Cannabis results in poor memory and abnormal brain structures

Many people argue that cannabis is a relatively safe drug. Overdosing is almost impossible and there are few cases of long-term problems; however, new research has shown that cannabis alters the brain in a negative way, reducing memory and causing the creation of abnormal brain structures.

Researchers looked at a small group of people who once had a cannabis use disorder and carried out memory tests and brain scans. This group was compared to a control group of people who had never used cannabis. A cannabis use disorder, or cannabis dependence, is when people develop a daily, or very frequent, dependence on cannabis that affects their normal social function.

The results of the tests were also compared with people with schizophrenia and with people with schizophrenia who had additionally once had a cannabis use disorder.

The study found that people who have used cannabis in the past showed changed in certain parts of the brain. The changes were similar for both people with and without schizophrenia.

Some of the changes in the brain are linked with working memory scores and also with the age when cannabis use started.

The study was limited in that it only examined brains at a single point in time; therefore, there is no way to be sure if the brain changes occurred after cannabis was used or were always present.

The study was carried out by Washington University and Northwestern University Feinberg School of Medicine in the US and was funded by the National Institute on Drug Abuse, US National Institute of Mental Health, the Warren Wright Adolescent Center at Northwestern Memorial Hospital Stone Institute of Psychiatry, and the Office of National Drug Control Policy. The research paper was published in the journal Schizophrenia Bulletin.

There is a current trend to make cannabis legal; however, there is a known connection between cannabis use and mental health problems.