Must an adaptive intervention recommend a single intervention component at each decision point?
No. An adaptive intervention can recommend a set of treatments (that is, more than just one). For example, the following two-stage adaptive intervention recommends either behavioral intervention or increasing the medication dose.
This type of adaptive intervention might result from clinical expertise, prior data or a randomized trial that suggests there is no evidence of a difference between increasing medication dose and adding behavioral intervention among non-responders to low-dose medication.