The International Classification of Diseases (ICD-11) was released last month. That's a big deal for a number of reasons, not least of which is that it is the first ICD revision in over two decades. It's not very often that ICD gets an overhaul.

Source: Thorkild Tylleskar

Psychologists and other mental health professionals are familiar with the (the current version being the DSM-5), but are often less acquainted with the ICD. The two manuals are distinct but related. While the DSM is basically a product of American , the ICD is broader both in authorship and scope. The ICD is an international undertaking written by the World Health Organization (WHO). It classifies not just mental disorders, but all recognized diseases and medical conditions.

Most of the initial news coverage of the ICD-11's release focused on its inclusion of a new mental disorder called gaming disorder, which it characterizes as involving “a pattern of persistent or recurrent gaming behaviour (‘digital gaming’ or ‘video-gaming’).” understandably received a lot of due to ongoing debate over whether too much time playing video games is a disorder rather than merely a vice. However, while gaming disorder has received an extraordinary amount of news coverage, many other significant changes to the mental disorders section of ICD-11 have yet to receive sufficient attention. Below a few of the many noteworthy changes are highlighted.

Compulsive Sexual Behavior Disorder Was Added

According to the ICD-11, compulsive sexual behavior disorder is "characterized by a persistent pattern of failure to control intense, repetitive sexual impulses or urges resulting in repetitive sexual behaviour." This new diagnostic category calls to mind the contentious notion of " ." Perhaps to circumvent this, the ICD-11 has classified compulsive sexual behavior disorder as an impulse control disorder rather than an addictive disorder. Still, including compulsive sexual behavior in the ICD-11 is not without controversy. Critics worry that this new diagnosis inappropriately pathologizes people who have a strong drive or act out sexually, but supporters of adding compulsive sexual disorder to ICD-11 probably see its inclusion as long overdue.

Incongruence Is No Longer a Mental Disorder

The ICD-11 uses the term gender incongruence instead of the DSM-5 term or the now-out-of-favor ICD-10 term transsexualism. Beyond the name change, the huge shift in ICD-11 is that gender incongruence is no longer classified as a mental disorder. However, it's important to realize that gender incongruence has not been removed from the ICD-11. It has simply been relocated from the mental disorders section to a new section on conditions related to sexual health that also includes sexual dysfunctions and sexual pain disorders. The idea is to destigmatize gender incongruence and highlight it as a strictly medical, rather than psychological, issue. Of course, debate continues over whether gender incongruence/dysphoria should be a diagnosable condition at all—but with access to therapies and surgery typically requiring a gender incongruence/dysphoria diagnosis, transgender advocacy groups such as the World Professional Association for Transgender Health (WPATH) support maintaining such a diagnosis in ICD-11, especially given its reclassification as a condition related to sexual health.

is No Longer a Mental Disorder, but Prolonged and Complex Are

* Acute Stress

ICD-11 no longer considers acute stress—the brief experience of intense psychological distress following exposure to a event—to be a mental disorder. In other words, acute has been removed from the mental disorders section of ICD-11. Instead, it has been reclassified as a reaction to trauma and placed in ICD-11's section on factors influencing health. This is in direct contrast to the DSM-5, which continues to classify acute stress as a disorder. The ICD-11's intention is to acknowledge but depathologize brief periods of emotional upset in response to trauma. In another interesting difference, the ICD-11 says that acute stress should only be diagnosed when the response lasts a few minutes to a few days after the traumatic event, while the DSM-5 says acute stress can be diagnosed whenever symptoms last up to a month. Thus, more people likely qualify for the DSM-5 than ICD-11 diagnosis—and those who do are considered mentally disordered according to DSM-5, but not ICD-11.

