We are most concerned with the capitate-stalked trichomes, as these contain the overwhelming majority of the psychoactive cannabinoids (THC, THCV, CBN). Different cannabinoids affect the high in a multifaceted manner.
THC:
delta-9-tetrahydrocannabinol & delta-8-tetrahydrocannabinol - THC mimics the action of anandamide, a neurotransmitter produced naturally in the body, which binds with the cannabinoid receptors in the brain to produce the ‘high’ associated with marijuana. THC possesses high UV-B (280-315 nm) absorption properties.
THCV:
tetrahydrocannabivarin - prevalent in certain South African and Southeast Asian strains of cannabis. It is said to produce a ‘clearer high’ & seems to possess many of the therapeutic properties of THC.
CBD:
cannabidiol - previously believed to be psychoactive, or to contribute to the high by interacting with other cannabinoids, conversely the most recent research indicates that CBD has negligible effect on the high, it is however a strong anti-inflammatory, and may take the edge off some THC effects, such as anxiety. CBD as a non-psychoactive cannabinoid appears to be helpful for many medical conditions. CBD biosynthesizes into cannabinol (CBN) & tetrahydrocannabinol (THC).
CBN:
cannabinol - a degradation product of THC, produces a depressant effect, ‘fuzzy’ forehead.
CBC:
cannabichromene - non-psychoactive , a precursor to THC.
CBG:
cannabigerol - non-psychoactive, hemp strains often posses elevated levels of CBG while possessing only trace amounts of THC.
Heavy trichome production is not necessarily an indication of a potent plant. Some hemp strains have moderate layers of trichomes yet pack only a strong headache. In a drug strain, a thick layer of trichomes is a symbol that it may well posses an elevated potency level, but it is certainly not a guarantee.
What defines a cannabis drug strain is the plant's ability to produce THC & THCV.