The American Psychiatric Association released a new edition of its Diagnostic and Statistical Manual of Mental Disorders, known as the DSM-5, on May 18. Although the manual is primarily used by psychiatrists and other mental health professionals in diagnosing patients, its influence extends to the courts and the development of employment law as well. The DSM-5 will surely affect employment law profoundly, but it may well do so in some disparate and unpredictable ways.

The DSM-5 is likely to expand the number of conditions covered by the Americans with Disabilities Act (ADA). Although the DSM-5 cautions that the assignment of a diagnosis does not imply a specific level of impairment or disability, this distinction has little practical meaning given the enactment of the ADA Amendments Act in 2008, in which Congress decreed that the definition of "disability" for purposes of the ADA is to be construed broadly in favor of coverage. The Equal Employment Opportunity Commission's regulations issued under that law even decreed that certain psychiatric disorders, including post-traumatic stress disorder (PTSD), major depressive disorder and bipolar disorder, will almost always qualify as disabilities.

The DSM-5 adds several new diagnoses that employers will find vexing. One is "social (pragmatic) communication disorder," which describes people whose communication skills are impaired but who do not qualify for an autism diagnosis. It applies to people with "persistent difficulties in the social use of verbal and nonverbal communications" that limit social relationships or occupational performance. While typically diagnosed in childhood, it can continue into adulthood. Employees previously thought to be merely shy or socially awkward may qualify for this new diagnosis.

Another new diagnosis is "binge-eating disorder," a condition characterized primarily by eating a large amount of food in a short time at least once per week for three months. The DSM-5 notes that while most overweight people do not engage in recurrent binge eating, binge-eating disorder is "reliably associated with overweight and obesity." Thus, this diagnosis makes it more likely that obesity (at least when precipitated by binge eating) might finally qualify as a disability under the ADA.

Yet another new diagnosis is "mild neurocognitive disorder." This describes a modest decline in learning, attention or memory not associated with another mental disorder and that does not interfere with the person's ability to live independently, but which may require "greater effort, compensatory strategies or accommodation." This can probably be found in almost anyone over the age of 50. While accommodation for the effects of aging is not required under the Age Discrimination in Employment Act, this new diagnosis may lead to requests for accommodation by older workers for the ordinary effects of aging.

The DSM-5 also adds premenstrual dysphoric disorder as a formal diagnosis. This diagnosis requires the occurrence of symptoms such as mood swings, increased interpersonal conflicts, anxiety or tension, overeating or food cravings, a sense of being overwhelmed, or weight gain, "bloating" or breast tenderness in the week prior to the start of the menstrual cycle.

The DSM-5 also makes it easier to qualify for some diagnoses. For example, the "bereavement exclusion" has been removed from the definition of major depressive disorder. Under earlier editions of the DSM, major depression could not be diagnosed for ordinary bereavement symptoms lasting no more than two months. Under the DSM-5, a person having symptoms of depression for longer than two weeks may qualify for a diagnosis of major depression even if those symptoms are the result of bereavement. Employees, therefore, could seek more lengthy bereavement leaves than are currently available following the death of a family member or close friend.

The DSM-5 additionally broadens the diagnostic criteria for PTSD in two key ways. One, it permits a PTSD diagnosis where the person merely learns about a traumatic event, versus the prior requirement that the event actually be witnessed or experienced. Two, it eliminates the prior requirement that the person experience fear, helplessness or horror at the time of the traumatic event. These changes may increase the number of employees who will qualify for a PTSD diagnosis.

Finally, the DSM-5 does not treat personality disorders separately from other mental disorders, as did its predecessors. These long-term conditions include antisocial, borderline and narcissistic varieties, in which a person exhibits disruptive behavior and often has extreme difficulty relating to others. Previous versions of the manual did focus extensively on the diagnosis and treatment of these disorders, but the DSM-5's including them among other mental disorders will likely increase the frequency of their diagnosis. Antisocial personality disorder is characterized by manipulativeness, deceitfulness, lack of empathy and irresponsibility. Borderline personality disorder is marked by severe emotional instability and impulsive behavior. Narcissistic personality disorder is characterized by excessive need for approval, grandiosity, a sense of entitlement and lack of empathy.

While the DSM-5 may increase the number of ADA claims, two of its changes may be beneficial to employers facing claims for mental damages in employment litigation.

First, earlier editions of the DSM utilized a "Global Assessment of Functioning" (GAF), scored on a 0-100 scale. The GAF was often misused in expert testimony in employment lawsuits, as a mental health expert would testify that before being fired, the plaintiff had a GAF of 90 (blissfully happy), and after being fired, his GAF plummeted to somewhere around 40 (barely functioning). Most experts just assigned a GAF score arbitrarily, but juries sometimes found it a meaningful measure of how badly a plaintiff "suffered" at the hands of the defendant. The DSM-5 eliminates the GAF, so this sort of testimony will no longer be possible.

Second, the DSM-5 tightens up the definition of PTSD a bit in a way that is helpful to employers. It requires that the traumatic event involve exposure to "actual or threatened death, serious injury or sexual violence" versus "actual or threatened death or serious injury, or a threat to the physical integrity of self or others" as required in the previous DSM. The latter definition led to attempts by plaintiffs to attribute PTSD to sexual harassment, job loss, discrimination and common workplace conflicts. Except where a physical or sexual assault occurs, a PTSD diagnosis cannot validly be given under the DSM-5 for unpleasant events occurring at work. In fact, the DSM-5 places such phenomena as sexual harassment, unemployment, job stress and conflicts with bosses or co-workers in a category called "occupational problems" that may cause a person to seek counseling or therapy but that do not warrant a diagnosis of a mental disorder.

Here are four things corporate counsel should do in light of the DSM-5:

• Ensure that employees who handle accommodation requests are well trained on the definition of disability and what must be done to accommodate disabled employees and applicants.

• Carefully document the employee's work restrictions and the interactive process undertaken to determine how those restrictions might be accommodated. Focus on the restrictions, not the diagnosis, and remember that accommodations are required only if they will enable the employee to perform the job, not merely to make the workplace more agreeable.

• Where accommodations are sought based on diagnoses or work restrictions that are uncertain or dubious, exercise the employer's right to obtain a second opinion from a physician of the company's choosing.

• Use the DSM-5's changes in the definition of PTSD proactively to refute invalid PTSD diagnoses in litigation and in the ADA accommodation process.

Many individual cases will have to play out before the DSM-5 comes into clearer focus. But if some of the changes may prove vexatious for corporate counsel, the tightening of certain diagnoses offers some silver linings among the dark clouds ahead. By understanding as fully as possible both the pros and cons of the new manual, corporate counsel can ensure that their companies aren't driven up the wall by the changes the DSM-5 will bring in the employment arena.

James J. McDonald Jr. is managing partner of the Irvine, Calif., office of Fisher & Phillips. This article first appeared in Corporate Counsel, a Legal affiliate based in New York.