Why haven't we done an systematic investigation of drugs as means towards debiasing?

I have focussed my attention more on enhancing cognitive function more generally, which has some benefits with respect to debiasing but is far from explicitly targetted. There are some specific behavioural and psychological biases that I can target pharmaceutically but not all of them, not without combining drugs with training. Of course there is much that can be done to enhance the executive function, motivation and relaxed self awareness that makes training oneself out of biases much more viable.