Cannabis link to depression

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Cannabis link to depression

 

http://news.bbc.co.uk/2/hi/health/2498493.stm

 

The findings applied to heavy cannabis users

 

Frequent cannabis use can trigger depression, a study suggests.

Researchers have also found further evidence the drug can significantly

increase the risk of schizophrenia.

The risks are outlined in three papers in the latest issue of the British

Medical Journal.

 

 

Cannabis is not a risk-free drug. The public needs to understand the

potential dangers of triggering mental illness.

 

Cliff Prior, Rethink

Researchers say their findings highlight the need for measures to reduce

frequent and heavy use of cannabis.

The first paper, by doctors in Australia, found frequent cannabis use among

teenage girls in particular can trigger depression.

Their seven-year study of 1,600 teenage girls found girls who used the drug

everyday were five times more likely to become depressed and suffer from

anxiety compared to those who did not use the drug.

Those who used the drug at least once every week were twice as likely to

develop depression compared to non-users.

A second study, by doctors in Sweden, confirmed previous research suggesting

that cannabis can increase the risk of developing depression.

Their study of more than 50,000 men found those who had smoked the drug in

the late 1960s were 30% more likely to have developed schizophrenia.

The authors said their results suggested that as many as one in eight cases

of schizophrenia in the UK could be prevented by stopping people from using

cannabis.

The third study, by British scientists, suggests the risks of developing

schizophrenia are highest for those people who use the drug when they are a

teenager.

Their study of more than 1,000 people in their early twenties in New Zealand

suggested that one in 10 people who used cannabis as a teenager have since

been diagnosed with schizophrenia.

All of the researchers said the ill-effects were linked to cannabis and not

to any other drugs.

They also said there was little evidence to suggest that occasional use of

cannabis had a similar effect.

Further research

In an accompanying editorial Joseph Rey, professor of child and adolescent

psychiatry at the University of Sydney, said the studies backed up previous

research.

" These findings strengthen the argument that use of cannabis increases the

risk of schizophrenia and depression. "

But he added that further research is needed.

" Whether the use of cannabis triggers the onset of schizophrenia or

depression in otherwise vulnerable people or whether it actually causes

these conditions in non-predisposed people is not yet resolved. "

Education campaign

The UK charity Rethink, formerly the National Schizophrenia Fellowship, said

the findings highlighted the need for a public education campaign on the

risks of using cannabis.

Cliff Prior, its chief executive, said: " The research highlights how

cannabis can be one of the triggers for severe mental illnesses like

schizophrenia and depression.

" It shows why it is so important that more work of this kind is done so that

people with severe mental illness can have the best chance of recovering a

meaningful quality of life. "

He added: " Cannabis is not a risk-free drug. The public needs to understand

the potential dangers of triggering mental illness. "

Marjorie Wallace, chief executive of mental health charity SANE, added: " The

most worrying revelation of these studies is not just the immediate

triggering of hallucinations but that cannabis can lead to psychotic

symptoms and depression in later life. "

 

See also:

 

11 Nov 02 | Health

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06 Nov 02 | Health

Cannabis link to schizophrenia

 

30 Sep 02 | Health

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