Effects of THC and CBD on Human Episodic Memory Function
Status:
Completed
Trial end date:
2014-12-01
Target enrollment:
Participant gender:
Summary
THC and CBD have distinct symptomatic and behavioral effects. In healthy individuals, THC can
induce psychotic symptoms and anxiety, and can impair memory. In contrast, CBD has anxiolytic
and possibly antipsychotic properties, while not impairing memory and other cognitive
functions. Instead, CBD has been shown to have significant neuroprotective effects. In
humans, CBD values correlated positively with gray matter concentration in bilateral
hippocampus. Recent data from experimental animals and in vitro studies suggest that these
distinct effects might be caused by opposing effects on brain cannabinoid receptors.
Neuroimaging studies have consistently identified brain activity recorded at prefrontal and
medial temporal regions as relevant for episodic memory. Additionally, the abundance of
cannabinoid receptors in the hippocampus and the parahippocampal and entorhinal cortices
suggests a potential impact of CBD in memory deficits typical in healthy aging. However, the
evidence relating cannabinoids to these conditions is relatively recent and has been obtained
from either biochemical or pharmacological studies. It might be hypothesized that CBDs could
be useful to delay or even arrest the progression of functional and structural neuronal
degeneration.
The investigators will use an episodic memory paradigm to test the effects of THC, CBD and
placebo on memory encoding and retention and the underlying neuronal networks on healthy male
subjects.