Potency of Δ⁹–THC and Other Cannabinoids in Cannabis in England in 2005: Implications for Psychoactivity and Pharmacology*

Abstract

Gas chromatography was used to study the cannabinoid content ("potency") of illicit cannabis seized by police in England in 2004/5. Of the four hundred and fifty two samples, indoor-grown unpollinated female cannabis ("sinsemilla") was the most frequent form, followed by resin (hashish) and imported outdoor-grown herbal cannabis (marijuana). The content of the psychoactive cannabinoid delta 9-tetrahydrocannabinol (THC) varied widely. The median THC content of herbal cannabis and resin was 2.1% and 3.5%, respectively. The median 13.9% THC content of sinsemilla was significantly higher than that recorded in the UK in 1996/8. In sinsemilla and imported herbal cannabis, the content of the antipsychotic cannabinoid cannabidiol (CBD) was extremely low. In resin, however, the average CBD content exceeded that of THC, and the relative proportions of the two cannabinoids varied widely between samples. The increases in average THC content and relative popularity of sinsemilla cannabis, combined with the absence of the anti-psychotic cannabinoid CBD, suggest that the current trends in cannabis use pose an increasing risk to those users susceptible to the harmful psychological effects associated with high doses of THC.

Cannabis users have higher premorbid IQ than other patients with first onset psychosis

“…Statistically significant differences between cases and controls were, however, found in the type and the frequency of cannabis used. Cases were more likely than controls to have preferentially smoked "skunk" which has a relatively high concentration of ∆9-THC (12-18%) (Potter et al, 2008), and were more likely to have used cannabis everyday than controls. There were no significant differences between cases who used cannabis and those who did not in gender, age, ethnicity, years of education, mother tongue nor in any of the PANSS subscales: negative (t(111) = −1.187, p = .238), positive (t(111) = .677, p = .500) and general psychopathology (t(111) = −.386, p = .700) scores (data not shown in tables).…”

Differences in cannabis-related experiences between patients with a first episode of psychosis and controls

“…In our study those using imported herbal cannabis were included in the high-potency category due to the high level of THC contained (Potter et al 2009). …”

“…In recent years, alongside traditional marijuana (grass) and resin (hash), a new potent variant (often termed skunk) has become widely available in many countries. Potter et al (2009) reported skunk-type cannabis seized in 2005 in England to have an average Δ 9 -tetrahydrocannabinol (Δ 9 -THC) content of 12.9% compared with an average 3.6% of hash-type cannabis, while the UK Home Office (Mwenda et al 2005) reported a slight increase in the average content of Δ 9 -THC for both types: 16.2% in skunk and 5% in hash. Both potency studies also reported that cannabidiol levels were almost absent in high-potency skunk-like cannabis (0.1%).…”

Oral Cannabidiol does not Alter the Subjective, Reinforcing or Cardiovascular Effects of Smoked Cannabis

“…CBD has low affinity for CB 1 and CB 2 receptors (Pertwee et al, 2010), binds to TRPV 1,2 , GPR55, and 5HT 1a receptors and inhibits anandamide hydrolysis via FAAH inhibition (Mechoulam et al, 2002;Grotenhermen, 2005;Ryberg et al, 2007). Hashish may contain equal parts CBD and THC (ElSohly et al, 2003;Hardwick and King, 2008;Potter et al, 2008), but CBD is typically present in low concentrations in recreational cannabis (o0.1%), based on samples seized by law enforcement.…”