According to a recent study by University of Pensylvannia scientists, there were
small or limited associations between [adolescent] cannabis use and structural brain measures. But even calling the effect small is aggrandizing harms. Their data didn’t support the notion that teens using cannabis causes any changes in the developing brain.
Preclinical studies are supposed to provide precise, controllable, and translational models for human diseases. But the manipulations that researchers use — like injecting a precise dose of THC into a rat — may sometimes miss important points. What if smoking and injection have different effects? How might this bias results? University of Florida researchers asked just that question, studying the effects of injected vs. smoked THC in rats. Injecting low doses of THC impaired memory.
THC and other cannabinoids are known to induce neurogenesis — the creation of new neurons — in the brain. There are reasons to believe that this can positively influence diseases like dementia or traumatic brain injury, as well as the ability to learn. Malaysian researchers recently probed the question, does THC improve cognition by inducing neurogenesis? Yes, but only at the right dose.
In a shorthand that drives scientists mad, serotonin is often called ‘the neurotransmitter of happiness.’ This tag is especially troublesome as more and more flaws become apparent in the ‘serotonin hypothesis’ of depression – the idea that depression is caused by a serotonin deficit, which a pill (a serotonin reuptake inhibitor) could correct.1 Serotonin is a complex molecule in the brain and the periphery with a vast and intricate