I have several perfectionists near me. I would say they are not mentally healthy in this aspect. When you think perfectionist, you might think keeping things tidy. It goes far beyond that. It is a total lack of greyscale. Either things are perfect (never), or they are really bad (pretty much always). This shines through on almost every level in their lives.

You could claim OCPD but I don't think it covers their behaviors.

Wiki mentions symptoms as being a workaholic and always miserable. This fits to some degree. Also mentions things as always only right or wrong, might fit a little as well.

According to Wiki, at least four of these must be present:

Is preoccupied with details, rules, lists, order, organization, or schedules to the extent that the major point of the activity is lost.
Shows perfectionism that interferes with task completion (e.g., is unable to complete a project because his or her own overly strict standards are not met).
Is excessively devoted to work and productivity to the exclusion of leisure activities and friendships (not accounted for by obvious economic necessity).
Is overconscientious, scrupulous, and inflexible about matters of morality, ethics, or values (not accounted for by cultural or religious identification).
Is unable to discard worn-out or worthless objects even when they have no sentimental value.
Is reluctant to delegate tasks or to work with others unless they submit to exactly his or her way of doing things.
Adopts a miserly spending style toward both self and others; money is viewed as something to be hoarded for future catastrophes.
Shows rigidity and stubbornness.

None of them is a list maker.
Sometimes they meet their standards (at a high cost), sometimes not.
Some are devoted to work.
Some are having strict moral values.
None have issues with throwing things away.
They delegate tasks but get angry when it is not done to perfection.
All have very bad issues with money, the opposite to the diagnosis, they can't make money last.
They are stubborn in that that they want reality to change for them.

Still I think DSM misses something that I feel is the core of this. These people suffer a lot, people around them suffer a lot.

ICD has this:

feelings of excessive doubt and caution;
preoccupation with details, rules, lists, order, organization, or schedule;
perfectionism that interferes with task completion;
excessive conscientiousness, scrupulousness, and undue preoccupation with productivity to the exclusion of pleasure and interpersonal relationships;
excessive pedantry and adherence to social conventions;
rigidity and stubbornness;
unreasonable insistence by the individual that others submit exactly to his or her way of doing things or unreasonable reluctance to allow others to do things;
intrusion of insistent and unwelcome thoughts or impulses.

They doubt a lot and rerun decisions in their heads a million times and drive people crazy asking them if it is right.
Yet again, no lists.
Same as above about task completion.
All do not put productivity before relations, but all put perfection before relations, EVEN when it is the relation they want perfect.
Stubborn yes.
No one understands that things CAN be do a different way than theirs.
No unwelcome thoughts, they all invite rumination.

If someone is actually really suffering from perfectionism, but does not live up to OCPD, what do they HAVE?