Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. Its Cognitive Control Factor Score is a single score that represents cognitive control function performance across multiple individual neuropsychological tests, including the Flanker task, a continuous performance test, anti-saccades test, and a set shifting test. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. We will examine its Executive Composite Score and the three factor scores (Cognitive Control, Fluency, and Working Memory). Higher scores indicate better performance.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. Its Fluency Factor Score is a single score that represents verbal fluency performance across phonemic and categorical fluency assessments. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Secondary Cognitive Outcome: The EXAMINER test battery Working Memory Factor Score is a single score that represents working memory performance across multiple individual neuropsychological tests, including the Dot counting and n-back tests. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. We will examine its Executive Composite Score and the three factor scores (Cognitive Control, Fluency, and Working Memory). Higher scores indicate better performance.

Secondary cognitive outcome, a neuropsychological test measure of attention. We will examine change in total reaction time for the CRT. Lower reaction time indicates better performance.

Secondary cognitive outcome, Selective Reminding Task as a test of immediate and delayed verbal memory. This is an 8-trial, 16-word test where the interviewer reads unrelated words to the participant who must recall them. Any missed items are then repeated before the next attempt. Scores range from 0-60, with higher scores indicating better performance. Change in the recall over 12 weeks reflect the verbal memory function, with higher scores indicating better verbal memory performance.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. Scores for positive items endorsed range from 0 to 24, with higher scores indicating more positive items being endorsed, so a reduction in negativity bias.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. Scores for negative items rejected range from 0 to 24, with higher scores indicating that more negative items are rejected, thus a reduction in negativity bias.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. A score reduction represents increased reaction time.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. A reduction in score indicates a faster reaction time.

Secondary mood outcome: Change in rumination measured by the Ruminative Response Scale total score measured at Screening visit, week 6 and week 12. This is a self-report scale with a range of 0-66, where higher scores indicate higher levels of rumination

Secondary Mood Outcomes: Change in apathy as measured by the self-report AES, a questionnaire with a range of 0-54, where higher scores indicate greater apathy. Measured at baseline, week 6, and week 12.

Secondary Mood Outcomes: Change in the severity of insomnia measures as self-report , a questionnaire with the range of 0-21 ,where higher scores indicate increase in severity. Assessed at baseline, week 6, and week 12.

Secondary mood outcome: Change in anxiety and worry measured by PSWQ, a self-report questionnaire with a range of 16-80, where higher scores indicate greater anxiety and worry. Assessed at baseline, week 6, and week 12.

Secondary outcome examining fatigue using a self-report questionnaire that ranges from 0- 56, where higher scores indicate more severe fatigue. Questionnaire administered at baseline, week 6, and week 12.

Secondary mood outcome: Change in anhedonia measured by DARS, a self-report questionnaire that ranges from 0-68, where lower scores indicate greater anhedonia. Conversely, higher scores indicate greater ability to enjoy activities. Assessed at baseline, week 6, and week 12.

Secondary Mood outcome: self-reported questionnaire to measure the severity of anxiety. Questionnaire ranges 0-24, higher scores indicates greater anxiety state. Assessed at baseline, week 6, and week 12.

Secondary Cognitive outcome:PROMIS (Patient reported outcome measurement information system) is a self-reported questionnaire to measure mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions, ranges from 0-32 , where higher scores indicate improvement. Assessed at baseline, week 6, and week 12.

Secondary Attention outcome: The Attentional Control Scale (ACS) is a self-report questionnaire that has been developed to measure individual differences in attentional control. The scale ranges from 0-80, with higher scores indicative of better attentional control, and a positive change indicated improved attentional control. Assessed at baseline, week 6, and week 12.

The ASI-3 is a self-report questionnaire assesses anxiety sensitivity, or the fear of arousal-related sensations. Specifically these derive from the belief that anxiety- or arousal-based sensations have negative consequences. This self-report scale includes 18 items with scores ranging from 0 to 72, where higher scores indicate greater anxiety sensitivity.

Scale is a cognitive screening instrument. It ranges from 0-30, with higher scores indicating better cognitive performance.

This is a depression rating scale to assess depression severity. The scale ranges from 0-60, with higher scores indicating greater depression severity.

MRI scans will be performed at baseline, week 6 and week 12. MRI will measure cognitive control network function, operationalized as a reduction in the emotional Stroop task functional MRI response in the middle and superior frontal gyri. The Stroop functional MRI response is calculated as the activation difference between incongruent and congruent conditions of the emotional Stroop task.

The primary outcome is change in activation difference across the three time points. This is examined as a categorical variable, operationalized as those subjects who exhibit a middle / superior frontal gyri z-score reduction in activation over time of 0.5 or greater, relative to baseline at either week 6 and/or week 12. The a priori threshold being tested was that 60% or more of participants would exhibit a z-score reduction of 0.5 or greater, examined separately in the left and right middle and superior frontal gyri.

