Quantitative Measurement in Psychiatry and Personalized Medicine

In most areas of medicine objective measurement plays a key role in diagnosis and clinical decision-making. Blood tests, ECG’s, blood pressure determination, x-rays, biopsies, etc. are used routinely in this context. In psychiatry, on the other hand, measurement is often qualitative rather than quantitative. Although some would argue that psychopathology by its nature does not lend itself to measurement, there is a strong scientific tradition of measurement in the development, testing and regulatory approval of psychopharmacologic agents, as well as in clinical treatment research in general.

There is another area in which measurement is rarely used, but could provide important information for clinical decision-making and that involves therapeutic drug monitoring (TDM). Both of these tools are grossly underutilized in the clinical practice of psychiatry. 

An important study involving measurement-based decision-making in the treatment of depression was recently reported.¹ Although there is a strong rational for measurement-based care, few studies have examined its impact and there has never been a randomized controlled trial with blind raters comparing measurement-based care with usual treatment in the management of depression. The aim of this study was to determine the efficacy and safety of measurement-based care in patients with major depression.

The investigators hypothesized that time to response and time to remission would be significantly shorter in the measurement- based care group, without greater side effects or discontinuation, in comparison to the standard treatment group. Out patients with moderate to severe major depression were randomized to 24 weeks of either measurement-based care (guideline- and rating scale- based decisions; N=61), or standard treatment (clinicians’ choice decisions; N=59). Pharmacotherapy was restricted to paroxetine (20–60 mg/day) or mirtazapine (15–45 mg/day) in both groups. Depressive symptoms were measured with the Hamilton Depression Rating Scale (HAM-D) and the Quick Inventory of Depressive Symptomatology–Self-Report (QIDS-SR). Time to response (a decrease of at least 50% in HAM-D score) and remission (a HAM-D score of 7 or less) were the primary endpoints. Outcomes were evaluated by raters who were blind to study protocol and treatment.