KESKUSTELU

Syy-yhteys näkyisi aivan varmasti kannabiksen lisääntyneen käytön ja skitsofrenian esiintyvyyden välillä JOS sellaista olisi.

Vaikka kannabista käyttäneillä on em. tutkimuksen mukaan suurempi todennäköisyys sairastua skitsofreniaan, ei se tarkoita sitä että kannabis olisi aiheuttanut sairastumisen.

Acute mood effects
Adverse mood effects can occur, particularly in inexperienced users, after large doses
of cannabis. Anxiety and paranoia are the most common of these effects, which also
include depersonalisation, panic, dysphoria (unpleasant mood), depression, delusions,
illusions and hallucinations. These effects normally disappear a few hours after cessation
of use and are responsive to reassurance and a supportive environment (Adams and
Martin, 1996; Joy et al., 1999).

Cannabis and psychosis
There is evidence that large doses of THC can produce an acute psychosis marked
by confusion, amnesia, delusions, hallucinations, anxiety, agitation and hypomanic
symptoms. Nonetheless, such high THC doses are rare among cannabis smokers,
given that they are likely to stop smoking if they experience undesired effects. Cases do
exist, however, of high doses following ingestion of cannabis (cannabis cookies, space
cake), where the user has less immediate control over THC titration. Such reactions may
also occur after heavy cannabis use, or in some instances, after acute cannabis use by
sensitive/vulnerable individuals. These effects abate rapidly after discontinuing cannabis
use. There is little evidence that cannabis alone produces a psychosis that persists after
the period of intoxication in non-vulnerable cannabis users (Joy et al., 1999; Hall and
Degenhardt, 2000).

Cannabis has been found to have an adverse effect on the clinical course of
schizophrenia. In a Dutch prospective study which assessed patients each month over
a year, the 24 people in the cannabis-using group had significantly earlier psychotic
relapses than the non-cannabis-using group, an effect that was dose-related (Linszen et
al., 1994).

A study of cannabis use and psychotic symptoms at age 18 in a cohort of 3 500
Greek adolescents found positive associations between frequency of cannabis use and
psychotic experiences after controlling for other drug use and depressive symptoms in
the statistical analysis, with a stronger association for those who started their cannabis
use before age 15. However, the rates of cannabis use in the study group was low, with
6 % reporting lifetime cannabis use and 0.9 % reporting daily or near-daily use (Stefanis
et al., 2004).

Four main views on the nature of this association have been proposed. Firstly, the
link may be due to socio-demographic, economic or genetic factors common to both
substance use and schizophrenia. Secondly, the self-medication hypothesis suggests
that patients with schizophrenia may be using cannabis and other drugs as a form of
self-treatment for their condition. Thirdly, some suggest that cannabis causes psychosis.
Finally, the vulnerability hypothesis proposes that the use of cannabis can increase the
risk of schizophrenia among people with a predisposition to the illness.

The Swedish conscript study
A 15-year prospective study of cannabis use and schizophrenia in 50 465 Swedish
military conscripts was the first study to report a potential link between cannabis use
and later schizophrenia. The study recruited conscripts who were 18–20 years old in
1969–70. Conscripts who were hospitalised for schizophrenia or psychosis and could
be linked to their military medical records were identified. Through this linkage, the
relationship between cannabis use and the onset of schizophrenia might be established.
The relative risk for a diagnosis of schizophrenia was 1.3 times higher for those who
had used cannabis 1–10 times, three times higher for those who had used cannabis
1–50 times and six times higher for heavy users of cannabis (defined as use on more
than 50 occasions) than among those who had not used cannabis. However, over half
of the heavy users had had a diagnosis of a psychiatric condition other than psychosis
at conscription and when the analysis took this factor into account the relative risk fell to
2.3 (Andreasson et al., 1987; Allebeck, 1991).
A follow-up of the conscripts reported in 2002. Again, heavy cannabis users were found
to be 6.7 times more likely than non-users to be at risk of a diagnosis of schizophrenia
after 27 years. The risk held when the analysis was carried out on a subsample of
conscripts who had used cannabis only. While not an exhaustive array, when other
possible confounding factors such as psychiatric diagnosis at conscription, IQ, growing
up in a city and cigarette smoking were taken into account the risk, though reduced, still
remained, with heavy cannabis users having a threefold relative risk of a diagnosis of
schizophrenia (Zammit et al., 2002).

Alkoholi ei aiheuta skitsofreniaa ja todennäisesti sellaiset jotka käyttävät kannabista päivittäin, käyttävät myös alkoholia ja sen lisäksi esim. amfetamiinia, LSD:tä tai heroiinia.

Lisää "uskovaisten" kannalta ikävää tietoa kannabiksesta ja skitsofreniasta.

Miksi meillä kuitenkin puhutaan vain jostain kannabiksen riskimarginaalista, kun samaan aikaan altistetaan jopa lapsia lääkkeiden hengenvaarallisille sivuvaikutuksille?

Brittiläinen psykofarmakologian tutkija David Healy syötti Prozacia kahdellekymmenelle terveelle ihmiselle, minkä tuloksena kaksi koehenkilöä vajosi itsetuhoiseen masennukseen. Kaksi kahdestakymmenestä tarkoittaa yksi kymmenestä, eli 10 % käyttäjistä.

Kannabis on laiton huumausaine, vaikka yliopistojen "ikiopiskelijatupruttelijat" lahjakkaasti sen unohtavat!

Acedia, empiiristä tutkimusta on suoritettu 30 vuotta Hollannissa.