The Diagnostic and Statistical Manual (DSM) is used by clinicians and psychiatrists around the world to diagnose mental disorders and psychiatric illnesses. Published by the American Psychiatric Association (APA), it was first printed in 1952. It covers all categories of mental health disorders for both adults and children.
As you might expect, the DSM has been through a number of revisions in its history. The newest version of the DSM came out in May 2013 with many changes incorporated to better characterise symptoms and behaviours in people living with complex mental illness.
Research into mental health increasingly focuses on biology, genetics and neuroscience. The latest DSM acknowledges this by re-ordering disorders according to what age they're most likely to appear and recognising how cultural factors, such as gender and sexuality, can affect diagnosis.
It also includes a new section with information on disorders that require additional research before they can be incorporated into the official diagnoses and diagnostic criteria.
APA's goal in developing the DSM is to provide an evidence-based manual for clinicians and psychiatrists to use when assessing and diagnosing psychiatric illnesses. The DSM contains descriptions, symptoms and other criteria for diagnosis, and is widely used in research and academic fields.
However, while it's considered the most authoritative guide available for diagnosing mental disorders, it has attracted its fair share of criticism over the years.
Some people question the reliability of psychiatric diagnoses when mental disorders are so complex – and circumstantial. The DSM is designed to group similar types of diagnoses together, and opinions differ as to which particular disorders should be grouped together or even included.
The latest edition follows a 'dimensional' approach, reflecting a new understanding that the lines between many disorder categories blur over the life span and the symptoms attributed to a single disorder may also appear in other disorders, just with different levels of severity.
In other words, it accepts that many mental disorders and psychiatric illnesses are grounded in the same 'dimension' or system, and that's why so many people have conditions that overlap or intersect with each other.
Clinicians and psychiatrists are the primary users of the DSM. Some see it as a guide, others treat it as a 'bible'.
The DSM also provides the untrained and clinically inexperienced with a starting point for exploring the underlying nature and structure of mental health problems.
It is sometimes used by insurance companies who require diagnoses made using specific criteria to match to reimbursement categories.
Over the years, the DSM has been revised and reviewed multiple times. Findings from research prompt many of the changes - but incorporating feedback from mental health professionals is also part of the process.
Decisions to include a new disorder or revise an existing diagnosis are based on careful assessment of the scientific advances in research underlying the disorder as well as the combined knowledge of experts in the field. The DSM's diagnostic criteria are formulated by expert committees and then tested in studies to see how well they define distinct groups of people.
Each revision of the DSM takes many years to complete due to how comprehensive the process is. The research base of mental disorders evolves at different rates for different disorders and evidence base for diagnostic criteria changes over time so updates aren't regularly scheduled but they are ongoing.
A commitment to more frequent updating was also made apparent in the latest version with a switch to an Arabic numeral in the manual's name.
Last year, APA created an online portal for the public to submit suggested changes to the DSM-5, which means anyone can make a case for additions, deletions or modifications.
This online portal offers a fantastic opportunity for clinicians, scholars and members of the public to have their say about mental health classifications and diagnostic criteria.