John Oliver tackled America’s mental health problem on Sunday, using Republican presidential candidates as symbols of the lack of seriousness on the issue.

“Perhaps the clearest sign of just how little we want to talk about mental health is that one of the only times it’s actively brought up is, as we’ve seen yet again this week, is in the aftermath of a mass shooting as a means of steering the conversation away from gun control,” the HBO satirist said.

Oliver then played a series of clips of Donald Trump, Ben Carson and Mike Huckabee responding to mass shooting by calling for an enhanced focus on mental health.

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“It seems there is nothing like a mass shooting to suddenly spark political interest in mental health,” he continued. “Although it’s worth noting that Governor Huckabee’s state [Arkansas] got a grade of D- on mental health care while he was in office. And you can’t lecture people on something you got a D- in.”

Also Read: Stephen Colbert on Oregon School Shooting: 'I Honestly Don't Know What to Do or Say' (Video)

“If we’re going to constantly use mentally ill people to dodge conversations about gun control, then the very least we owe them is a f–king plan,” Oliver concluded.

Watch the video above.

8 Attacks on Free Speech Before Shooting at French Paper Charlie Hebdo (Photos)

The deadly terror attack on French satirical newspaper Charlie Hebdo is shocking but, sadly, not unprecedented.
1998: Novelist Salman Rushdie received death threats after the publication of his book "The Satanic Verses," which was seen by some Muslims as insulting to Muhammad.
2002: Whether because he was a journalist or American, Wall Street Journal's Daniel Pearl was beheaded by al-Qaida. The Committee to Protect Journalists reports 731 members of the media have been murdered since 1992.
2004: Dutch filmmaker Theo van Gogh angered Muslims with his film "Submission," which was critical of the way women are treated in Islam. He was murdered by Dutch-Moroccan Muslim Mohammed Bouyen.
2005: The Danish newspaper Jyllands-Posten published a number of controversial cartoons depicting the Islamic prophet Muhammad, leading to protests and violent demonstrations in some Muslim countries.
2011: CBS journalist Lara Logan was beaten and sexually assaulted while covering the celebrations in Egypt's Tahrir Square over the resignation of Egyptian president Hosni Mubarak.
2014: After being threatened by Israelis in Sderot, CNN's Diana Magnay caused an uproar by calling them "scum" on Twitter. Magnay was then pulled off of her assignment near the Gaza border and reassigned to Moscow.
2013: Al Jazeera journalists Peter Greste, Mohamed Fahmy and Baher Mohamed were arrested and later convicted in Egypt of aiding and abetting the Muslim Brotherhood, receiving prison sentences ranging from seven to 10 years. While an Egyptian court has accepted the trio's appeal, the journalists were not released on bail, meaning they'll remain imprisoned until their retrial.
2014: The theatrical release of the comedy "The Interview," which depicted an assassination plot against North Korean leader Kim Jong-un, was temporarily canceled after Sony suffered a massive cyberattack, in which North Korea reportedly played a part.