Additional experiments revealed that mice given access to an exercise wheel or treated with antidepressants also exhibited increased CB1 receptor levels in astrocytes. Furthermore, analysis of human brain tissue from the Douglas-Bell Canada Brain Bank indicated that individuals with major depression had lower astrocytic CB1 receptor levels compared to those without depression or those who had received antidepressant treatment.

Implications for mental health interventions

These findings raise the possibility of developing treatments that selectively activate CB1 receptors in astrocytes to mitigate anxiety and depression. However, the challenge remains in limiting activation to astrocytes, as prolonged CB1 receptor stimulation in neurons can lead to side effects affecting alertness, anxiety and appetite. Until targeted pharmacological interventions become available, engaging in physical activity may help protect against stress-related mental health conditions by enhancing CB1 receptor expression.