Lunch on drugs

28 January 2011

 A smouldering joint
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Joint, by Marcos Fernandez, on Flickr

Packed Lunch returns soon with more tales of research from local scientists. To get you in the mood, we’re catching up with some of last year’s, via the Packed Lunch podcast. In December, Benjamin Thompson went along to hear from a scientist who comes round to your place when you’re getting high…

This month’s Packed Lunch at the Wellcome Collection concentrated on the study of illegal drugs. The room was full to bursting, leaving many of the guests sitting on the floor. Whether they were there because the Collection’s excellent High Society exhibition had raised their intrigue in the illicit, or because they were active users of non-prescription medications, the talk raised a huge amount of questions and stimulated a high level of debate.

This month’s interviewee was Dr Celia Morgan, a research fellow in clinical psychopharmacology from UCL. Dr Morgan’s area of research focuses on both cannabis and ketamine.

With her recent cannabis studies, Morgan described an interesting approach to gathering data, very different to what I perceived most drug studies to be like. Rather than exclusively observing the effects of the narcotic in a lab based environment, she goes round to people’s houses to test them at home.

Volunteers are all students from UCL, who have been checked to ensure they have no family or personal history of psychosis, nor any serious head injuries in the past. Dr Morgan and colleagues visit the volunteers twice; on the first visit the team take a hair and urine sample, then ask the volunteer to skin up, get high, and undertake some cognitive tests. A sample of weed is also taken for analysis.

A week later the same volunteer is visited and the tests are repeated, except this time the subject is ‘straight’. Saliva samples are taken to ensure no drugs have been taken in the past few hours.

Why are the hair samples taken? It turns out that hair acts like the rings of a tree, keeping a record of all the drugs you’ve taken in the past. On average a person’s hair grows about 1 cm per month, so by taking a 3 cm length a record of all drugs ingested over the past 3 months is available. This can be more useful than asking the volunteers themselves to remember what they’ve taken, especially as the substances used can impair memory!

What about the weed samples? Why are they taken? Dr Morgan explained that these are tested to assess the levels of two active compounds: tetrahydrocannabinol, or THC, is the most well known and produces the ‘high’ associated with cannabis, but also assessed is the level of cannabidiol, or CBD, which appears to reduce anxiety at high doses and may act as an antipsychotic, counteracting the effects of THC.

Levels of CBD in cannabis are dropping, not due to consumer demand for more potent strains with higher levels of THC, but due to modern growing conditions – indoors, frequently under constant lighting in UK factories – which appear to be lowering the plants’ natural levels of CBD.

Too little CBD may lead to acute memory loss over time and an increase in levels of proneness to psychosis.

Dr Morgan’s other research is on ketamine, a substance developed as an anaesthetic in the 1960s. Ketamine is still used today, mainly due to its safety, as it doesn’t interfere with a patient’s breathing. However, the drug has several unpleasant/pleasant side effects, depending on how you look at it. Patients described vivid hallucinations after surgery, and because of this the drug became popular for recreational use.

Ketamine began being used in the UK during the rave scene in the 1990s, when it was frequently cut with ecstasy. At low doses the drug is a stimulant, whilst a mid-strength dose may cause the user to experience bodily distortions, with limbs feeling much longer or shorter than they really are. A high dose can result in the user becoming catatonic, known colloquially as a ‘k-hole’. There is no comedown associated with ketamine as there frequently is with other drugs.

So far this sounds interesting. Sadly, however, there are a number of dangerous downsides associated with the use of this drug. Ketamine is addictive, and Dr Morgan suggests that this may be due to its short action time. Heavy users may experience both mental and physical issues, including severe memory problems and the charmingly named ‘ketamine-associated ulcerative cystitis’. This irreversible condition is caused by the drug physically binding to the bladder, which can ultimately result in bladder removal.

Dr Morgan is interested in the drug as its use is becoming more popular in the UK, but little research has been undertaken on its mode of action and long term effects. She hopes the work on this drug, and that on cannabis, will help inform the public and hopefully drive future government drugs policy in an evidence based, rather than media frenzied, direction.

Benjamin Thompson is a writer at the Wellcome Trust.