Early pot smoking, depression may be linked

[onlyecig]

Overall, the researchers found a modest association between marijuana smoking before the age of 17 and the odds of suffering depression later on. Across the countries, early marijuana use was linked to a 50 percent increase in the risk of developing a depression "spell" after age 17.

The strength of the marijuana-depression link did weaken, however, when the investigators factored in childhood conduct problems -- like skipping school, getting into fights and shoplifting.

Unfortunately, de Graaf said, he and his colleagues lacked information on conduct problems from study participants in certain countries -- including some of those nations where the connection between early pot use and depression was strongest, such as New Zealand and South Africa.

So the full extent to which childhood behavioral problems may explain the pot-depression link is not clear.

The study has other key limitations as well. One is that participants were surveyed at a single point rather than followed over time, which is the best way to gauge which came first -- the drug use or the depression.

Instead, the study participants were screened for depression "spells" -- persistent feelings of sadness and other symptoms, such as appetite changes and sleep problems, that lasted for at least two weeks -- then asked to recall when they had first started having such episodes.

Those who said they were 17 or older when their depression first hit were considered "cases." Across the countries, 9,647 participants met that definition and were compared with the 41,000-plus men and women who had no current or past depression.

Still, de Graaf said, it is possible that as with other substances, such as alcohol, children's and teenagers' still-developing brains may be more vulnerable to any direct toxic effects of marijuana use.

More studies are still needed, however, according to de Graaf -- particularly ones that follow young people over time to see whether marijuana use does precede the development of mental health problems in some kids.