Others are more universal — alcoholism and child sexual abuse — but made worse by a conservative culture unwilling to deal with them.
The program is broadcast on several networks estimated to reach about 400 million people in India. Since its debut, more than 13 million people have posted suggestions and messages of support on the show's website. The alcohol abuse episode sent 60,000 phone calls flooding the Alcoholics Anonymous helpline, said the show's co-director Svati Chakravarty.
"It was unprecedented in the history of AA worldwide."
Rights workers say Khan has used his celebrity with remarkable effect.
Stalin K, a rights activist and documentary filmmaker who appeared in the caste episode, said none of the issues raised were new, but that Khan's show was giving them far more attention than the glancing treatment they usually get in India's media.
"It's a different level of engagement," he said. "The conversations are much deeper."
Khan's reputation as a thinking person's superstar adds to the show's credibility, but for the most part he keeps to the background — only speaking when someone looks lost for words or to explain something to his audience.
In a recent episode, Khan interviewed a university professor who had battled years of discrimination for being a dalit — the lowest Hindu caste. Kaushal Panwar spoke about being taunted in her village school, about not being allowed to drink water from the same clay pot as upper caste children.
Khan interjected only a few times, mostly to give Panwar time to hold back her tears, and once to admonish his audience and viewers that "if I believe an accident of birth makes me superior to you, that is a mental illness."
It remains to be seen whether the show's momentum can translate into substantial reforms. But Stalin says Khan's work is vitally important.
"This amount of discussion in such a short amount of time is unprecedented," he said.
Associated Press writer Biswajeet Banerjee in Lucknow, India, contributed to this report.