It is a valuable tool that consist of an assessment that last an average of an hour or two involving the patient, family or significant other and psychiatrist or mental health professional.
 The purpose of a substance abuse intervention is to help the person to recognize the sign of addiction, take the necessary steps to address the addiction,  and provide recommendation and resources to the patient and love one’s to make it a treatable disease. 
 The goal of the intervention is to address the family concerns as well as to help the patient gain insight into the addiction.  The psychiatrist will attempt to motivate the patient to seek the recommended professional assistance and will provide valuable information regarding resources available in the community based on the needs and circumstances of the patient at the time of the intervention.
You or your love one can recognize the presence of an addiction by the presence of many different signs or behaviors  including but not limited to deterioration of personal hygiene, frequent physical complaints, accidents, frequent episodes of anger and irritability, arguments/violent outbursts, extramarital affairs, personality changes, isolation, neglect of children, absenteeism from work, illegal actions, unexplained absences from home, failure to repeatedly meet financial responsibilities, inappropriate spending, neglect of social commitments, poor judgment, defensiveness, frequent job changes or relocation, etc.
The patient may also have deterioration in physical health, unsteady gait, runny nose, nausea, diarrhea, pupils either dilated or constricted, face flushed, slurred speech, inabilities to focus, etc.
An intervention is the simplest most effective technique to be used by family and friends in conjunction with the professional assistance of a mental health professional.