I take Ritalin LA 50mg (30mg 20mg tablets). I feel occasionally that it's a bit too much and wonder should I take a holiday or maybe just take 30mg or 40mg (2x20mg) or just 20mg, or maybe none, or is it dangerous to randomly lessen the dosage? What I mean by it being a bit too much.. Well, some stressful or busy days when I take 50mg I feel a bit jittery and agitated. The other day I didn't take anything and it seemed much a calmer day, but I didn't do much. Was kinda just nice to have a break to my busy life. The next day (today) I took 30mg and maybe back to 50mg tomorrow. However initially when I was only 30mg I felt it didn't affect much anything so we increased the dose. I also still occasionally (1-2 times a week) have a bottle of wine after 8-10hours taking the meds, so they're out of the system.

Edit: the biggest benefit for me from Ritalin LA is that it actually lowers my BP and heart rate in the long run.