The trichotomy of man (or his trichotomous or tripartite nature) is the belief that man was created with three "parts" – body, soul, and spirit. This is a popular viewpoint among many Christians, but the official position of Catholicism (Catechism §365), not to mention the majority view of many Protestant traditions, is that man consists of only body and soul.
It turns out that there was some disagreement on this point in the early church. Apollinaris of Laodicea came up with a tripartite scheme in his attempts to explain the incarnation of Jesus, and he was defeated at the First Council of Constantinople (381). However, according to J. Oliver Buswell's Systematic Theology (3.2.5.H.2), his trichotomism was not specifically rejected – just his view of Christ's nature more generally.
Thus, I wonder – when did the church specifically reject the trichotomy of man? By "church" I'm referring to the orthodox (small O) church prior to the East-West schism, the Western church prior to the Reformation, and, if necessary, Roman Catholicism after that. Note too that this means I'm looking for official church councils, not the writings of respected fathers and doctors.