No we all have these genes --we must have them for survival.
This is why I say it gets complex---bdnf --gene is found in more than the brain -- however its s secret protein or nerve growth for the brain. Its about increase these level of bdnf---low level indicates in other disease as well ocd,alheimzers,hunnington and dementia ---this is where i indicated before the studies in depression decrease in the bdnf gene to the hippcampus to shrink --hence stress and depression decrease expression of bdnf. taking anit dep meds,exerise,other therapy increase its level of the bdnf level.