Catechism of the Catholic Church §2091 — excerpt
The first commandment is also concerned with sins against hope, namely, despair and presumption: By despair, man ceases to hope for his personal salvation from God, for help in attaining it or for the forgiveness of his sins.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.