Using primary care data from the IQVIA Medical Research Database (IMRD-UK), researchers from the University of Birmingham Institute of Mental Health and the Institute for Applied Health Research suggest in a new study that, after the first Registered cannabis use, patients are three times more likely to develop common mental health problems such as depression and anxiety .
In addition, they were almost seven times more likely to develop serious mental illnesses such as psychosis or schizophrenia . Cannabis users also had much higher rates of having a recorded history of using other drugs such as heroin, cocaine, and amphetamines.
You have to act with caution
The dataset included records from 787 GP visits in the UK collected over a 23-year period between 1995 and 2018. The researchers were able to include data from 28,218 patients who had a recorded exposure to cannabis. These were matched with 56,208 patients who had not used cannabis and controlled for sex, age, ethnic origin, smoking, and other relevant characteristics .
While the links between cannabis use and serious mental illnesses such as schizophrenia and psychosis are well researched, the associations are less clear between cannabis use as described in the patient’s GP records and other types. common mental illnesses such as depression and anxiety. According to Clara Humpston , lead author of the study:
Cannabis is often considered to be one of the ‘safest’ drugs and has also shown promise in medical therapies, prompting calls for its legalization globally. Although we cannot establish a direct causal relationship, our findings suggest that we must continue to exercise caution, as the notion that cannabis is a safe drug may be wrong.