Review article

Predictors of response in depression

Clinical predictors

Great strides have been made in the past decades in one significant area that aids in predicting response to treatment: diagnostic specificity. With each revision of the Diagnostic and Statistical Manual, 4th edition [5], diagnoses have become more specific and more useful in guiding treatment choices. Depression is no longer thought of as one illness but as a syndrome appearing in many contexts: major depression, dysthymia, bipolar disorder, schizoaffective disorder, substance-induced mood

Demographic predictors

In a study of lithium augmentation of TCA-resistant depressed patients, age and sex were not related to treatment outcome [16]. In a study of 60 depressed outpatients who received 4 months of antidepressant treatment, those who remitted (60% of subjects) were significantly older and more likely to be married.

Men and women have been found in some studies to respond differently to antidepressants, suggesting that gender might be predictive of response in some cases. In some studies, men have

Physiologic predictors

Physiologic correlates of serotonergic or noradrenergic abnormalities have been postulated to predict response to agents affecting these neurotransmitter systems. In a study by Gallinat et al [40], the pattern of auditory evoked potentials was found to be correlated to response to serotonergic agonists. Measuring the loudness dependency of late auditory evoked potentials, the researchers found that a strong response at baseline was related to significantly greater decrease in depressive

Biochemical and endocrinologic predictors

Historically, the dexamethasone suppression test was developed to assist in the diagnosis of depression. In the presence of exogenous glucocorticoid, serum cortisol normally is suppressed by a negative feedback mechanism of the hypothalamic-pituitary-adrenal axis; depressed patients have been described as nonsuppressors because their cortisol levels fail to suppress after administration of dexamethasone. The dexamethasone suppression test has also been studied as a predictor of treatment

Psychologic predictors

Various factors, such as temperament, character, and perceived parental care, have been examined as potential risk factors for depression; more recently, studies have also investigated the role of such factors in predicting the outcome of depression with adequate treatment. Using Cloninger's theory of personality to study 86 consecutive patients with major depression in a 16-week open trial of maprotiline, Sato et al [60] suggest that character dimensions, such as cooperativeness and

Neuroanatomic predictors

Advances in neuroimaging and recent neurobiologic models of depression are being applied to predicting treatment response. Studies using methodologies, such as multichannel EEG and positron emission tomography, have indicated that baseline activity in the rostral region of the anterior cingulate cortex predicts response to depression [63], [64]. Pizzagalli et al [64] recorded 28-channel EEGs from depressed patients and controls; patients were then treated with nortriptyline and after 4 to 6

Summary

Conflicting or sparse data on predictors of treatment response in depression have resulted in lack of clear guidelines in choosing antidepressant treatment. Critical to treatment outcome are accurate diagnosis and adequate treatment. Other data easy to obtain, such as age, gender, and marital status, have failed to be consistent predictors; more elaborate studies, such as receptor analysis or neuroimaging, are not yet accessible to most clinicians or economically feasible; however, they offer