ADHD and the endocannabinoid system

Column by Wilson Lessa*

ADHD (Attention Deficit Hyperactivity Disorder) is considered a neurodevelopmental disorder that is very common and appears to be increasing in diagnosis, partly due to better clinical investigation and environmental factors.

This disorder affects a person's ability to regulate their attention, emotions, impulsivity, and hyperactivity. It can be diagnosed in both childhood and adulthood (although in this case, the symptoms were already present early in life).

This disorder affects a person's ability to regulate their attention, emotions, impulsivity, and hyperactivity. It can be diagnosed in both childhood and adulthood (although in this case, the symptoms were already present early in life).

Comorbidity (the co-occurrence of pathologies) with other conditions such as anxiety disorders, depression, and substance abuse is common.

ADHD is didactically subdivided into three types: 

1. Predominantly inattentive;
2. Predominantly hyperactive-impulsive;
3. Combined inattentive-hyperactive-impulsive;

The neurotransmitters dopamine, norepinephrine, and serotonin are believed to be dysregulated in this disorder. Multiple genetic variations involving these neurotransmitters have been found in patients with ADHD.

Dopamine sends messages between parts of the brain that control reward and motivation (nucleus accumbens); planning, problem-solving, and attention (prefrontal cortex); and cognition and learning (dorsal striatum). People with the hyperactive-impulsive subtype appear to have an exacerbated metabolism of dopamine, which negatively interferes with its effects.

Norepinephrine is involved in vigilance (alertness), attention, and memory, and its deficiency is related to attention deficits. Loss of impulse control and aggression are more a consequence of serotonin dysregulation.

Stimulants are the most prescribed medications for controlling ADHD symptoms, as they increase dopamine and norepinephrine neurotransmission. Although effective for many people, they often have side effects such as loss of appetite, insomnia, increased blood pressure, weight loss, tics, headaches, and stomach pains.

There is already evidence that patients with ADHD have genetic dysfunctions related to the endocannabinoid system and excess metabolism of anandamide, our main endocannabinoid

There is already evidence that patients with ADHD have genetic dysfunctions related to the endocannabinoid system and excess metabolism of anandamide, our main endocannabinoid (Centonze et al., 2009). 

It is important to remember that the Endocannabinoid System is involved in modulating neurotransmission and that abnormalities in its function can contribute to ADHD symptoms.

There are already some reports in the scientific literature of the benefits of therapeutic use of Cannabis derivatives in these cases:

- A 28-year-old patient with ADHD was able to function normally with high doses of THC, including passing a driving test. The researchers in this case wrote,