A doctor’s opinion is not necessary to establish lack of capacity. Indeed, a diagnosis of a mental or physical disorder is not, by itself, sufficient evidence for a finding that one lacks the legal capacity to contract, convey, marry, make medical decisions, and so forth. Prob C §810. Nevertheless, a doctor’s opinion is persuasive evidence, especially if the petitioner can correlate it with the proposed conservatee’s behavior. For example, if the proposed conservatee is diagnosed with anxiety and depression (see Prob C §811(a)(4)), the petitioner should illustrate the effect of the disorder on the proposed conservatee’s ability to make decisions.