It's actually not only children that these particular drugs can permanently alter- and there have been (and I believe, still are) class action lawsuits going on for the off-label prescription of gabapentin, and more recently, Lyrica.
What many people don't understand about Gabapentin is that it is a synthetic form of an amino acid found naturally in our bodies (Gamma Amino-Butyric Acid), and only when someone has a deficiency of this amino acid is it beneficial to ingest as a supplement. The synthetic form, as with anything synthetic, fails to provide the same benefits without the added side effects.
While Neurontin and Lyrica may provide some degree of relief for people who may need GABA, most people are not aware of all of the effects on both hormones and mental status, especially if you do not need the extra GABA.

Of course, these are all things that I've been told by some health food and alternative therapy junkies- I don't know much about the way the whole thing works myself, BUT -From my personal experience, these are dangerous options, of which the 'cons' far outweigh the 'pros'.