(Though the guy was drinking the stuff as a supplement, which probably affected his personality a bit)
Are they the same lithium salts that are prescribed as medication for certain psychological disorders?
Dunno if modern medications may also include other active-ingredients to compliment lithium, but lithium itself is pretty much the same thing as sodium or potassium in terms of its simplicity as a chemical species.
Since lithium has a +1 charge as a cation (positively charged ion) in salt, it needs to be balanced with an anion (negatively charged ion), so the exact salt can vary in solid-form. But once it dissolves in water, such as in the body, then it's not really bound to the anion anymore and so the exact anion it was originally ingested with isn't particularly important.
Apparently some people used to drink [mineral water with lithium](https://en.wikipedia.org/wiki/Lithia_water).
Reference: https://en.wikipedia.org/wiki/Lithium_(medication)