Common side effects of long-term SSRI use in adults include weight gain, emotional numbing, loss of libido, and sexual dysfunction. It seems to me that anyone taking SSRIs when their brain is still developing would be more likely to have these side effects, and to have them persist after ceasing use.
It's anecdotal, but I know some people who were prescribed SSRIs during puberty. It's not possible to know how they would have turned out if they hadn't taken these drugs, but as adults I pity them. Their lack of sex drive causes relationship problems, which is especially sad since they do want children. They're starting to get older, so I doubt it'll ever happen.
1. https://en.wikipedia.org/wiki/Selective_serotonin_reuptake_i...