Medication and drugs - the difference

Dopaminergic drugs (THC, cocaine, amphetamine drugs, alcohol, nicotine) work by rapidly increasing, very high and very rapidly decreasing dopamine levels in the striatum.¹ The rapid increase in dopamine triggers the intoxicating effect. With prolonged drug use (even with regular tobacco smoking or alcohol consumption), the prolonged excessive dopamine level leads to downregulation of the dopamine receptors and upregulation of the dopamine transporters. When the dopamine-boosting drug is discontinued, the normalized dopamine level is not sufficient to maintain the dopamine-regulated brain functions due to the low number of receptors and high number of transporters. The result is withdrawal symptoms that end within a few days or weeks after the dopamine receptors and transporters have regenerated.

Dopaminergic ADHD medications, on the other hand, do not act as intoxicants because they cause dopamine levels to rise very slowly, remain constant for a long time and fall slowly. Medication merely compensates for the existing dopamine deficit, it does not lead to a dopamine surplus. Since there is no excess dopamine, neither a state of intoxication nor a dysregulation of the dopamine receptors or transporters can occur.

Oral intake of methylphenidate causes a slow increase in dopamine levels, which does not lead to intoxication. In contrast, intravenous administration of MPH causes a more rapid increase in dopamine levels, which is associated with intoxication.²

While drugs can cause a state of intoxication due to the rapid rise in dopamine levels and the subsequent rapid drop, this possibility is not present when taking stimulants (methylphenidate and amphetamine drugs) orally (slow-acting).