Includes 29 participants randomized, 28 of whom completed all 12 weeks and 1 completed through week 6.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. Its Executive Composite Score is a single score that represents overall executive function performance across multiple individual neuropsychological tests, including the Dot counting test, the N-back test, the Flanker task, a continuous performance test, anti-saccades test, a set shifting test, and fluency tests. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This composite is generated separately from EXAMINER sub scales.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. Its Cognitive Control Factor Score is a single score that represents cognitive control function performance across multiple individual neuropsychological tests, including the Flanker task, a continuous performance test, anti-saccades test, and a set shifting test. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. We will examine its Executive Composite Score and the three factor scores (Cognitive Control, Fluency, and Working Memory). Higher scores indicate better performance.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. Its Fluency Factor Score is a single score that represents verbal fluency performance across phonemic and categorical fluency assessments. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Secondary Cognitive Outcome: The EXAMINER test battery Working Memory Factor Score is a single score that represents working memory performance across multiple individual neuropsychological tests, including the Dot counting and n-back tests. Higher scores indicate better executive function, with a range of -3.0 to 3.0. This is calculated independently of the executive composite or other factor scores.

Secondary Cognitive Outcome: This neuropsychological test battery assesses a range of executive functions. We will examine its Executive Composite Score and the three factor scores (Cognitive Control, Fluency, and Working Memory). Higher scores indicate better performance.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Secondary cognitive outcome, a neuropsychological test measure of attention. We will examine change in total reaction time for the CRT. Lower reaction time indicates better performance.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Secondary cognitive outcome, Selective Reminding Task as a test of immediate and delayed verbal memory. This is an 8-trial, 16-word test where the interviewer reads unrelated words to the participant who must recall them. Any missed items are then repeated before the next attempt. Scores range from 0-60, with higher scores indicating better performance. Change in the recall over 12 weeks reflect the verbal memory function, with higher scores indicating better verbal memory performance.

Analyses includes 28 randomized participants as 1 participant withdrew at week 6 so did not complete end of study assessments.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. Scores for positive items endorsed range from 0 to 24, with higher scores indicating more positive items being endorsed, so a reduction in negativity bias.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. Scores for negative items rejected range from 0 to 24, with higher scores indicating that more negative items are rejected, thus a reduction in negativity bias.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. A score reduction represents increased reaction time.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Participants view a series of randomized, rapidly presented positive and negative characteristics and quickly indicate whether each adjective does or does not apply to them. Positive and negative adjectives are balanced. Measures include number of adjectives endorsed or rejected, and RT for those trials. These are assessed separately for positive items endorsed and negative items rejected. Task performance assesses self-referential negativity bias and is associated with antidepressant response. Task completed at baseline, week 6, and week 12. A reduction in score indicates a faster reaction time.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary mood outcome: Change in rumination measured by the Ruminative Response Scale total score measured at Screening visit, week 6 and week 12. This is a self-report scale with a range of 0-66, where higher scores indicate higher levels of rumination

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary Mood Outcomes: Change in apathy as measured by the self-report AES, a questionnaire with a range of 0-54, where higher scores indicate greater apathy. Measured at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary Mood Outcomes: Change in the severity of insomnia measures as self-report , a questionnaire with the range of 0-21 ,where higher scores indicate increase in severity. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary mood outcome: Change in anxiety and worry measured by PSWQ, a self-report questionnaire with a range of 16-80, where higher scores indicate greater anxiety and worry. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary outcome examining fatigue using a self-report questionnaire that ranges from 0- 56, where higher scores indicate more severe fatigue. Questionnaire administered at baseline, week 6, and week 12.

29 participants analyzed, although one participant withdrew at week 6 before trial completion.

Secondary mood outcome: Change in anhedonia measured by DARS, a self-report questionnaire that ranges from 0-68, where lower scores indicate greater anhedonia. Conversely, higher scores indicate greater ability to enjoy activities. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary Mood outcome: self-reported questionnaire to measure the severity of anxiety. Questionnaire ranges 0-24, higher scores indicates greater anxiety state. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary Cognitive outcome:PROMIS (Patient reported outcome measurement information system) is a self-reported questionnaire to measure mental acuity, concentration, verbal and nonverbal memory, verbal fluency, and perceived changes in these cognitive functions, ranges from 0-32 , where higher scores indicate improvement. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

Secondary Attention outcome: The Attentional Control Scale (ACS) is a self-report questionnaire that has been developed to measure individual differences in attentional control. The scale ranges from 0-80, with higher scores indicative of better attentional control, and a positive change indicated improved attentional control. Assessed at baseline, week 6, and week 12.

Analyses includes 29 randomized participant, however 1 participant withdrew at week 6 so did not complete 12 week assessments.

The ASI-3 is a self-report questionnaire assesses anxiety sensitivity, or the fear of arousal-related sensations. Specifically these derive from the belief that anxiety- or arousal-based sensations have negative consequences. This self-report scale includes 18 items with scores ranging from 0 to 72, where higher scores indicate greater anxiety sensitivity.

Includes 29 participants randomized, 28 of whom completed all 12 weeks and 1 completed through week 6.