An intervention reorganizes the family (and friends) to extend help in a way that is possible for the impaired person to receive.
An intervention is an orchestrated crisis designed to help a person who needs help to accept it even though he is convinced he doesn’t need it. This kind of denial is usual in the presence of an addiction (to a substance or behavior). It can also appear when a defense system has been reinforced over time — e.g. an elderly person afraid of change and resisting going into assisted living.
The secret of an intervention is Numbers — the concentrated caring energy of a whole group representing significant parts of a subject’s life. A troubled person can easily deflect one concerned person, but a group has unique power to reflect back to the suffering person the goodness and value he had come to doubt. This process is how Betty Ford (wife of the former President) was gently persuaded by her family and friends to enter treatment and begin a new life of recovery, a life which has blossomed for the benefit of many people beyond her own family.