This is false. Plenty of studies have shown that it stimulates neurogenesis in the brain to help form healthier pathways and connections for recovery from depression and anxiety. AKA a damaged brain. Similarly, the reason SSRIs work when prescribed for depression is not due to increases in dopamine, norepinephrine, or serotonin. But instead, these neurological chemical balances stimulate neurogenesis in the same parts of the brain that THC and CBD do. Science still doesn't know how antidepressants do it. What is certain is that antidepressants have a high likelihood for dependence and getting off of them can be very tricky and in some cases impossible for the person being prescribed. Cannabis however, you can just stop without major negative consequences. I.e., cannabis is not physically addictive, and is a safer alternative between the two, and uneducated statements and perspectives like the above quote allows for continuing profit by big pharma with sub par success in patients, and keeping solutions that they would make less money off of, such as cannabis, locked away under strong stigma against it.
Weed only began to be viewed as harmful during political effort to suppress Mexican-Americans in the early 1900s. I.e.... racism.