If you can't access that link then google the words: "body ecology serotonin" to find the link. :)
A wound which has become, or is becoming, infected may be more painful, look red around the skin edges, may feel hot and swollen, ooze pus. I'd recommend using an antiseptic cream on your cuts.
A deficiency of the neurotransmitter serotonin is believed to cause depression which can lead to self harm or suicide.
11 Powerful Tips to Boost Your Serotonin: Part II of "How Happiness Heals Your Brain":
https://bodyecology.com/articles/boost_serotonin_happiness_heals_brain.php