A study that examines traits that predict psychological distress...
Excessive concerns about making mistakes, pernicious self-doubt, harsh self-criticism, impossibly high standards or expectations for performance, a strong and chronic tendency to evaluate one’s performance as not measuring up to levels expected by oneself or others - these are features of maladaptive perfectionism that predict psychological distress.
Read more, very interesting...:
http://www.psychologytoday.com/blog/dont-delay/201210/perfectionism-procrastination-and-distress
This article shows that perfectionism can be just as big a cause of stress as procrastination. That the correlation between the two is modest. Procrastinators seem only minimally self-critical. They have previous research as well as credible sources that they used in their research as well.