Mechanisms of Antidepressant Non-Response in Late-Life Depression

Our target is depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD). The HRSD is a 24-item questionnaire used as an indication of depression and a guide to evaluate recovery. Total scores range from 0-74, not including atypical symptoms sub-scale. A score of 16 or above is typically considered to indicate the presence of depressive symptoms. Higher scores indicate greater severity.

Our target is depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD). The HRSD is a 24-item questionnaire used as an indication of depression and a guide to evaluate recovery. Total scores range from 0-74, not including atypical symptoms sub-scale. A score of 16 or above is typically considered to indicate the presence of depressive symptoms. Higher scores indicate greater severity.

QIDS-SR is a 16 item scale self-report form that was used to measure depression outcomes. This self-report is valuable in this study, because it is less susceptible to clinician and rater bias. The QIDS-SR has been increasingly used in antidepressant studies due to its equivalent weightings for each symptom item, clearly understandable anchor points, and inclusion of all DSM criteria for depression. The scores range from 0-27 with 27 being worse depressive symptoms.

QIDS-SR is a 16 item scale self-report form that was used to measure depression outcomes. This self-report is valuable in this study, because it is less susceptible to clinician and rater bias. The QIDS-SR has been increasingly used in antidepressant studies due to its equivalent weightings for each symptom item, clearly understandable anchor points, and inclusion of all DSM criteria for depression. The scores range from 0-27 with 27 being worse depressive symptoms.

CES is an 8 item scale in which subjects rate their impression of the credibility of the treatment and how they estimate their expectation of improvement. The CES is the most widely used measure of expectancy and has demonstrated good psychometric properties in multiple studies. Question 2 ('Better') asks the patient the chances of their depression being completely better at the end of this study, from 1 = very poor to 7 = very good. The higher the number, the higher the expectancy that they will be better.

CES is an 8 item scale in which subjects rate their impression of the credibility of the treatment and how they estimate their expectation of improvement. The CES is the most widely used measure of expectancy and has demonstrated good psychometric properties in multiple studies. Question 2 ('Better') asks the patient the chances of their depression being completely better at the end of this study, from 1 = very poor to 7 = very good. The higher the number, the higher the expectancy that they will be better.

CES is an 8 item scale in which subjects rate their impression of the credibility of the treatment and how they estimate their expectation of improvement. The CES is the most widely used measure of expectancy and has demonstrated good psychometric properties in multiple studies. CES question 3 ('Depression') asks how the patient's depression will be at the end of the study, compared with now, from 1 = much worse to 7= much better. The higher the number, the higher the expectancy that their depression will be much better.

CES is an 8 item scale in which subjects rate their impression of the credibility of the treatment and how they estimate their expectation of improvement. The CES is the most widely used measure of expectancy and has demonstrated good psychometric properties in multiple studies. CES question 3 ('Depression') asks how the patient's depression will be at the end of the study, compared with now, from 1 = much worse to 7= much better. The higher the number, the higher the expectancy that their depression will be much better.

This 16-items assessment is used to rate the 9 criterion symptom domains of a major depressive episode: 4 items are used to rate sleep disturbance (early, middle, and late insomnia plus hypersomnia); 2 items are used to rate psychomotor disturbance (agitation and retardation); 4 items are used to rate appetite/weight disturbance (appetite increase or decrease and weight increase or decrease). Only 1 item is used to rate the remaining 6 domains (depressed mood, decreased interest, decreased energy, worthlessness/guilt, concentration/decision making, and suicidal ideation). Each item is rated 0-3. For symptom domains that require more than 1 item, the highest score of the item relevant for each domain is taken. The total score ranges from 0-27. A lower rating indicates higher expectancy of improvement and lower expectation of depressive symptomatology, and a higher rating indicates lower expectancy of improvement, higher expectation of depression.

This 16-items assessment is used to rate the 9 criterion symptom domains of a major depressive episode: 4 items are used to rate sleep disturbance (early, middle, and late insomnia plus hypersomnia); 2 items are used to rate psychomotor disturbance (agitation and retardation); 4 items are used to rate appetite/weight disturbance (appetite increase or decrease and weight increase or decrease). Only 1 item is used to rate the remaining 6 domains (depressed mood, decreased interest, decreased energy, worthlessness/guilt, concentration/decision making, and suicidal ideation). Each item is rated 0-3. For symptom domains that require more than 1 item, the highest score of the item relevant for each domain is taken. The total score ranges from 0-27. A lower rating indicates higher expectancy of improvement and lower expectation of depressive symptomatology, and a higher rating indicates lower expectancy of improvement, higher expectation of depression.

Stroop Color Word test asks patients to name the color of a word rather than reading the word. Stroop Color Word is how many colors they can name in 45 sec (higher is better, e.g., less executive dysfunction).

The Stroop is a measure of inhibition under distracting conditions that is sensitive to frontal lobe dysfunction. in Stroop Color Word test patients are to name the color of a word rather than reading the word. Stroop Color Word is how many colors they can name in 45 sec (higher is better, e.g., less executive dysfunction). Stroop Interference is this score adjusted for age and education.

Magnetic Resonance Imaging (MRI) of the Brain was acquired. We rated the severity of WMH on axial T2 FLAIR images using the Fazekas modified Coffey Rating Scale. Deep WMH are scored as 0 (absent), 1 (punctate foci), 2 (beginning confluence of foci), and 3 (large confluent areas); subcortical gray matter HIs (basal ganglia) are scored as 0 (absent), 1 (punctate), 2 (multipunctate), and 3 (diffuse); periventricular HIs are scored as 0 (absent), 1 (caps), 2 (smooth halo), and 3 (irregular and extending into the deep white matter). Our primary measure of WMH burden will be DWMH score, which has been used to establish the only empirically validated diagnostic criteria for vascular depression, where scores of 0-1 were normal, but 2-3 indicated WHM.