I’m grumpy about the aside that some medical conditions cause procrastination yet refusal to list them. They don’t need to diagnose readers to just list common issues for which the DSM lists procrastination. That might encourage more sympathy when we see others procrastinating.
A quick search would suggest that ADHD would call this a sign and procrastination can be a side effect in major (clinical) depression, bipolar disorder, monotropism, Aspergers spectrum disorders, and non-categorized issues with shame and low self-esteem (at least that one is covered in the article).