article_snippet: Marijuana is much stronger than it was three decades ago, experts have warned.
article_snippet: Scientists found cannabis smoked today has tripled in strength since the 1980s.
article_snippet: Super strong: Marijuana sold on the market today has tripled in strength since the 1980s, scientists  warn .
article_snippet: , Andy LaFrate found that marijuana has tripled in strength in the last 30 years.
article_snippet: Andy LaFrate said: 'We've seen a big increase in marijuana potency compared to where it was 20 or 30 years ago. '
article_snippet: I would say the average potency of marijuana has probably increased by a factor of three.'
article_snippet: The THC content of cannabis has tripled in some strains because producers have been cross-breeding producers over the years as users demand stronger drugs, Andy LaFrate said.
highlights_snippet: Cannabis has tripled in strength in the last three decades, scientists warn .
  