What is the test for psychological detention?

The concept of psychological detention first arose in Regina v. Therens (1985), 1985 CanLII 29 (SCC), 18 C.C.C. (3d) 481 (S.C.C.), where it was held that there must be a demand from the police, coupled with a reasonable belief on the part of the accused that there is no option but to comply with that demand. The testimony of an accused is usually the basis for establishing this belief. However, the determination is ultimately objective, so that there are cases where courts have concluded that the accused was psychologically detained even though he did not testify.