Global Assessment of Functioning: A number assigned to an individual rating that individual's overall psychological functioning. Not a disorder but rather an easy way for other professionals to see the lowest level the individual was for the past year. An individual can receive a score from 0-100. For example if a person were to receive a score from 61-70 that individual would have some mild symptoms (e.g. depressed mood and mild insomnia) or some difficulty in a social context such as school or work. The lower the score the lower functioning individual. An individual would be hospitalized if they received a score below 50 in most cases. An average individual has a score above 80.
This score will change depending on the situation. For example an average individual going through a crisis will have a much lower GAF score than if that individual was in a normal situation.