Given Lavrov has developed a pattern of describing some twisted alternative reality with a straight face, why should we believe anything he says? The point of diplomacy is to create mutual understanding, and his goal appears to be the exact opposite. His words are now somewhere between meaningless and harmful, and he should be completely ignored until he resumes communicating in good faith.

Being a Russian citizen, I think absolutely nothing coming from the Kremlin should ever be trusted. If they actually say something true, that's more likely to be an unhappy coincidence.

I don't like Lavrov, but this time I have to say that I agree with him.

Using nuclear weapons will likely trigger an equal response from the other side (NATO) and no one wants this. I could imagine nukes being used when enemy troops are approaching Moscow, as a desperate attempt to change the outcome of the war, or as a sort of mutual suicide like "if we die, you will die with us". However, Russia itself is not at risk now as this war is taking place in Ukraine.

Even in the case that Putin has lost his mind and gone mad, and he decides to launch ICBM with nuclear weapons just because he's having problems in Ukraine, he wouldn't be able to do it alone. I read just today that there are three chegets (Russian nuclear briefcases) and at least two of them are needed to command a nuclear attack. Putin has one of them, the others being in the hands of Shoigu and Gerasimov, and I don't think they are ready to die for a mad man.

The problem is that you're only thinking of Russia's startegic arsenal. One avenue of escalation Russia could realistically do is the use of tactical nukes in regular battle with Ukraine's army; not only is their "security" weaker but it also becomes a lot harder for NATO to justify retaliation if the the first nuke of the war is against a FoB in the middle of a wheat field.

What if they are all mad?

I am pretty sure the Russian elite is selecting for psychopaths and sociopaths. Lavrov and Putin being the most dangerous of the bunch.

As a species, we need to find a strategy to remove individuals with strong traits from the dark triad from power, before they can cause harm. They should neither lead a team, nor a country.

Putin might actually believe this alternate reality he is living in. The people around him too..