"human rights" or some other random UN declaration
Wait what.
Assuming you're being sarcastic- could you point out where people can't get therapy of any sort unless they want it?
Article 18:
Everyone has the right to freedom of thought, conscience and religion;
Article 19:
Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.
In other words, the state can't force you to change your mind and any state who does forcibly admit someone to a mental hospital is in direct violation of the declaration of human rights. Note that article 19 also means that anyone is free to give a prisoner detailed escape plans...
On a similarly absurd note:
Article 17
Everyone has the right to own property alone as well as in association with others.
No one shall be arbitrarily deprived of his property.
In other words, the state can't prevent a convicted criminal from earning money and taking a convicted criminal's possessions is also pretty difficult because you have to prove that they were related to the crime. A criminal who happens to own a track of land that he rents to others will get the benefits of that land even if he's locked away for life.
And article 21:
Article 21
Everyone has the right to take part in the government of their country, directly or through freely chosen representatives.
Everyone has the right of equal access to public service in their country.
The will of the people shall be the basis of the authority of government; this will shall be expressed in periodic and genuine elections which shall be by universal and equal suffrage and shall be held by secret vote or by equivalent free voting procedures.
This means that a convicted murderer can become head of state, even if he's still serving jail time.