Does marjuana specifically thc cause brain damage , drop in iq and how long does this last from smoking a thc vaporizer?

When you give in to the addictive aspects of our natures and preoccupy yourself with the temporary euphoria or pleasures of the drug, you are not focusing on moving your young life forwards to achieve the ideal life goals that can make you a useful member of society and discover the real meaning of life. That looks like low IQ. You can stop it with will power. Ephesians 4:22-24

Use of marijuana has been linked to cognitive and emotional issues, specifically in adolescence and early 20's. This may not necessarily be reversible. This can be objectified by Neuropsychological Testing. Appropriate therapies may help future coping. Suggest proactive approach and future avoidance of all recreational drugs.