Δ9-THC has been shown to alter BDNF expression in animals [29, 49, 138, 191, 223]. Acute injection of Δ9-THC has been shown to induce BDNF mRNA transcription by stimulating CB1R and activating the ERK signaling pathway [49, 191, 223]. D’Souza et al. [47] showed that a socially relevant dose Δ9-THC increased serum BDNF levels in healthy control subjects. Furthermore, light users of cannabis had lower basal BDNF levels. The lower basal BDNF levels in light users of cannabis suggest that chronic exposure to cannabinoids can lead to a suppression of BDNF release. How this impacts the developing brain is not known. While admittedly speculative, this may provide a mechanism underlying the observation that cannabis precipitates schizophrenia or alters the course of the disorder.
