Having worked in the field, ANY substance of abuse is a gateway drug. The population of DC should consist of elected officials (IOW, in state-owned housing) and foreign nationals residing in embassies, and no one else.
I too have worked in the field with PTSD and child abuse victims. The base cause of addiction is severe emotional pain, occasionally physical pain. Thus, any pain killer is potentially addictive, however, cigarettes and alcohol (being legal) are usually the gateway substances. I have found the most effective treatment is a combination of really good nutrition including supplements and intense emotional discharge of the traumatic incidents of the past and sometimes the present.
Regarding DC, it is proposed that only the small ceremonial central areas like the Mall, the monuments, Congress, Supreme Court, White House, museums and other nearby government buildings be called DC. The rest of the city where the 650,000 people live should become a state since that is more people than Wyoming and Vermont.
They shouldn’t have to worry every time Congress talks about shutting down the government that they can’t even spend their own DC tax money to pick up the garbage, renew a drivers license, get a marriage license and other basic services. Wouldn’t you be up in arms at that treatment?