(Reuters) - People who suffer an episode of psychotic symptoms may want to steer clear of marijuana afterwards, according to a study from the Netherlands.
Researchers, whose findings appeared in the Journal of Clinical Psychiatry, found that people who kept smoking cannabis after a psychotic break tended to have certain problems in recovery.
The effects were fairly small and seemed to be limited to social life and financial independence, rather than mental health symptoms. But the findings did support conventional wisdom that people who have ever suffered from psychosis should avoid smoking marijuana.
"I would advise patients who've suffered from a psychosis and still use cannabis to stop using it," said lead researcher Gunnar Faber, of Yulius Mental Health Institute in Dordrecht, the Netherlands.
"The message is clear that marijuana is not helping people with a history of psychosis," he told Reuters Health by email.
Studies have linked heavy marijuana use to a higher-than-normal risk of having a first episode of psychosis, which usually features hallucinations and delusions, but it hasn't been clear whether people who continue using the drug after a psychotic break have a tougher time recovering.
For the new study, researchers looked at 124 people who had been part of a clinical trial testing the effects of longer-term treatment with antipsychotic medication. All had gone on treatment after a first-time episode of psychotic symptoms.
As part of that trial, the patients were asked about marijuana use. Overall, 21 percent continued smoking cannabis during the two-year study -- and 35 percent had used the drug before.
By the end of the trial, 53 percent of study participants had seen their psychotic symptoms go away, with marijuana users just as likely as non-users to recover. They also had as good a chance of "clinical recovery," which meant their symptoms were gone and their daily functioning was back to normal, or close to it.
About one-fifth of all patients had a clinical recovery.
Still, cannabis users did show an increased risk of certain "social" problems, scoring lower on questionnaires gauging financial independence and social activities.
"In real life, this could mean that continuing cannabis use has a detrimental effect on social functioning," Faber said.
He noted, though, that any effects would vary from one user to another -- and the findings don't necessarily mean that marijuana itself caused the social problems.
Few marijuana users in the study used it heavily, which may help explain why the habit did not seem to have strong effects on recovery, he said.
It's possible that continued marijuana smoking keeps some users from working or going out, though less work and less play might feed people's use, Faber said. Or perhaps some other factor altogether could explain the connection.
Still, the bottom line is that it's best for people being treated for psychosis to avoid, he said. SOURCE: bit.ly/z1L1BL
Reporting from New York by Amy Norton at Reuters Health; editing by Elaine Lies