Well the first one is more difficult and dangerous than the second. I wouldn't recommend trying to bring forward memories like that unless you are intending to drive them insane. Truth spells on the other hand are a dime a dozen. They're relatively harmless depending on the nature and size of the lie(s) and what sort of damage the truth could cause. Sometimes people spin so many lies, that the truth itself could destroy the entire illusion they have built around their lives. So if you care about this person, you may wish to consider that. It is hard to guide a general truth spell. It is usually safer to cast on yourself--that you may see through the lies.
What I believe you are looking for is more of a realization spell. You want them to gain a revelation that what they are doing is hurtful and that they should stop. Am I right?