The Global Assessment of Functioning (GAF) score is a single numerical rating that mental health clinicians previously used to measure a patient’s overall level of psychological health. This measure captured a complete picture of an adult’s mental health, assessing psychological, social, and occupational functioning on a continuum of mental health and illness. The GAF scale was listed as Axis V in the multiaxial diagnostic system of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). It served as a standardized way to communicate the severity of a patient’s impairment to other practitioners, insurance companies, and legal entities.
Understanding the GAF Rating Scale
The GAF scale provides a rating from 1 to 100, where higher scores indicate better functioning and lower scores signify more severe impairment. This continuum is divided into ten distinct ranges, each linked to specific descriptive criteria of symptom severity and functional capacity. A score between 91 and 100 represents superior functioning across a wide range of activities with no symptoms, indicating a high level of psychological health.
The mid-range scores reflect increasing levels of difficulty that become more noticeable in daily life. For instance, a score in the 61 to 70 range suggests mild symptoms, such as depressed mood or mild insomnia, or some difficulty in social or occupational functioning, like occasional truancy. A score in the 51 to 60 range indicates moderate symptoms, such as occasional panic attacks, or moderate difficulty in maintaining meaningful relationships or work performance.
Scores falling in the lower ranges signal more serious levels of impairment that often require intensive support. A GAF score between 41 and 50 is assigned when a person exhibits serious symptoms, like suicidal ideation or severe obsessional rituals, or serious impairment in their ability to keep a job or maintain friendships. The lowest range, 1 to 10, is reserved for individuals who pose a persistent danger of severely hurting themselves or others, or who are unable to maintain minimal personal hygiene.
Principles of GAF Assessment
Calculating a GAF score requires the clinician to evaluate two distinct components of the patient’s presentation: the severity of their symptoms and their level of functional impairment. Symptom severity refers to the presence and intensity of psychiatric signs, such as hallucinations, anxiety, or disorganized thought patterns. Functional impairment assesses how well the individual manages real-world activities, including their social life, work, and personal care.
The fundamental rule for assigning the final GAF score is that it must reflect the lower (or worse) of the two areas: symptom severity or functional impairment. This ensures the score represents the maximum severity of the person’s overall difficulty. A patient might have severe symptoms yet maintain a high level of functioning, or conversely, mild symptoms that still cause significant life disruption.
Consider a hypothetical patient experiencing frequent auditory hallucinations, typically associated with a low symptom severity score (31 to 40 range). If this patient is still able to attend college classes and maintain a part-time job (functional impairment rated 61 to 70), the clinician assigns the score based on the more severe symptom presentation, resulting in a score between 31 and 40. Conversely, a person with persistent, mild depressive symptoms (symptom score of 71-80) who has become completely isolated and unable to leave the house (functional score of 31-40) would be assigned the lower score, reflecting the greater functional difficulty.
GAF’s Role in Clinical Practice
Historically, the GAF score was widely used by mental health providers for several practical applications within clinical settings. It served as a quick, standardized way to track patient progress over time, allowing clinicians to note whether the score increased or decreased following the implementation of a treatment plan. The single numerical score was often a factor in determining the level of care needed, facilitating communication between different healthcare providers and institutions.
The score also played a significant role in administrative and legal contexts, particularly for insurance reimbursement and disability evaluations. Organizations like the Social Security Administration and the Veterans Benefits Administration often considered GAF scores as part of the evidence to determine eligibility for benefits related to psychiatric disorders. Since the score provided a concise measure of global impairment, it was a convenient tool for non-clinical decision-makers.
The GAF score was removed from the DSM-5, the latest edition of the diagnostic manual, in favor of a more comprehensive assessment tool. The American Psychiatric Association recognized that the GAF conflated symptoms and functioning, leading to reliability concerns among different raters. The manual replaced it with the World Health Organization Disability Assessment Schedule (WHODAS 2.0), which offers a more detailed, multi-domain assessment of disability. However, the GAF score continues to appear in existing medical records and is still used in some government and legal settings that have not yet fully transitioned.