It looks (to me) like the White House didn’t necessarily single out and block this particular petition, but created just one response to cover 33 different petitions regarding recent gun violence. See the copy of the response at: https://petitions.whitehouse.gov/response/message-president-obama-about-your-petition-reducing-gun-violence Near the top, it says: “OFFICIAL WHITE HOUSE RESPONSE TO Start the process to enact Federal Gun control reforms. and 32 other petitions A Message from President Obama about Your Petition on Reducing Gun Violence” If you follow the “32 other petitions” link, it looks like none of the other referenced petitions say anything about problems with psychiatric drugs. So it might(?) have been just a (stupid) oversight that they missed the point of this particular petition when they scooped it together with all the others. That’s not an excuse, but it’s not as bad as specifically shutting down this petition in particular.