Completed [GBR] Long-term effects of ketamine use

"About 8 people who use drugs (but not ketamine) about twice a month and have done for at least one year."

If i'm able to do it from here in Chicago (USA), I'm in. I've never used ketamine, I'm a heavy marijuana smoker, I used to abuse the hell out of ecstasy (now I do it once a week, I know it's still pretty bad), I'm also very experienced with LSD and mushrooms (and have done some different research chemicals), and have pretty much experienced it all except heroin, pcp, and smoking meth and crack.
 
^ probably not. a flight from london to chicago isn't cheap.

i would also participate but i'm in california :(

good luck with finding more subjects, i can't wait to see how this turns out.
 
I live in London and really near UCL so I can actually make it there if that's better.

PM me or something with times and stuff.

One of my friends will also want to do it.
 
If this is still happening me and one friend would be very interested in doing this.

I only live like 30 mins from UCL so travel will be fine. Can you get back to me Justin please.
 
id do it, but im in australia..... id be the absolute perfect candidate too!! fit every criterea
 
I'm not really sure that it's worth it to have this thread anywhere other than EADD, so I don't think we're going to try and keep it on the front page here. You might want to ask the EADD mods to merge your threads over there and then sticky the resulting mega-thread.
 
Hi,

I've not been on for a few days so have only just seen the messages that have been posted - thanks to everyone for their support. THe study is definately still running and I will PM people who have expressed an interest and are in or near london. I can travel to meet people if they aren't too far, but the USA (as nice as it would be!) is a bit far!

Also, if it is possible to keep this thread here that would be great - the one in the EADD is running a bit dry.

Thanks,

Justin
 
Hi, I just wanted to let you know that I am still looking for people who might be interested in taking part.

1. people who have never used drugs - as one of the control groups.

2. people who use drugs but do not use ketamine - as one of the control groups.

It takes 1.5 to 2hrs and involves computer tasks, questionnaires, giving a drug history and a urine sample.

You will be paid 15 pounds sterling.

Your participation is confidential, and anonymous.

Thanks, Justin
 
Hi,

Just to let you know that I am almost done, and am looking for some rather specific people to take part (so that my three groups match on different criteria!):

3 females (who have used drugs at least twice a month for at least a year, but don't use ketamine)

Aged 30 - 50yrs

With GCSE and/or A level education, but have not been to university


If you fit into either of these groups and are interested in helping me find out more about the longer term effects of ketamine, or just earning yourself 15 quid, please PM me, or email me on [email protected]

Thank you for reading.
 
Been away from the site a long time so I thought I would add a bit to this new forum. The following is a copy and paste from another forum where some of the UCL study's subjects came from. It isn't a detailed breakdown on the research, but it's an update.

Hi Everyone,

I just wanted to let you know that I have recently had my viva, which I passed. So I wanted to thank you all, again(!), for supporting my study into the effects of chronic ketamine use on semantic memory (which is like general knowledge) and subjective experiences.

Below is a copy of the abstract, which I hope will make sense to some of you. Please feel free to ask questions.

In a few days time I’m off on a long holiday to Thailand, which means that I won’t be checking these websites/email, so please don’t be offended if you contact me and I don’t respond for a while.

Once again, thank you, and best wishes,

Justin

Abstract

Background: There has been an increase in the prevalence of recreational ketamine use over the past five years. Due to ketamine’s cognitive and psychotomimetic effects it is being investigated as a pharmacological model for psychosis.

Problem under investigation: To investigate the long-term effects of chronic recreational ketamine use on indirect and direct semantic priming, general semantic processing and subjective experiences.

Participants: Forty-six participants, aged 18 to 46 years, completed the study, 24 male and 22 female.

Design: An independent groups design was used to compare three groups: 16 ketamine users (people who use ketamine and other recreational drugs), 14 poly-drug users (people who use recreational drugs, but not ketamine) and 16 non-drug users (people who have not and do not use illicit drugs). Participants completed computer tasks which assessed semantic memory and pen and paper questionnaires that assessed subjective experiences.

Results: The ketamine group scored higher than the non-drug group on a measure of schizotypy. Semantic processing was found to be similar across the groups, although the ketamine group had significantly longer reaction times to high frequency words than to low frequency words on the direct semantic priming task, whereas the two control groups showed no significant differences.

Conclusions: The ketamine group were impaired relative to the other two groups in their processing of high frequency words compared to low frequency words, and were higher in schizotypy than non-drug users. However, the absence of indirect priming effects across the three groups limits the conclusions that can be drawn and methodological reasons for this are discussed.

_________________
Justin Grayer
Trainee Clinical Psychologist
Sub-Department of Clinical Health Psychology,
University College London,
1-19 Torrington Place, WC1E 6BT



Not exactly the most suprising of results if you're a k user/addict yourself!
 
Could someone please explain indirect priming effect?
 
nuke said:
Could someone please explain indirect priming effect?
Semantic priming is the phenomena where the brain 'readies' itself when it comes across a particular word and expects that a related word will follow. As such, the semantic priming effect is usually measured in terms of reaction times. I'm not familiar with Justin's research, but if it's in any way like previous studies, he'll have been measuring reaction times to two such sets of words. Direct and indirect semantic priming are defined by the relationship between the two sets of words.

So, to illustrate the point, the classic example of direct semantic priming is where I say "tiger" (prime) and you react to the word "stripes" (target) quicker than any other word. The reason being that the prime word and the target word are directly related or associated.

Indirect semantic priming is a little different. The prime word isn't directly related to the target word. It's usually related via another word that isn't actually said out loud - something that I think is known as a mediator. With me so far? So, using the classical example above, I might say the word “lion” (prime) and you react to the word “stripes” (target) quicker than any other word. The reason being that although the prime and the target words aren't directly related or associated, they are connected through the unspoken and implicit word "tiger" (mediator).

What relevance the lack of an indirect priming effect has on his theory, only Justin would be able to explain.

Hope it helps.
 
Abstract

Background: There has been an increase in the prevalence of recreational ketamine use over the past five years. Due to ketamine’s cognitive and psychotomimetic effects it is being investigated as a pharmacological model for psychosis.

Problem under investigation: To investigate the long-term effects of chronic recreational ketamine use on indirect and direct semantic priming, general semantic processing and subjective experiences.

Participants: Forty-six participants, aged 18 to 46 years, completed the study, 24 male and 22 female.

Design: An independent groups design was used to compare three groups: 16 ketamine users (people who use ketamine and other recreational drugs), 14 poly-drug users (people who use recreational drugs, but not ketamine) and 16 non-drug users (people who have not and do not use illicit drugs). Participants completed computer tasks which assessed semantic memory and pen and paper questionnaires that assessed subjective experiences.

Results: The ketamine group scored higher than the non-drug group on a measure of schizotypy. Semantic processing was found to be similar across the groups, although the ketamine group had significantly longer reaction times to high frequency words than to low frequency words on the direct semantic priming task, whereas the two control groups showed no significant differences.

Conclusions: The ketamine group were impaired relative to the other two groups in their processing of high frequency words compared to low frequency words, and were higher in schizotypy than non-drug users. However, the absence of indirect priming effects across the three groups limits the conclusions that can be drawn and methodological reasons for this are discussed.

_________________
Justin Grayer
Trainee Clinical Psychologist
Sub-Department of Clinical Health Psychology,
University College London,
1-19 Torrington Place, WC1E 6BT
...
 
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