Does genetically guided antidepressant prescribing improve outcomes in depression?

INTERVENTION: Pharmacogenetic treatment algorithm and report to guide antidepressant dosing. [1] a) Patients give a buccal brush sample for DNA analysis of polymorphisms implicated in pharmacokinetic pathways b) the algorithm provides guidance on the dosing of the antidepressant, type of antidepressant is at clinical discretion c) any commonly used oral antidepressant currently PBS approved for treatment of major depression can be administered. d) treatment phase of the study is 12 weeks with daily medication dosing [2] Compliance to medication is based on patient report to their prescriber and pharmacy collection of medication. CONDITION: Major Depression PRIMARY OUTCOME: Remission from major depression, a score of 7 or less on the 17‐item Hamilton Depression Rating Scale SECONDARY OUTCOME: Medication Tolerability. This is assessed by patient report of side effect to their prescriber, and if the side effects is so bothersome to the patient that the prescriber reduced the dose or ceases the antidepressant this will be noted as a medication tolerability problem. Transit or persisting side effects not so bothersome to lead to dose reduction or cessation will not be considered a clinically relevant tolerability issues. INCLUSION CRITERIA: Principal Diagnosis Major Depression Requires antidepressant treatment clinically