* Prolonged Grief

In addition to declassifying acute stress, the ICD-11 has also added prolonged grief disorder as an official diagnosis. Prolonged grief is diagnosed in people who have difficulty getting over the loss of a loved one; their grief lasts well-beyond what most others would consider acceptable. As with compulsive sexual behavior disorder, critics worry that adding prolonged grief to ICD-11 runs the risk of pathologizing variations in the grieving process and unreasonably insists that there is a "right" amount of time to grieve. Others, however, likely welcome seeing this disorder added to ICD-11, especially after the DSM-5 opted to list it as a proposed disorder requiring further study.

* Complex PTSD

The ICD-11 also narrowed the definition of posttraumatic stress disorder (PTSD) and supplemented it by adding another new diagnosis, complex PTSD. Thus, PTSD is now restricted to three symptoms: re-experiencing the trauma, avoiding reminders of the trauma, and experiencing a heightened sense of threat and arousal. By comparison, the new complex PTSD diagnosis is broader. It is comprised of all three symptoms of PTSD, but also includes difficulty regulating emotion; feelings of , , or failure; and conflictual interpersonal relationships. The intent is to distinguish patients whose responses are focused mainly on the trauma itself from those whose difficulties ripple more widely through their lives.

Have Been Totally Overhauled

Despite being popular with the general public (if the spate of self-help books available on Amazon is any indication), the disorder sections of both the ICD and DSM have long been problematic, both conceptually and scientifically. The major scientific problem is that, although descriptively vivid, clinicians can't reliably distinguish the personality disorder categories from one another in practice. Thus, the long taken-for-granted assumption that one's supposedly disfigured personality can be distinguished as "borderline," " ," "dependent," "avoidant," or " " is scientifically suspect. Rather than relying on these long-maintained but scientifically problematic categories, researchers have argued that assessing personality disorders should be done by mapping people along various personality dimensions. The DSM-5 took tentative steps in this direction, but its proposed hybrid trait model was an odd compromise that retained some traditional personality disorder categories while also incorporating dimensional assessment measures of personality. The resulting DSM-5 proposal was deemed by some to be overly complicated. It was ultimately not officially adopted, but instead relegated to a section of the DSM-5 containing proposals needing further study. The ICD-11, by comparison, has gone all-in on a totally overhauled personality disorders section. The old categories (borderline, antisocial, dependent, avoidant, etc.) have been completely jettisoned. In their place is one diagnosis—"personality disorder"—which is diagnosed as mild, moderate, or severe after assessing personality along six trait domains. This is a radical departure. Given many people's strong attachments to the familiar (if scientifically questionable) personality disorder diagnoses that have long been in circulation, only time will tell whether clinicians and patients alike will get on board with the new ICD-11 approach.

ADHD Has Finally Been Added

That's right: Until ICD-11, there was no ADHD diagnosis in the ICD. The ICD-11 marks the first time that attention-deficit hyperactivity disorder (ADHD) is being included in the manual. In fact, the ICD-10 was skeptical (one might even say hostile) to ADHD as a diagnosis, noting that “in recent years the use of the diagnostic term ‘ ’ ... has been promoted. It has not been used here because it implies a knowledge of psychological processes that is not yet available.” Therefore, the ICD-11's inclusion of this diagnosis marks a significant shift. As rates of ADHD diagnosis are far greater in the United States (where the DSM tends to dwarf the influence of ICD), it will be worth following whether (and how quickly) ADHD rates will rise in countries that have historically relied on the ICD over the DSM.

New Diagnostic Codes

One of the things that confuses clinicians and clients alike is diagnostic codes, the unique alphanumeric tags assigned to each condition in the ICD. The confusion comes in because diagnostic codes are appropriated by the DSM and must be used, at least in the United States, when health professionals submit insurance claims. However, these codes don't come from the DSM. They come from the ICD. Like its recent predecessors, the ICD-11 has introduced new diagnostic codes. Although it may take several years for most WHO-member countries to adopt these new codes (the U.S. only switched from ICD-9 to ICD-10 codes a few years ago, even though the ICD-9 is two decades old), eventually they will likely be adopted around the world.