The WHO has just released to the world the new International Classification of Diseases, the ICD-11. WHO has the unique mandate of working with 194 Member States around the world to achieve better health for everyone, everywhere, and the first essential step towards doing so is a classification system that can be used by all nations to define and describe the universe of diseases, disorders, injuries and other related health conditions. Welcome ICD-11!
Mental, behavioural and neurodevelopmental disorders are housed in chapter 6. Comprising a decade of work led by Geoffrey M. Reed PhD, this new chapter represents the culmination of the efforts and contributions of thousands of individuals, including researchers, clinicians and service users from around the world.
Why should I care and what’s new?
Classification is the essential core of all of our health research, policy and care. The ICD-11 serves as the bible of classification. If a condition, disease or disorder gets a name, it gets a code, and then it becomes part of the health system. This means that health policies can provide coverage, health providers can be trained in the care of the condition, and health systems can track trends and statistics globally. You know when you leave the doctor’s office with an encounter form covered with codes? Those are ICD codes. You know when you read in the paper that depression and suicide are on the rise globally? That is because the ICD provides a common language and system for describing and documenting such trends.
Transgender is no longer a mental disorder. The ICD-11 now includes a new chapter on sexual health. This has made it possible to formally recategorize certain conditions which were formerly listed as mental health conditions. Of particular import is the move of gender incongruence – the ICD term for people whose gender identity is different from the gender they were assigned at birth – out of the mental disorders chapter and into the sexual health chapter. The change reflects important advances in understanding sexual health and aims to improve social acceptance of transgender people, while still making important health resources available.
Gaming disorder is now a mental disorder. Added to the Addictive behaviour subgroup, Previously, only gambling disorder was included as a behavioural addiction warranting a diagnosis. It is characterized by impaired control and limit setting over gaming, increasing priority given to gaming over other activities to the extent that gaming takes precedence over other interests and daily activities, and continuation of gaming despite the occurrence of negative consequences. Significant psychosocial impairments must be present and a duration criterion of 12 months applies unless the symptoms are very severe, in which case the duration criterion may be shortened. Although most parents are frustrated by their kids’ obsession with electronic games at some point, the threshold for gaming disorder rules out this normative experience and is intended to identify those whose lives are severely impacted.
Post-Traumatic Stress Disorder (PTSD) changes in important ways. PTSD has been in previous versions of the ICD. The big change is that the concept of Post-Traumatic Stress Disorder (PTSD) is now narrower. PTSD requires the presence of three core symptoms: re-experiencing, avoidance, and perceptions of heightened current threat. In addition, the ICD-11 has introduced a new complex PTSD category. In addition to the full clinical experience of PTSD, individuals with complex PTSD also report problems regulating mood, persistent problems in self-worth and self-esteem, and difficulties in sustaining relationships and feeling close to others.
Avoidant Restrictive Food Intake Disorder is a new and different kind of eating disorder. Having spent much of my research career focused on women’s health and eating disorders, I had the privilege of working on the Expert Consultation Group for the feeding and eating disorders of ICD-11. One of the significant additions we proposed was the introduction of Avoidant-Restrictive Food Intake Disorder (ARFID). At home, you might call this “picky eating.” It is picky eating taken to the extreme. Usually starting in childhood, ARFID is characterized by abnormal eating that results in the intake of an insufficient quantity or variety of food to meet adequate energy or nutritional requirements. The pattern of restricted eating causes significant weight loss or failure to gain weight as expected in childhood or pregnancy, clinically significant nutritional deficiencies, and dependence on oral nutritional supplements. Unlike other eating disorders, in the case of ARFID, the eating pattern is not driven by concerns about body weight or shape.
The ICD-11 marks the first update of this global classification system since 1990. There are many other changes in the mental, behavioural and neurodevelopmental disorders chapter of the ICD-11 that reflect our increased understanding of mental disorders. You can learn more here.
Our WHO Collaborating Centre at Columbia University Department of Psychiatry has contributed in multiple ways to this work, including serving as the Data Coordinating Center for the many field studies that were conducted to test new proposals. This work was guided by the principle of improving care in the real world and will help us realize the greater WHO aspiration of better health for everyone, everywhere. Onward!