Sadie's continued use of marijuana will lead to her brain's reduction of the neurotransmitter , which will require her to need more of the marijuana to achieve its effects.

Sadie's continue use of marijuana will lead to her brain's reduction of the neurotransmitter anandamide which will require her to need more of the marijuana to achieve its effects.

Explanation:

The active ingredient of marijuana is tetrahydrocannabinol (THC)which is responsible for causing change in the brain.

This activates specific receptors called cannabinoid receptor.This receptors are found in limbic and cerebral cortex region and cerebellum.

As these receptors are located in the brain, the effect of these receptors are also wide spread.In healthy brain, these receptors are activated by a neurotransmitter called as anandamide that have pain relieving effect and also play important function in brain.When THC activates these receptors,causes interference of the normal function.

marijuana also boost another type of neurotransmitter called dopamine after taking the drug.