There's also the possibility of various types of neuroreceptor polymorphism. I've a dopamine receptor variant which is strongly linked to autism and ADHD, for example - and there are those who have serotonin receptor variants that which lead to a reduced sensitivity towards serotonergic psychedelics, or it may be due to a reduced expression of a serotonin receptor gene causing a relatively lower density of the relevant serotonin receptor.
Food for thought at least - and having an atypical neuroreceptor profile can itself be traumatising through behavioral divergences.
