Morgan C J A, Gardener C, Schafer G, Swan S, Demarchi C, Freeman T P, Warrington P, Rupasinghe I, Ramoutar A, Tan N, Wingham G, Lewis S, Curran H V
Clinical Psychopharmacology Unit, UCL, Gower Street, London WC1E 6BT, UK.
Psychol Med. 2012 Feb;42(2):391-400. doi: 10.1017/S0033291711001322. Epub 2011 Jul 29.
Cannabis varies considerably in levels of its two major constituent cannabinoids - (delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Recently, we found evidence that those who smoked cannabis containing detectable levels of CBD had fewer psychotic-like symptoms than those whose cannabis had no CBD. The present study aimed, first, to replicate those findings and, second, to determine whether protective effects of CBD may extend to other harms of cannabis, such as memory impairment and reduced psychological well-being.
A total of 120 current cannabis smokers, 66 daily users and 54 recreational users were classified into groups according to whether analysis of their hair revealed the presence or absence of CBD and high versus low levels of THC. All were assessed on measures of psychosis-like symptoms, memory (prose recall; source memory) and depression/anxiety.
Lower psychosis-like symptoms were found in those whose hair had CBD compared with those without. However, this was seen only in recreational users, who had higher levels of THC in their hair. Higher THC levels in hair were associated with increased depression and anxiety. Prose recall and source memory were poorer in daily users with high THC levels in hair while recognition memory was better in individuals with CBD present in hair.
CBD attenuates the psychotic-like effects of cannabis over time in recreational users. Higher THC negatively impacts on memory and psychological well-being. These findings raise concerns for the harms stemming from use of varieties such as 'skunk' (sensimillia), which lack any CBD but currently dominate the supply of cannabis in many countries.
大麻的两种主要成分大麻素——（δ-9-四氢大麻酚（THC）和大麻二酚（CBD））的含量差异很大。最近，我们发现有证据表明，吸食含有可检测水平CBD的大麻者比吸食不含CBD大麻者出现的类精神病症状更少。本研究旨在，首先，重复这些发现，其次，确定CBD的保护作用是否可能扩展到大麻的其他危害，如记忆损害和心理健康下降。
共有120名当前吸食大麻者，66名每日使用者和54名偶尔使用者，根据他们头发分析显示是否存在CBD以及THC水平的高低进行分组。所有参与者均接受类精神病症状、记忆（散文回忆；来源记忆）和抑郁/焦虑的测量评估。
头发中含有CBD的参与者与不含CBD的参与者相比，类精神病症状更少。然而，这仅在头发中THC水平较高的偶尔使用者中观察到。头发中THC水平较高与抑郁和焦虑增加有关。头发中THC水平高的每日使用者的散文回忆和来源记忆较差，而头发中含有CBD的个体的识别记忆较好。
随着时间的推移，CBD可减轻偶尔使用者中大麻的类精神病作用。较高的THC对记忆和心理健康有负面影响。这些发现引发了对使用诸如“臭鼬”（优质大麻）等品种所产生危害的担忧，这些品种不含任何CBD，但目前在许多国家主导着大麻供应。
