Respiratory health and quality of life in chronic cannabis users: An exploratory study

Cannabis is the most used recreational drug, typically consumed by smoking. Its incomplete combustion produces pollutants similar to tobacco smoke, including carbon monoxide, particulate matter, and polycyclic aromatic hydrocarbons. However, the respiratory effects of cannabis smoke remain incompletely understood. This study aimed to explore and evaluate the impact of chronic cannabis smoking on respiratory health, particularly in individuals without tobacco used.

Individuals who had smoked cannabis for at least the past five years or on 100 or more occasions during the previous year were invited for an evaluation of respiratory health utilizing current standard methods: a questionnaire for symptoms (cough, phlegm, wheezing and dyspnea), pre and post-bronchodilator spirometry, IOS, DLCO_sb, and a HRCT.

Fifty-eight subjects were analyzed, including 20 exclusive cannabis smokers, 29 dual users, and 9 polysubstance users. Overall, 29% reported at least two chronic respiratory symptoms; 43% reported regular or poor general health; 66% had an abnormality in at least one lung-function test, with 57% showing an obstructive pattern; and 47% had at least one abnormality in the HRCT. No statistically significant differences were detected between groups; however, the study may have been underpowered to identify small between-group differences.

In this exploratory study chronic cannabis users, either exclusive or in combination with other substances, a high frequency symptoms, functional abnormalities, and tomographic findings have been documented, despite their young age.