The Global Assessment of Functioning (GAF) is a scoring system that mental health professionals use to assess how well an individual is functioning in their daily lives. This scale was once used to measure the impact of psychiatric illness on a person’s life and daily functional skills and abilities.
The scores range from 0 to 100, with 100 representing superior functioning. Doctors take into consideration how much difficulty a person has in their daily life with social, occupational, school, and psychological functioning before assigning a score.
This scoring system made its first “appearance” in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Publishers released this version in 1980. The DSM features diagnostic criteria for mental disorders. Having the manual allows doctors across the world to use the same symptom set to make diagnoses.
While doctors still use the GAF score, it doesn’t appear in the latest edition of the manual, the DSM-5. The newest edition replaced the GAF score with the World Health Organization Disability Assessment Schedule 2 (WHODAS 2.0).
When a person’s mental illness makes it difficult to function in their everyday life, they need help. This could include counseling services or around the clock medical care. Doctors use a GAF score to determine how much help a person may need due to their illness.
Because the GAF system uses a standard set of criteria, one doctor can tell another doctor a person’s GAF score and they immediately have an idea of how a person’s illness affects them.
There are two main categories of consideration. The first is a person’s level of functioning in daily life. The second is the severity of their mental illness. Doctors can determine a person’s GAF score using several items of information, including:
- talking to the person
- interviewing the person’s family members or caretakers
- reviewing the person’s medical records
- reviewing a person’s police or court records detailing their behavioral history
Once a doctor reviews this information, they review the GAF scoring ranges. While the scores may be numeric, the scoring is still subjective. This means two doctors could possibly assign a person two different GAF scores. However, this ideally this wouldn’t happen.
Examples of the scoring system’s criteria include:
- 100 to 91. Superior functioning with no symptoms that impair functioning.
- 90 to 81. Absent minimal symptoms, such as anxiety before an exam.
- 80 to 71. Slight impairment in work or school with occasional symptoms that are expected reactions to psychological stressors.
- 70 to 61. Mild symptoms, such as mild insomnia or depressed mood or some difficulty in social, occupational, or home situations.
- 60 to 51. Moderate symptoms, such as occasional panic attacks, or some difficulty in building meaningful social relationships.
- 50 to 41. Serious symptoms, such as suicidal thoughts or severe, obsessive rituals. The person could also have severe impairment in work, such as being unable to keep a job.
- 40 to 31. Some impairment in communication, psychosis (loss of touch with reality) or both, or major impairment in school, work, family life, judgment, thinking, or mood.
- 30 to 21. A person experiences frequent delusions or hallucinations or features severely impaired communication or judgment. They’re unable to function in almost all areas, such as staying in bed all day, and have no meaningful relationships.
- 20 to 11. A person is in danger of hurting themselves or others. They may have made suicide attempts, display frequent violent behaviors, or have major impairment in communication, such as muteness or speaking incoherently.
- 10 to 1. A person is in almost constant danger of hurting themselves or others, has made a serious suicidal act with clear expectation of death, or both.
- 0. There’s inadequate information to assess the person.
Doctors have also created a children’s global assessment scale that’s similar to the earlier scale, but it refers more to issues in school or building relationships with classmates.
A GAF score is just one way that doctors can evaluate a person with a mental illness or who has difficulty coping with daily life. Since the DSM-5 has debuted in 2013, the scale has fallen into disuse in favor of the new WHODAS 2.0 scale.
While no psychiatric measurement scale is perfect, doctors have criticized the GAF score because it can fluctuate from day to day. Another criticism is that the GAF doesn’t identify the differences between a mental illness and a medical disorder that causes psychiatric symptoms. The newer scale, the WHODAS 2.0, does.
These and other psychological tools are always evolving to help more people get the help and services they need.