Steven P. Ellis is Associate Professor of Clinical Neurobiology (in Psychiatry) at Columbia University. He is the Co-Leader of the Database and Statistical Core 4 in the Conte Center for Suicide Prevention: Neurobiological and Developmental Antecedents of Suicidal Behavior Related Neurobiology.

Dr. Ellis graduated cum laude with Honors with Exceptional Distinction in Mathematics, and with a masters degree in mathematics awarded simultaneously with the bachelor’s degree after four years at Yale. He also was awarded the DeForest Mathematical Prize at Yale. He was awarded an NSF Graduate Fellowship in mathematics. Dr. Ellis was PI on the grant “Statistical Analysis of Neurochemical Maps” (R21 MH60995, NIMH).

Research Focus

Dr. Ellis’s interests include multivariate analysis and statistical computing.

Select Publications

1. Ellis, S.P. Dimension of the singular sets of plane-fitters, Annals of Statistics, 23, 490-501, 1995.

2. Ellis, S.P. Instability of least squares, least absolute deviation, and least median of squares linear regression (with discussion). Statistical Science 13(4), 337-350, 1998.

3. Ellis SP, Underwood MD, Arango V, Mann JJ. Mixed models and multiple comparisons in analysis of human neurochemical maps. Psychiatry Res. 2000 Aug 28; 99(2):111-9. PMID:10963986

4. Ellis, S.P. “Fitting a line to three or four points on a plane” SIAM Review, 44, 616-628, 2002.

5. Oquendo MA, Barrera A, Ellis SP, Li S, Burke AK, Grunebaum M, Endicott J, Mann JJ. Instability of symptoms in recurrent major depression: a prospective study. Am J Psychiatry. 2004 Feb; 161(2):255-61. PMID: 14754774

6. Grunebaum MF, Ellis SP, Li S, Oquendo MA, Mann JJ. Antidepressants and suicide risk in the United States, 1985-1999. J Clin Psychiatry. 2004 Nov; 65(11):1456-62. PMID:15554756

7. Nakagawa A, Grunebaum MF, Ellis SP, Oquendo MA, Kashima H, Gibbons RD, Mann JJ. Association of suicide and antidepressant prescription rates in Japan, 1999-2003. J Clin Psychiatry. 2007 Jun;68(6):908- 16.PMID:17592916

8. Mann JJ, Ellis SP, Waternaux CM, Liu X, Oquendo MA, Malone KM, Brodsky BS, Haas GL, Currier D. Classification trees distinguish suicide attempters in major psychiatric disorders: a model of clinical decision making. J Clin Psychiatry. 2008 Jan; 69(1):23-31. PMID:18312034

9. Bach-Mizrachi, H.; Underwood, Tin, A.; Ellis, S.P.; Mann, J.J.; Arango, V. “Elevated expression of Tryptophan Hydroxylase 2 mRNA at the neuronal level in the dorsal and median raphe nuclei of depressed suicides” Molecular Psychiatry 2008 January 8;13(5):507-13. [PMID: 18180753]

10. Zalsman G, Mann MJ, Huang YY, Oquendo MA, Brent DA, Burke AK, Ellis SP, Mann JJ. Wolframin gene H611R polymorphism: no direct association with suicidal behavior but possible link to mood disorders. Prog Neuropsychopharmacol Biol Psychiatry. 2009 Jun 15; 33(4):707-10. Epub 2009 Mar 26. PMID: 19328217

11. Ellis, S.P., Stewart, JW. “Temporal Dependence and Bias in Meta-Analysis” Communications in Statistics – Theory and Methods. Volume 38, Issue 15, 2009, Pages 2453 – 2462

12. Ellis, S.P. “When a constant classifier is as good as any linear classifier” Communications in Statistics – Theory and Methods, 2011, Volume 40, Issue 21, 3800-3811

13. Sublette ME, Ellis SP, Geant AL, Mann JJ, “Meta-analysis: effects of eicosapentaenoic acid in clinical trials in depression” The Journal of Clinical Psychiatry. 2011, Dec;72(12):1577-84. Epub 2011 Sep 6. [PMID: 21939614]

14. Ellis, S.P. “An algorithm for unconstrained quadratically penalized convex optimization”, Communications in Statistics – Simulation and Computation, July 2011, Volume 40, Issue 7, pages 1006-1029.

15. S.P. Ellis, A. Klein (2014) “Describing high-order statistical dependence using `concurrence topology’, with application to functional MRI brain data,” Homology, Homotopy, and Applications, 16, 245–264.