469show a relationship between brain function changes during brief placebo treatment
and later side effects during treatment with medication. The fi ndings show the prom-
ise of new ways for assessing susceptibility to antidepressant side effects. The ability
to identify individuals who are at greatest risk of side effects would greatly improve
the success rate of antidepressant treatment. For example, physicians might select a
medication with a lower side-effect profi le, start medication at a lower dose or choose
psychotherapy alone when treating patients susceptible to antidepressant side effects.
A qEEG biomarker, the Antidepressant Treatment Response (ATR) index, has been
associated with outcomes of treatment with SSRIs in patients with MDD. In an open
study of norepinephrine reuptake inhibitor reboxetine, the ATR index predicted
response with 70.6 % sensitivity and 87.5 % specifi city, and remission with 87.5 %
sensitivity and 64.7 % specifi city (Caudill et al. 2014 ). These results suggest that the
ATR index may be a useful biomarker of clinical response during NRI treatment of
adults with MDD. Future studies are warranted to investigate further the potential util-
ity of the ATR index as a predictor of noradrenergic antidepressant treatment response.
Having a biological marker of likely treatment effectiveness to predict and guide
clinicians’ decisions would reduce the likelihood of unsuccessful treatments with
antidepressants. The PRISE-MD (Personalized Indicators for Predicting Response
to SSRI Treatment in Major Depression) study tested whether qEEG measures
taken after 1 week of treatment can predict effectiveness of a full treatment regimen
with antidepressant medications. The study, conducted by University of California,
Los Angeles, in collaboration with the US National Institute of Mental Health, was
completed but no results have been published as of end of 2014.
Individualization of SSRI Treatment
The introduction of the SSRIs (selective serotonin reuptake inhibitors) has
signifi cantly transformed the pharmacological treatment of several neuropsychiat-
ric disorders, particularly of individuals affected by depression, panic disorder,
obsessive-compulsive disorder and social phobia. Compared with the previous gen-
eration of psychotropic drugs, SSRIs offer an improved tolerability to therapy while
maintaining a high level of effi cacy. Nevertheless, despite these advantages, not all
patients benefi t from treatment; some do not respond adequately, while others may
Table 13.3 Biomarkers of response to antidepressant treatmentBiotechnology area Biomarkers
Brain imaging Rostral anterior cingulate cortex activity, hippocampal volume
Electrophysiology Quantitative EEG, REM sleep
Gene expression FK506-binding protein 5
Neuroendocrinology Dexamethasone/corticotropin-releasing hormone test
Pharmacodynamics SLC6A, 4HTR2A
Pharmacokinetics CYP, ABCB1
Proteomics/metabolomics BDNF, IGF-1, VEGF
© Jain PharmaBiotech
Psychopharmacogenetics/Psychopharmacodynamics