Long v. Wilkie, No. 16-1537(Argued August 28, 2019 Decided December 30, 2020); referral for extraschedular consideration; 38 C.F.R. § 3.321(b)(1); “exceptional” or “unusual” disability; symptoms that may prove exceptional, Doucette, 28 Vet.App. at 371; “rating schedule must be deemed inadequate before extraschedular consideration is warranted.” Sowers v. McDonald, 27 Vet.App. 472, 478 (2016); a valid DSM-5 diagnosis is required to compensate a psychiatric disability, Martinez-Bodon v. Wilkie, 32 Vet.App. 393, 404 (2020); linkage between the alleged complaint and an underlying disability, King v. Shulkin, 29 Vet.App. 174, 182 (2017);