The Italian said last week that he had contemplated resigning as the Azzurri tactician in the summer after Napoli's defeat to Juventus in the Italian Super Cup in Beijing.
"The thing about possibly taking a sabbatical was not a joke," Mazzarri told Mediaset Premium. "I haven't had a break in 12 years.
"There's a lot of stress and out of a sense of fairness last year, when I was offered an extended contract, I refused. I will confirm what I said, which is I want to reach the end of the season and then reflect on whether or not to go forward.
"It is also a matter of my personal health and well-being. It could well happen, but I'll think about that later on, as right now I am concentrated on the next match against Chievo."
Mazzarri was appointed the Napoli coach in October 2009.