demented patient. Even fewer studies are devoted to specific aspects of the conjugal bond at the center of dementia. How will time and old age affect this bond, both on the objectal and narcissistic levels? What can explain the fact that, for some, the conjugal bond becomes pathological? What will happen when one adds dementia to the equation? In a situation of aging conjugopathy, where one member of the couple develops a neurodegenerative disease, what allows some caregivers to take advantage of new psychic investments whereas others fall apart? The propensity to experience satisfactions in the caregiving situation seems to depend, among other things, upon personality traits, as illustrated by one clinical case.