(949) 394-0607

It seems marijuana does affect long term memory.  It seems to affect it for a great length of time actually.  A new study published by JAMA Internal Medicine shows it actually shrinks middle aged adults’ vocabulary if they were regular teenage users.  Even if they’ve quit for years, it still seems to have a negative result.  For those who have continued using regularly since adolescence into middle age, the results are even worse.


People who smoke regularly have a reputation for being “slower,” and this is apparently based on fact.  Current users are slower in processing, and have a reduced vocabulary.


Those who have used since being a teenager, and continue to use into adulthood have slower processing, reduced vocabulary, and poorer executive functioning (Executive functioning is essentially the planning out and completing of a task or set of tasks.  For example, deciding to first brush teeth, then comb hair, then apply make-up, and then following the planned out steps).


There were a couple of things about this study that really give it legitimacy.  First of all, people across all strata of life participated.  There were people of different races, sex, and socioeconomic status.  Secondly, the study finished with over 3,000 participants.  I used to teach statistics at Vanguard University.  One of the first things I taught students was that a sample needed a minimum of 30 participants to have statistical significance.  A study with over 3,000 participants from start to finish is a HUGE sample size.


It’s important to understand what marijuana does to the brain because many teenagers see it as harmless.  They don’t associate it with other drugs, and some even think of it as “natural.”  There’s such big push it eat naturally these days, that a lot of people assume everything “natural” is healthy.  This simply is not true.  Just because marijuana is a plant doesn’t mean it is okay to use.  A lot of cannabis plants are genetically modified anyhow.


If you’d like to read more about this study, you can check out:


Helping teens grow and families improve connection,

Lauren Goodman, MS, MFT