A study published in Addictive Behaviors found that regular users of cannabis showed diminished affective responses to stress as measured by their positive affect, stress, and anxiety following several stress tasks. Their cardiovascular responses to stress, however, were comparable to those of non-users.
While previous research has explored the effects of cannabis on emotional and physiological responses to stress, little research has considered these effects when it comes to prolonged cannabis use.
“This study examined potential differences in acute stress responses between regular cannabis users and non-users using an array of subjective (state stress, positive affect, state anxiety, cannabis craving) and cardiovascular (blood pressure, heart rate, mean arterial pressure) responses to stress,” study authors Briana N. DeAngelisa and Mustafa al’Absia say.
A total of 45 cannabis users and 34 non-users between the ages of 19-66 took part in a laboratory study. The study involved three stressors — a public speaking task, a mental arithmetic task, and a cold pressor task. Participants wore blood pressure cuffs throughout the study to record their blood pressure, heart rate, and mean arterial pressure. They also rated their feelings of cheerfulness, happiness, stress, overwhelm, and anxiety/tension at various time points throughout the study: at the start of the visit, after a 45-minute rest period, immediately following the stress tasks, and after a 30-minute recovery.
Results revealed an effect for cannabis use on subjects’ affective stress responses. When it came to stress and anxiety, non-users’ subjective ratings were at their highest directly after the stress tasks. Cannabis users, on the other hand, showed similar stress and anxiety levels following the stress tasks as they did at the start of the visit. Moreover, cannabis users showed smaller changes in both stress and anxiety than did non-users.
When it came to cheerfulness and happiness, non-users’ positive affect was at its lowest directly after the stressor task, when it was significantly different from all other time points. For cannabis users, positive affect did not fluctuate significantly throughout the experiment except when it peaked at the start of the study.
As researchers expected, the stress tasks were found to increase subjects’ systolic blood pressure, diastolic blood pressure, heart rate, and mean arterial pressure. However, the study found no differences in the cardiovascular stress responses of cannabis users and non-users.
The authors assert that this does not mean that the prolonged use of cannabis has no effect on a person’s cardiovascular response to stress. Instead, it could be that cardiovascular differences were simply not captured by this study. “For instance,” they say, “future studies might examine potential differences between cannabis users and non-users in heart rate variability (HRV) as well as changes in hemodynamic measures in response to acute stress. It is well-established that acute stress tends to influence HRV; and previous research has found that cannabis users tend to have elevated basal HRV.”
The authors conclude that habitual cannabis use is linked to weakened affective response to acute stress and that future research “is needed to better understand the implications of these findings in initiation and maintenance of cannabis use.”
The study, “Regular Cannabis Use is Associated with Blunted Affective, but not Cardiovascular, Stress Responses”, was authored by Briana N. DeAngelis and Mustafa al’Absi.
