Giving frontline health workers worldwide a better tool to diagnose and treat disease is the goal of the World Health Organization as it revises its International Statistical Classification of Diseases and Related Health Problems (ICD), said WHO psychologist Geoffrey Reed, PhD, at APA's 2009 Annual Convention.

The ICD-11—being drafted now and due for publication in 2015—promises to be a more clinically useful tool that will better capture patient conditions and will embrace electronic technology to allow interactive information-sharing. WHO's priorities for the revision call for the system to be global, multilingual, multidisciplinary, transparent and free from commercial input.

All of those factors have the potential to improve care worldwide, which is particularly important for people with serious mental disorders, the majority of whom receive little or no treatment, said Reed.

"Mental disorders contribute more to global disability and disease burden than any other category of non-communicable disease," said Reed. "There's a huge need for services, and people are not getting them."

Currently, the United States is still using the clinical modification of ICD-9, although ICD-10 was approved by the World Health Assembly in 1992. The country is scheduled to implement ICD-10 in 2013, so it's important for psychologists to be familiar with this system, said Reed. (Canada has been using the ICD-10 for years.)

Psychologists are critical to the revision process for the ICD chapter on mental and behavioral disorders, said Reed, senior project officer and managing editor for this part of the ICD revision. Historically, the revision has been dominated by psychiatry, but WHO is committed to involving a wider array of users.

Psychologists have much to contribute both in terms of research and practice insights, and the International Union of Psychological Science is officially represented on the revision steering committee.

As a member of WHO, the United States is required to report mortality and morbidity data to WHO using the ICD. In addition, the Health Insurance Portability and Accountability Act requires health providers to use ICD codes rather than codes from the Diagnostic and Statistical Manual of Mental Disorders (DSM) in all electronic transactions. The ICD-11 will drive future reporting and billing for mental disorders worldwide. In fact, to be used for billing and reporting, new versions of the DSM will need to be compatible with the ICD.

A new emphasis

Clinicians have long argued that both the ICD and the DSM are difficult to use and do not accurately describe patient problems, said Reed. Both systems are extraordinarily complex, with clinicians commonly expected to remember 20 to 35 pieces of information to make one of more than 400 diagnoses. "Neither system captures the presentation of mental disorders in practice settings in a clinically accurate and descriptive manner, and they are not supporting the efficient use of limited treatment resources at the clinical or country level," he explained.

That will change with the ICD-11. The system is intended for daily clinical use and is likely to have fewer diagnostic entities and simpler critieria, said Reed. Researchers are also likely to have more diagnostic options so they can track data according to finer subcategories that are relevant to their work but not necessary for daily clinical work.

Eventually, the data will be integrated into health informatics systems, accessible worldwide. The data will be aggregated at the clinic, facility, system and country level and used for a wide variety of important purposes, said Reed, such as treatment selection, eligibility determination, reimbursement, outcomes and health services evaluation, and the development of health policy. As the revision continues, one priority for psychology should be to develop more international and interdisciplinary networks and collaborations, he said.

"Most people with mental and behavioral disorders simply cannot access appropriate care, in part because there are just not enough services available, but also because mental health problems are not accurately identified," said Reed. "A classification that is usable and useful where people come into contact with a health-care system will improve the identification of those who need mental health services and help to direct them to necessary and appropriate care."