One variation of a method includes: accessing a first timeseries of biosignal data collected by a wearable device worn by a user during a first time period; deriving a first insomnia profile, representative of a set of health indicators exhibited by the user during the first time period, based on the first timeseries of biosignal data; and selecting a treatment pathway for implementation by the user based on the first insomnia profile. The method further includes: accessing a second timeseries of biosignal data collected for the user by the wearable device during a second time period; deriving a second insomnia profile, representative of the set of health indicators exhibited by the user during the second time period, based on the second timeseries of biosignal data; and characterizing effectiveness of the treatment pathway based on a difference between the first insomnia profile and the second insomnia profile.