Might a higher dose pose a health or welfare problem for the patient?
It seems generally true that in any individual patient a higher dose is more likely to induce side effects that a lower dose. However, there is great variability among patients in the dose required to cause side effects. This can be understood in terms of the ratio of the adrenalin-like effects of the stimulants on the mind and on the body. In the best of circumstances the effect on the body is minimal and that on the brain sufficient to be effective. But not infrequently patients have a reverse ratio and experience a preponderance of adrenalin-like side effects with minimal or no beneficial cognitive effects. I have seen many patients who develop side effects like increased heart rate or sleeplessness on what might seem to be a very low dose (e.g. 2.5 mg of amphetamine) while others seem impervious to side effects at high doses (e.g. 160 mg per day of amphetamine). This being true, all things being equal, it seems best to follow the standard procedure of starting treatment with a low