There is some evidence that cannabis use is associated with lower cognitive performance and symptoms of attention-deficit/hyperactivity disorder (ADHD), but the existing literature is relatively inconsistent, potentially due to small samples in previous studies. Using a dimensional design, the current study examined cannabis use severity and age of first cannabis use in relation to neurocognitive performance and ADHD symptoms in a large sample of community adults (N = 1,008, Mage = 38.49, 56.0% female). Participants were assessed for cannabis involvement, neurocognitive performance, and ADHD symptoms. Dimensional relationships were investigated using multiple hierarchical regressions. Using a covariate model of age, income, sex, alcohol use, and tobacco use, severity of cannabis involvement was significantly associated with greater endorsement of both hyperactive-impulsive and inattentive ADHD symptoms but not with any other cognitive measures in the full sample. Exploratory analyses found greater cannabis use severity was associated with digit span forward and hyperactive ADHD symptoms in young adults (n = 371) and was associated with greater delay discounting, hyperactive, and impulsive ADHD symptoms in high-risk cannabis users (n = 161). Age of first cannabis use was not significantly associated with any neurocognitive variables or ADHD symptomatology in all analyses. The current findings provide evidence of a link between current cannabis misuse and both hyperactive and inattentive ADHD symptoms in general, and possible links to attention and impulsive delay discounting in subgroups of cannabis users, but no associations in other cognitive domains or implication of earlier initiation of cannabis use in relation to cognitive performance or ADHD. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Early research suggests that cannabidiol (CBD) may help patients with epilepsy. It is also believed to relieve pain, anxiety, mood disorders, and even acne. But what about ADHD or ADD? So far, research linking CBD oil to ADHD symptom relief does not exist. That isn’t stopping patients from trying it.
“During [a person’s] development, I worry about cannabinoids, both CBD and THC,” says UCLA’s Evans. “There are adenosine receptors (and CB2 receptors) on the microglia that are critical for brain development, and CBD inhibits adenosine uptake. This may be a beneficial factor for epilepsy and autoimmune and inflammatory diseases, but who knows for ADHD.”
What Is CBD? Does It Help ADHD?
Dangers may also exist in the method of delivery. CBD is packaged and consumed in oils, tinctures, or edibles — each one absorbed differently by a person’s body. “The labeling in this industry,” says Vigil of UNM, “is horrific.”
The studies done on CBD and ADHD to date amount to… practically nothing. One 2011 study showed that, among a group of 24 people with social anxiety disorder, the half who’d taken CBD were able to speak in front of a large audience. In 2015, researchers in Germany examined the relationship between cannabis (CBD and THC) and ADD in 30 patients, all of whom said they experienced better sleep, better concentration, and reduced impulsivity while using the cannabis products. Finally, a 2017 study looking at CBD oil and ADHD in adults found that the oil improved some symptoms, but that more studies were needed to confirm its findings.
Also potentially harmful is the non-standard and wildly fluctuating amount of CBD in most CBD products, even those labeled as “pure CBD oil.” Some such products may also contain other ingredients — pesticides, additives, herbs, and even THC. “CBD alone has multiple actions on the cells in the brain and we don’t know which ones are clearly responsible for its known benefits,” Carson says. “It gets more complicated when we have less purified products that also include THC and CBDV [cannabidivarin].”
Washington: Regular users of cannabis are not good at creative thinking and are often less aware of their own mistakes, claims research on the effects of cannabis.
"It is important that we gather more knowledge about the effects of cannabis on a person's ability to detect mistakes. This can help with putting together a treatment programme for drug addiction," said Kowal.
The conclusion from other scientific research is that regular cannabis use does not necessarily have disastrous effects for the take-up of dopamine. It may well be that the age at which cannabis is first used is a crucial factor, Kowal suggested.
He also demonstrated that for chronic users the brain processes involved in monitoring mistakes also work less effectively. A high dose of cannabis seemed to influence both the unconscious processing of mistakes and also the later and more conscious stages of error processing.
The research also indicated clear long-term effects: cannabis disrupts the activity of dopamine in the brain. With chronic users, a significant reduction was seen in the frequency of spontaneous eye blinking, an indication of a reduction in dopamine production.