Group sessions and two brief sessions both cut marijuana use more than waiting.

The study

1. 01

   Who took part

   291 adults who asked for help with marijuana use in the Seattle area of the USA. Their average age was 34, 77% were men and 95% were white.

2. 02

   What they did

   One group had 14 two-hour sessions over 18 weeks, weekly at first and then every other week. Another had two 90-minute one-to-one sessions a month apart, with advice and a talk-based method that draws out reasons to change. A third group waited four months before they were offered treatment.

3. 03

   What happened

   At 4 months, the group programme had about 7 marijuana days a month, and the two-session group about 8. The waiting group had about 17, and at one month the two-session group had lower use. After that, the two treatments did not differ.

What the study found

1. Helped

   Group sessions led to fewer days of marijuana use than waiting four months did.

   • Rule: Write down when and wheretested

   Randomised trial of 291 adults seeking treatment for marijuana use · vs people who waited four months for treatment · they rated themselves · ⚠ summary claims more than the results show

2. Helped

   Two individual sessions cut marijuana use more than waiting four months did.

   • Rule: Write down when and wheretested

   Randomised trial of 291 adults seeking treatment for marijuana use · vs people who waited four months for treatment · they rated themselves · ⚠ summary claims more than the results show

3. Mixed

   Group and two-session treatments matched at four months, but two sessions gave lower use at one month.

   • Rule: Practise with a grouptested

   Randomised trial of 291 adults seeking treatment for marijuana use · vs people who had two one-to-one sessions · they rated themselves · ⚠ summary claims more than the results show

Source