NPD has been thrown around in the news a lot lately. Does that make it any more likely to show up on the social work licensing exam? Hard to say. Exam writers read the news too! Criteria for NPD are:
A pervasive pattern of grandiosity (in fantasy or behavior), need for admiration, and lack of empathy, beginning by early adulthood and present in a variety of contexts, as indicated by five (or more) of the following:
1. Has a grandiose sense of self-importance (e.g., exaggerates achievements and talents, expects to be recognized as superior without commensurate achievements).
2. Is preoccupied with fantasies of unlimited success, power, brilliance, beauty, or ideal love.
3. Believes that he or she is "special" and unique and can only be understood by, or should associate with, other special or high-status people (or institutions).
4. Requires excessive admiration.
5. Has a sense of entitlement (i.e., unreasonable expectations of especially favorable treatment or automatic compliance with his or her expectations).
6. Is interpersonally exploitative (i.e., takes advantage of others to achieve his or her own ends).
7. Lacks empathy: is unwilling to recognize or identify with the feelings and needs of others.
8. Is often envious of others or believes that others are envious of him or her.
9. Shows arrogant, haughty behaviors or attitudes.
And that's it. Simple--and difficult--as that. Narcissistic personality disorder is grouped with antisocial personality disorder, borderline personality disorder, and histrionic personality disorder in Cluster B.
Seasoned social workers can usually assess the presence of a personality disorder pretty quickly, without knowing which PD they're facing. The quick summary you'll hear all the time in the field: "Cluster B." On the exam you have to be more certain--know these criteria and how to distinguish from the other personality disorders and you'll be able to correctly answer without too much difficulty.
For further reading, try the Mayo Clinic's NPD page: http://www.mayoclinic.org/diseases-conditions/narcissistic-personality-disorder/basics/definition/con-20025568 and Wikipedia's pages, linked here: https://en.wikipedia.org/wiki/Cluster_B_personality_disorders
Good luck on the exam!