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WARNING: Medication for ADHD should only be prescribed after careful diagnosis by a specialist. This information cannot replace sound medical advice and is only intended to support discussions with doctors and therapists.
Methylphenidate is one of the most important drugs for the treatment of ADHD and is also used to treat narcolepsy and depression. Methylphenidate is a stimulant.
A fundamental distinction must be made between stimulants as medicines and stimulants as drugs. A fast, high dosage (= drugs) that occupies the majority of the receptors and quickly decreases again leads to an excess of neurotransmitters and thus triggers a state of intoxication. In contrast, a slow, low dosage that only partially occupies the receptors (= medication) merely compensates for the neurotransmitter deficit that exists in ADHD and eliminates the symptoms triggered by this.
Stimulants act primarily as dopaminergic and to a lesser extent noradrenergic reuptake inhibitors.
Nicotine has an indirect stimulating effect by binding to acetylcholine receptors and indirectly causing the release of (among other things) dopamine.1
Stimulants have a dopaminergic effect on the nucleus accumbens and improve the symptoms of hyperactivity and self-activation/reinforcement processes, while the problems of response delay and working memory are mediated by noradrenergic effects of the locus coeruleus on the PFC. The effects of stimulants on attention and behavioral control are mediated by dopaminergic and noradrenergic effects.2
Details about stimulants
Stimulants (e.g. nicotine, methylphenidate, amphetamines, entactogens, cocaine) enhance dopaminergic neurotransmission in the striatum by increasing dopamine release and/or inhibiting presynaptic dopamine reuptake. Opioid substances (e.g. alcohol, cannabis, opioids) have an indirect dopaminergic effect via a μ-opioid receptor mechanism by activating dopaminergic neurons of the VTA and by directly addressing the opioid receptors.3
These mechanisms are utilized by every healthy brain through endogenous dopamine, endogenous endorphins and endogenous opioids. Intoxication is caused by a very rapid (phasic) increase in dopamine in the brain, which can only be caused by an increased release of dopamine from the vesicles. ADHD medications, on the other hand, as reuptake inhibitors, do not cause an intoxicating effect via a slow (tonic) increase, but increase the tonic / extracellular dopamine level.
Stimulants improve cognitive abilities. In a very extensive study of n = 766,244 test subjects, a relevant improvement in the examination results of ADHD sufferers taking stimulant medication was found, even if the performance level of non-affected persons was not reached. In contrast, selective serotonin reuptake inhibitors had no influence on examination results.4
In Europe, methylphenidate is the drug of first choice for children and the second choice (after amphetamines) for adults with ADHD. It has been known since 1944.
In the USA, 52.9% of adolescents with ADHD receive MPH and 39.3% amphetamine medication as their first prescribed ADHD medication. Over the course of treatment, MPH is the primary prescribed medication for around 40% and AMP is the primary prescribed medication for 33%.5
