Do you need to know the entire DSM-5? You do not. While knowing the Code of Ethics up and down back to front may be wise, spending your precious spare minutes and hours getting into the DSM-5 weeds is really a waste of time. Just get a copy of the nice, compact Desk Reference (aka Desk Reference to the Diagnostic Criteria from DSM-5). They might've called it the Exam Reference... It's got just about everything you'll need for most diagnostic questions on the test. That is, the criteria for each disorder.
Speaking of...let's flip open a page and learn some criteria. Something you may not know from every day social work. Let's see...Personality Disorders...Cluster C...here we go: Avoidant Personality Disorder. What is it? The DSM-5 says it's:
A pervasive pattern of social inhibition, feelings of inadequacy, and hypersensitivity to negative evaluation, beginning by early adulthood and present in a variety of contexts...
Simple enough. Or is it. This could get confusing on the exam. Just picture a vignette that more-or-less matches what's described above. And then imagine facing these choices for BEST or MOST likely diagnosis:
A) Avoidant Personality Disorder
B) Major Depressive Disorder
C) Social Anxiety Disorder
D) Narcissistic Personality Disorder
Okay, you can rule out NPD. And after some wrestling, maybe MDD as well. But how do you make the pick between APD and SAD?
Let's continue in the DSM:
...as indicated by four (or more) of the following:
1. Avoids occupational activities that involve significant interpersonal contact because of fears of criticism, disapproval, or rejection.
2. Is unwilling to get involved with people unless certain of being liked.
3. Shows restraint within intimate relationships because of the fear of being shamed or ridiculed.
There's more, but a meaningful difference with Social Anxiety Disorder has emerged. SAD has the fear of ridicule and some other elements of APD, but it doesn't have them everywhere, all the time. That's the difference between a disorder and a personality disorder. If you're alert to that essential difference when facing a tricky vignette on the social work licensing exam, you're good to go. Enjoy breezing that question and the rest of the exam. Congratulations in advance on your new license!