Part one of the series will focus on medications for ADHD and the group of medications known as “stimulants”. These medications are considered first-line given their effectiveness, and I will discuss non-stimulant medication options for ADHD in the next installment. The umbrella term “stimulants” actually refers to two similar but distinct subgroups of medications – the methylphenidate class and the amphetamine class (more on this later).
In order to talk about how medication works, we must first discuss our current understanding of what is happening in the brain in the condition we are trying to treat. As with any mental health condition, ADHD involves a myriad of brain regions and neurotransmitter systems. However, current research has focused on and identified the prefrontal cortex (or PFC for short) as the primary area of interest which is the brain area responsible for regulating attention, behavior, and emotion. Dysfunction in this area is theorized to lead to the impairments in inattention, distractibility, hyperactivity, impulsivity, and emotional dysregulation we see in ADHD.
More specifically, the theory is that ADHD symptoms result from an imbalance of two neurotransmitters, dopamine and norepinephrine (referred to as “monoamines”, “catecholamines”, and abbreviated to DA and NE, respectively). Take note that it is not simply a matter of having “too much” or “too little” of these neurotransmitters, but of having the right balance of both. Therefore, a medication that effectively modulates the levels of these two neurotransmitters in the PFC would help to treat ADHD. This, in a nutshell, is what stimulants do.
The two classes of stimulant medications (methylphenidates and amphetamines) alter dopamine and norepinephrine in the prefrontal cortex in similar, but not identical ways. Both block the reuptake, or “recycling” of dopamine and norepinephrine (and to a lesser extent, serotonin, the third monoamine), however amphetamines also cause the release of stored-up dopamine. Taken as a whole, these actions at the neuronal level are how stimulants exert their effects and help treat ADHD.
In addition to their desired/targeted effects, stimulants (as with all medications) can also cause side effects through the alteration of norepinephrine in the prefrontal cortex. These include increases in heart rate and blood pressure, alterations in metabolic rate, as well as insomnia, reduced appetite, and an increased feeling of nervousness or anxiety. It is worth noting that these effects are generally manageable and tend to diminish over time.
As always, please speak to your psychiatrist when considering any medication to assess if and how they could be part of your (or your loved one’s) mental health treatment. In the next installment of Psychopharm Made (More) Simple, we will be discussing the non-stimulant medications used for ADHD.
