Except as otherwise provided in Section 41-29-142, any person convicted of a second or subsequent offense under this article may be imprisoned for a term up to twice the term otherwise authorized, fined an amount up to twice that otherwise authorized, or both.
For purposes of this section, an offense is considered a second or subsequent offense, if, prior to his conviction of the offense, the offender has at any time been convicted under this article or under any statute of the United States or of any state relating to narcotic drugs, marihuana, depressant, stimulant or hallucinogenic drugs.
Miss. Code § 41-29-147