Researchers at the University of Aberdeen claim that smoking cannabis in pregnancy as well as taking certain prescribed medications would affect development of the fetal brain.

The researchers focused their work on the importance of molecules produced naturally in the brain and the way certain nerve cells recognize and connect with each other. They found that anything that affects this pattern could also affect brain functioning.

The brain molecules called endocannabinoids have been found to function in a similar way to tetrahydrocannabinol (THC) from cannabis, targeting the same receptors and signaling systems in the brain. For the brain to develop naturally, this signaling process needs to occur unhindered, its integrity must be maintained and not disrupted. If anything disrupted this process such as cannabis smoking or certain drugs that also interfere with the signaling system, it would ultimately affect the brain's functionality.

The researchers reported that their initial findings showed how important these naturally occurring molecules are in guiding the growth and connections of nerve cells in the developing brain. The next step was to demonstrate the extent of this signaling system and that complex network of neurons, crucial for higher cognitive functions, do not develop normally if endocannabinoid signalling was disturbed.

Cannabis is the most widely used drugs by women at reproductive age. While this study shows the negative effects of cannabis on brain development, previous studies showed that taking cannabis in pregnancy made children experience problems with physical activity.