A probate conservatorship is a court proceeding where a judge appoints a responsible person (called a conservator) to care for another adult who cannot care for him/herself or his/her finances.
This page has information about how to establish a conservatorship, who can file, what duties and responsibilities are involved, and the different between "Conservator of the Person" and "Conservator of the Estate."
An LPS (mental health) conservatorship makes one adult responsible for a mentally ill adult. This type of conservatorship is only for adults with mental illnesses listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM).
An LPS conservatorship is only for people who are seriously mentally ill and need special care (usually placement in a locked facility and/or very powerful drugs to control behavior).
A limited conservatorship is a court proceeding where a judge gives a responsible person certain rights to care for another adult who has a developmental disability.
Generally, a person qualifies as developmentally disabled if s/he has an IQ less than 70 or is diagnosed with autism. Because developmentally disabled people can usually do many things on their own, a limited conservator has more limited powers than an LPS conservator.