The Holy See really should consider clearly separating the two causes for early resignation foreseen in can 401 § 2 of the Code of Canon Law - disease or "other grave reason" (and here, other grave reason should be further classified in personal or doctrinal reasons), as a matter of justice, so that those who do resign for health reasons are not tainted by association with those who resign for other reasons...
The Holy Father, Benedict XVI, has accepted the resignation to pastoral government of the diocese of Liepāja (Latvia), presented by H.E. Bp. Wilhelms [Vilhelms] Lapelis, O.P., in conformity with can. 401 § 2 of the Code of Canon Law. [Bollettino]
In his own letter to his Diocese, the Bishop Emeritus, who is 50 years old, does not at all imply a disease, but says he is "pleased" with the Papal decision because he sees in it "the will of God". So we are just left wondering...