Study Design: This was an 8 week, blinded, multi-center, randomized controlled trial of 1,167 subjects with major depressive disorder from 20 academic sites and 40 community sites. The trial was unblinded after the 8 week check-in, and the subjects were followed out to 24 weeks. The study assessed the impact of the GeneSight Psychotropic test on psychiatric treatment response compared to treatment as usual (TAU). The raters used the Hamilton Rating Scale for Depression (HAM-D17), and the subjects had to have a minimum score of 14 in order to be eligible for the study.

Study Endpoints: GUIDED compared two active treatment arms. The primary endpoint was symptom improvement with secondary endpoints of response and remission. Symptom improvement is defined as the change in HAM-D17 score, and this is based on the group average. Response is defined as a ≥50% reduction in HAM-D17 score, and remission is defined as a HAM-D17 score ≤7.

Study Limitations: The treating clinician was not blinded to study arm, the majority of the cohort was Caucasian, the primary results may not be generalizable for patients with mild depression, and the impact of polypharmacy on patient outcomes was not evaluated.