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Using machine learning approaches to identify imaging markers that - - PowerPoint PPT Presentation

Using machine learning approaches to identify imaging markers that predict antidepressant response Amit Etkin, MD, PhD Associate Professor Department of Psychiatry and Behavioral Sciences Stanford Neurosciences Institute Stanford University


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Using machine learning approaches to identify imaging markers that predict antidepressant response

Amit Etkin, MD, PhD

Associate Professor Department of Psychiatry and Behavioral Sciences Stanford Neurosciences Institute Stanford University Investigator, Sierra-Pacific MIRECC Palo Alto VA etkinlab.stanford.edu

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Disclosures

Equity (SAB): Akili Interactive, Mindstrong Health

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The Guardian 2/21/18 The Guardian 2/26/08

One-size-fits-all? Can the drug define the patient?

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10 20 30 40 50

4 8 12 16 20 2 4 6 8

For whom does an antidepressant work?

EMBARC (PIs: Trivedi, Weissman, McGrath, Parsey): 309 depressed patients -> sertraline vs placebo remission rate (%)

Depression severity (HAMD17)

weeks PBO SER NNT=8.4 All patients taken together:

Etkin, Fonzo, Zhang, under review

d=0.27

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Emotional conflict task

Task: identify facial expression, ignore word Emotional conflict is biologically salient

Etkin, Neuron 2006

Implicit regulation: across-trial adjustments in behavior (RT) Subjects unaware of pattern

+ ... ... +

1s 3-5s 1s 3-5s

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Emotional conflict regulation circuit

reactivity regulation dACC/ dmPFC LPFC insula amygdala vACC/ vmPFC

Etkin, Neuron 2006 Egner, Cer Cort 2008 Etkin, Am J Psych 2010 Etkin, TICS, 2011 Etkin, Am J Psych, 2011

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For whom does an antidepressant work?

Emotion conflict reactivity or regulation as a moderator?

  • Intent-to-treat framework
  • Whole-brain voxelwise FDR correction

Etkin, Fonzo, Zhang, under review

  • Conflict

regulation but not reactivity

  • Unrelated to

baseline clinical severity

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2 4 6 8 4 8 12 16 20 2 4 6 8

For whom does an antidepressant work?

Etkin, Fonzo, Zhang, under review

Remission: Symptoms:

week week below median (better regulation) above median (worse regulation)

Example result:

Depression severity (HAMD17) below median (better regulation) above median (worse regulation) remission rate (%)

NNT=3.4 d=0.76 PBO SER

10 20 30 40 50

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For whom does an antidepressant work?

Etkin, Fonzo, Zhang, under review

Machine learning to define a response phenotype:

  • Whole-brain coverage, impute HAMD17
  • Sparse Bayesian Learning, 10-fold cross-validation
  • 15
  • 5

5 15 25

  • 15

15

  • 15

15

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15 True HAMD17 change (pre-post)

SER

Predicted HAMD17 change (pre-post)

r=0.49 p<3x10-8

True HAMD17 change (pre-post) Predicted HAMD17 change (pre-post)

r=-0.06 p=0.48

SER train test SER PBO train test

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Predicting outcome with EEG

Widge, AJP, in press

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Challenges of EEG machine learning

volume conduction dimensionality reduction

  • ptimization
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A novel machine learning approach for outcome prediction

EEG

S1 S2 SN

(・)2 (・)2

∫t ∫t

C1 C2 F1 F2 Pz

Spatial Filtering Band Power Feature Extraction Linear Regression Joint Parameter Estimation to Minimize Prediction Error Treatment Outcome

Constructed as a convex optimization problem

Wu et al., in prep

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Spatial filtering

X 1 X 0.7

Spatial filter optimization is the procedure of estimating the unknown weight coefficient of each electrode spatial filter

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Individual-level outcome prediction with rsEEG

SER SER train test SER PBO train test

Wu et al., in prep

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Comparison with other models

SER SER train test

alpha power theta cordance

Wu et al., in prep

PCA ICA

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Spatial patterns contributing to the prediction

SER SER train test

+

  • +
  • scalp spatial pattern

weights cortical spatial pattern weights

latent signal with most positive regression weight latent signal with most negative regression weight

Wu et al., in prep

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Predicting across sites and equipment

Wu et al., in prep

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Do the task fMRI and rsEEG models identify a convergent treatment-responsive phenotype?

Wu et al., in prep

Correlate predictions in an independent depressed sample:

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Is the phenotype associated with differences in neural responsivity?

latent signal with most positive regression weight latent signal with most negative regression weight

Wu et al., in prep

Wu, Keller, HBM, 2018

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Is the phenotype associated with differences in neural responsivity?

latent signal with most positive regression weight latent signal with most negative regression weight

Wu et al., in prep

ቐ ቐ

aMFG pMFG M1 aMFG pMFG M1 V1

left right

✽ ✽ ✽ 0-200ms 200-400ms 400-600ms 0-200ms 200-400ms 400-600ms 0-200ms 200-400ms 400-600ms 0-200ms 200-400ms 400-600ms

𝜄 𝛽 𝛾 𝛿

aMFG pMFG M1 V1

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Study stratification using our signatures

% with 5.5 point change (SER-PBO) 10 20 30 40 50 60

Resting EEG

Overall rate

10 20 30 40 50 60

Overall rate

% with 5.5 point change (SER-PBO)

Emotional conflict fMRI

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Acknowledgements

Funding: NIMH, VA, Dana Foundation, Cohen Veterans Bioscience,

Stanford Neurosciences Institute, private donors

Collaborators Madhukar Trivedi & EMBARC Etkin lab Wei Wu Greg Fonzo Yu Zhang etkinlab.stanford.edu