I have been smoking weed fairly regularly over the past year and have also recently been diagnosed with ADD and currently take 36mg Concerta XL (methylphenidate hydrochloride) daily. I ve been told that smoking while on concerta can be very bad for me. As far as my research has taken me, many people say that from experience the two do not interact in any significant way, and as far as I know I can say the same. However, the doctor that prescribed the medicine said that the combination can make me depressed and demotivated, and give me more intense mood swings. Also, apparently concerta increases your heart rate, which I haven t really noticed until recently where I ve taken a break from smoking weed (only a week and a half so far). I skateboard every day and I ve always had an issue with sweating a lot very easily to the point where I ll look like I just came out the shower after 20 minutes of solid skating, but now my heart rate shoots up massively as well, which didn t seem to happen when I was smoking and taking the medication (even though I usually skate sober). So I m wondering if there s any information I m missing out on or if continuing to smoke weed while on concerta will be very detrimental to my health... I m aware this is a long question but I d very much like to know as much as I can because I enjoy weed immensely, but I also think the concerta benefits me a lot in many ways. Thanks for your time, a comprehensive answer would be hugely appreciated. :)