Yes, but also often are not actively in control of them.
People are also in control of whether or not they gamble their last dollar instead of buying some food, or whether or not they put that needle into their veins.
History has shown human nature can be dangerously out of control and people will happily destroy their own lives given the opportunity.
Therefore society tries to protect those vulnerable people with legislation.
Thats why we have voting and a legal system which builds upon previous laws. You and I do not need to decide where the line in the sand is drawn, the majority of the population does that via the political and legal framework society has created.
Do you think "murder should be legal" is a popular position?
Never met a narcicist?