Yup. Christian Prayer also doesn’t repeat the antiphons (I’ve always wondered why–they aren’t that long).
Repeating the antiphon is optional:
- At the beginning of each psalm its own antiphon is always to be recited, as noted in nos. 113-120. At the end of the psalm the practice of concluding with the Glory to the Father and As it was in the beginning is retained. This is the fitting conclusion endorsed by tradition and it gives to Old Testament prayer a note of praise and a Christological and Trinitarian sense. The antiphon may be repeated at the end of the psalm.
(from the General Instructions of the Liturgy of the Hours; bold is mine)
In the community I’m affiliated with, if the antiphon is sung (always in Latin) it is repeated as musically the mode of the antiphon is designed to set the psalm tone and the finale of the psalmody is meant to blend into the mode of the antiphon.
When they recite the psalmody recto-tono (in monotone, as is done at Vigils and the minor hours), they don’t repeat the antiphon at the end. Compline, in the monastic tradition, is chanted without antiphon “in directum”. I’m guessing in Christian Prayer, most folks are reciting so it isn’t really necessary to repeat the antiphon. If the Office is being sung or chanted, probably they’ll be using some other book with musical notation (such as the Mudelein Psalter in English, Les Heures Grégoriennes in French, or for a community, they probably have printed their own books with the music, or at least an antiphonary of sorts with the antiphons and psalm tones). Outside communities and cathedral chapters, I very much doubt the Office is sung or chanted very often.
Historically, at the start of a psalm, only the first part of the antiphon was intoned by the cantor when chanting in community (up to the * in the antiphon), the cantor would then chant the first hemistich of the first verse, then his side of the choir would chant the second hemistich, then the entire community would chant the psalm alternating both sides of the choir, and after the Gloria Patri, the antiphon would be sung by all in full.
In the 1950s under the reign of Pius XII, this practice was changed: the cantor would intone the antiphon up to the “*”, and the choir and cantor would complete it, then begins the psalmody: the cantor intones the first hemistich, and his side of the choir does the second hemistich, then the other side of the choir picks up the next verse, alternating until the Gloria Patri. Then the entire choir repeats the antiphon. This is the current practice.