At the turn of the millennium, the American Psychiatric Association (APA) began a massive undertaking to expand the scientific basis for psychiatric diagnoses with an update to their Diagnostic and Statistical Manual of Mental Disorders (DSM). This vital publication hasn’t had a systematic evaluation or overhaul since DSM-IV was released in the mid-1990s, aside from a minor text revision released in 2000 (DSM-IV-TR). Now, following more than a decade’s worth of work and a reported $25 million in expenditures, revisions to the DSM are finalized and ready to hit the market in May of this year. What changes can you expect when DSM-5 comes to a bookshelf near you?

The most immediately obvious change is the sheer weight of the volume. Like the Harry Potter or Twilight book series, the DSM has ballooned in size with every edition. The current manual is 943 pages, hefty in comparison to the svelte 130 pages of the series’ maiden version. DSM-5 boasts added diagnostic entities, expanded scientific justifications, and an extensive list of proposed research initiatives. True to its size, the book comes with a whopping price tag. Although DSM-IV and DSM-IV-TR were released at a cost of $65 and $84 respectively, this edition has hit the market for preorder at a listing price of $199 in hardcover and $149 in paperback.

Among the more substantive changes, the content has been reorganized to reflect a “lifespan approach,” according to the APA, with disorders typically diagnosed in childhood appearing earlier in the manual and disorders more often seen in later adulthood (such as neurocognitive disorders) appearing toward the end.

Of the existing diagnoses, autism will probably get the biggest overhaul, with autism, Asperger’s disorder, pervasive developmental disorder, and childhood disintegrative disorder all consolidated into an overarching classification of autism spectrum disorder. Similarly, substance abuse and dependence criteria will be subsumed into substance use disorder (specified by the substance, including alcohol, opioids, caffeine, and tobacco).

There are new disorders, including compulsive hoarding and exoriation (skin-picking), added to a section on obsessive-compulsive and related disorders. Binge eating disorder will join the list of eating disorders. Disruptive mood dysregulation disorder has been added in an effort to stem the rapid growth of bipolar disorder diagnoses in children. The new classification is for children between 6 and 18 years of age with recurrent irritability, reactivity, and severe mood fluctuations.

One thing about the manual won’t change, however. In December, the APA Board of Trustees overruled the proposed changes to personality disorder criteria and diagnoses. Due to excessive complexity and lack of available scientific support, the alternative personality proposal will be relegated to a section of the manual dedicated to areas for further research investigation. Instead, DSM-5 will retain the same personality disorder system as currently provided in DSM-IV-TR.

How the DSM changes will affect clinical practice, training, research, and social policies has yet to be determined. Allen Frances, chair of the DSM-IV Task Force and a vocal critic of the new manual, has publicly declared, “The DSM-5 debacle is a sad moment in the history of psychiatry. Patients deserve better, and so does the profession of psychiatry.” Not surprisingly, the APA paints a different picture. In a released statement, the APA’s current president, Dilip Jeste, said, “We developed DSM-5 by utilizing the best experts in the field and extensive reviews of the scientific literature and original research, and we have produced a manual that best represents the current science and will be useful to clinicians and the patients they serve.”