As seen in Psychology Today.

Attention-deficit/hyperactivity disorder (ADHD) has become one of the most commonly diagnosed psychiatric disorders in recent years, with an estimated global prevalence of 2.5% in adults and 5% in children. In the United States, prevalence among individuals between the ages of 4 and 17 years was estimated to be 10% as of 2016. The most recent data available on the website for the Centers for Disease Control and Prevention indicated that the prevalence of ADHD is particularly high among children between the ages of 12 and 17 years (13%), and that prevalence is lower among children within lower age ranges: 2% for 3-5 year-olds and 10% for 6-11 year-olds.

The symptoms for ADHD are not uniform across all patients, and there is a growing awareness that adults often have more subtle symptoms than children. In the past, ADHD was typically conceptualized as a disorder affecting adolescents and characterized by an inability to keep still or pay attention in class. In more recent years, this conceptualization has evolved to include individuals of all ages who have difficulties managing time, staying on task, and controlling impulses. Additionally, clinicians have become more astute at recognizing subtle symptoms, which may not be on display in the examining room or classroom but are discernible on the patient’s report cards or (for adults) due to their inability to manage time effectively, remain steadily employed, or maintain healthy relationships. ADHD also is associated with higher incidences of anxiety, depression, bipolar disorder, substance use disorder, and sleep problems like insomnia. These comorbidities can have a negative impact on quality of life.

While there are effective pharmaceutical treatments available that include stimulants and non-stimulants, stimulants are prescribed far more often and can lead to adverse events that include emotional dysregulation, irritability, decreased appetite, insomnia, tachycardia, arrhythmia, and hypertension. For patients who cannot tolerate these side effects, there is a need for novel treatment options. A new study by Ittiphakorn and colleagues published in Neuropsychopharmacology Reports suggests that cannabis may be one of those options.

Cannabis 101

Cannabis is a plant that contains hundreds of potentially therapeutic compounds. The two compounds that occur in the highest concentrations of virtually all cannabis are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC is the primary intoxicant found in cannabis, and it leads to the effects that most people associate with marijuana. THC content is also legally important, as cannabis that is more than 0.3% THC by weight is legally considered marijuana. CBD does not cause intoxication, but it can produce a feeling of relaxation.

Both THC and CBD interact with the endocannabinoid system (ECS), which is partially responsible for promoting homeostasis throughout the body. The ECS is also widely distributed throughout the central nervous system (CNS) and plays a role in regulating emotion, sleep, appetite, motor coordination, memory, reward pathways, and even executive function. Many of these areas of cognition (especially executive function, reward pathways, and emotion) are affected by ADHD. Consequently, there is at least a theoretical basis for testing the efficacy of cannabis in the treatment of the disorder, even if there is limited clinical evidence (see Cooper et al and Francisco et al) to support its use.

Cannabis and ADHD

Before delving into the findings of Ittiphakorn and colleagues, it’s important to note that this study did not involve any children. Moreover, cannabis that contains more than trace levels of THC should not be a first-line treatment for any psychiatric disorder if the patient is under the age of 18, as THC may damage developing brains. There are always other options for children.

The study involved 68 adults from the United Kingdom, 55 (81%) of whom were men and 55 (81%) of whom were current users of cannabis. Participants were asked to complete patient-reported outcome measures (PROMs) at baseline and after 1 month, 3, 6, and 12 months, as well as to report any adverse events. These PROMs focused on patient’s level of anxiety (generalized anxiety disorder-7 [GAD-7]), sleep (single-item sleep quality scale [SQS]), and quality of life (European quality of life five-dimension, five-level [EQ-5D-5L] and Patient Global Impression of Change [PGIC]). The number of patients who completed PROMs at 1, 3, 6, and 12 months after baseline were 61, 53, 50, and 33, respectively.

Route of administration of cannabis was varied, with 38 only using dried flower, 4 using only sublingual oils, and 26 using both. Median CBD dose was 15 [5.13-55.00] mg, while median THC dose was 208.75 [120.63-291.43] mg, which seems extremely high, given that a typical therapeutic dose of edible THC for cannabis naïve patients is 5-10 mg. However, a typical cigarette made of dried flower contains 0.3 g of plant material and up to 75 mg of THC (assuming a THC content of 25%), much of which is lost in the smoking process. Therefore, it seems doubtful that multiple patients were ingesting such a high dose of THC.

Across the board, the team observed improvements in anxiety levels, sleep quality, and quality of life (EQ-5D-5L) when compared to baseline at 1, 3, and 6 months. Improvements in anxiety and sleep were reported after 12 months, but similar improvements were not observed using EQ-5D-5L. For PGIC, the median score reported at baseline remained the same at 1, 3, 6, and 12 months. Eleven patients reported adverse events, none of which were severe. Patients were also able to reduce the use of lisdexamfetamine [Vyvanse], methylphenidate [Ritalin], and dexamfetamine [Zenzedi], by 38.46%, 15.00%, and 14.29%, respectively. There was no statistical difference with respect to route of administration of cannabis.

Though the study does have multiple limitations, particularly its lack of controls, women, and standardization among samples of cannabis, it does indicate that cannabis-based medicines can help improve quality of life for patients with ADHD. While it does not make the case that cannabis is useful in treating the core symptomology of ADHD, it may mitigate the adverse effects of stimulant medications (particularly sleep problems) and alleviate comorbid anxiety.

This blog was written entirely by a human with no assistance from generative AI tools.