"i have been on this medication for almost 11 years i believe that the capsule time released at least for me work a lot better because of the longevity as well as impact. the instant release a great but for me i have a past history with drug abuse in the instant release seems to give a high effect for about an hour and then you come down as well as you don&#039;t feel the effects of the medication working properly. again i can only speak for myself but the time released helps to keep me at an even keel and i stay level for the whole day through no highs and lows."