A Systematic Review to Determine if Family History of Response to Medication Predicts Outcome in Mood Disorders.

Purpose/background: Examining a patient's family history of medication response is a commonly used method to inform treatment selection. Though widely recommended, there are no published reviews that assess the validity of this approach when treating patients with affective disorders.

Methods/procedures: All published studies in the form of case-control or randomized controlled trials that enrolled probands with either bipolar I or II depression or major depression and were written in English were included. Studies must have also included biological relatives and must have included at least 2 families. The authors compared the methodology of each trial to a hierarchy of study designs best suited to demonstrate the predictive ability of a family history of response to a medication.

Findings/results: All studies involved only a small number of participants and none of the publications included in this review used a study design that reached the highest level of study quality needed to prove the link between 2 family members' likelihood of response to a medicine. Two studies had some elements of a level I study while the remaining studies were classified at level II or III of the study hierarchy.

Implications/conclusions: Although small studies suggest that a family history of drug response can predict outcome in mood disorder patients, the designs of these studies do not confirm this in a definitive manner.