"discussions touched on" is correct and usable in written English.
You would use this phrase when you want to say that two or more people discussed a certain topic. For example, "The discussions touched on the importance of taking regular breaks throughout the day."
Their discussions touched on questions of morality and mortality; trust in doctors and God's grace; and the right of the dying to determine their own fate versus protection for the elderly and vulnerable.
Apart from realism and antirealism, our discussions touched on many topics, including the importance of fighting racism, an area in which Michael was exemplary, not just as a thinker, but as a human being.
The focus was prediction and prevention in India, and discussions touched on the tremendous opportunities and significant challenges associated with designing, initiating, and conducting research, as well as pursuing related public health programming to improve public health infrastructure in the face of climate change.
He said to me that he would not grow old, both in discussions of his paper on senescence ("I feel bucked when anyone refers to that paper") and discussions touching on personal safety.
Great question and answer sessions followed discussions touching on the reality for women not only in the West, but also in the developing world.
Try to avoid charging into political discussions touching on religious ideas: abortion, gay marriage, and the like.
The subject arose when Groundswell held a retreat last fall and the discussion touched on a project focused on dating violence and young women.
Our discussion touched on eighties commercials, various synthesizers, the myths surrounding nostalgia, bad New Age records, animals as machines, and a clutch of other topics.
None of the Presidential debates and little of the public discussion touched on the dramatic historical shift that had been taking place in the world since 1989.
Their teacher, Jason Bavuso, let them choose any book that engaged them, so the discussion touched on "Runaway Jury" by John Grisham; "A Million Little Pieces" by James Frey; and a Civil War memoir, "Company Aitch".
One discussion touched on patterns of collaboration in research, and that got me wondering if anyone had analyzed trends in co-authorship of science papers as a possible indicator of the global "match.com" potential of various Web tools for fostering collaboration among experts with variegated skill sets.
