Cover Letter 5

Tesfa Dejenie Habtewold (BSc, Msc, CRN)
Department of Psychiatry and Epidemiology
University of Groningen
Hanzeplein 1
Groningen, 9713 GZ
[email protected]
+316 3015 6447

06 November 2019

Henrik Larsson and Sara Tiste
Department of Medical Epidemiology and Biostatistics (MEB)
Solna, Sweden
Tel: 08 524 870 02/08-524 822 84

Dear Recruiting Team,

I am writing to apply for the postdoctoral position in the epidemiologic studies of neurodevelopmental disorders in the department of Medical Epidemiology and Biostatistics (MEB) at Karolinska Institutet as advertised on the institute webpage (www.ki.se). I am a Ph.D. student at University of Groningen in University Center for Psychiatry and department of Epidemiology, where healthy aging is the main research focus, working under the supervision of professor Richard Bruggeman (Neuropsychiatrist), professor Marike Boezen (genetic Epidemiologist) and Dr. Behrooz Z. Alizadeh (genetic Epidemiologist). I expect to submit my thesis in the coming three to six months and receive my Ph.D. degree in September 2020. My experiences on advanced epidemiological analytical methods (i.e. multilevel analysis, group-based trajectory modeling, machine learning) and big (non-)genetic data analysis using SAS, R, STATA, Python, PLINK and SPSS along with my epidemiology training background at the University of Groningen, make me a strong candidate for the postdoctoral position.

The aim of my Ph.D. project is to dissect the clinical and statistical heterogeneity of schizophrenia spectrum disorders using cardiometabolic and neuropsychiatric outcomes in patients, their unaffected siblings and healthy controls using family-based cohort data in Dutch population. In a cross-sectional study (Study I) involving 1,129 patients with schizophrenia spectrum disorder, I found a significant association between glycated hemoglobin level and use of antipsychotic drugs, high body mass index, blood pressure and cholesterol, age of diseases onset, and polygenic risk score of schizophrenia (PRS_SCZ) and type 2 diabetes (PRS_T2D). In a systematic review (Study II) of 50 cluster- and trajectory-based studies conducted in 30 countries,  I found two to five subtypes of neurocognitive deficits, and positive and negative symptoms/schizotypy with variable long-term trajectories in patients with schizophrenia spectrum disorders, their siblings and healthy people. Numerous environmental factors, including cognitive activity, depressive and somatic symptoms, lifestyle activity, general psychopathology and severity of diseases symptoms  predicted subtypes and longitudinal trajectories. In the 10 years longitudinal cohort study (Study III to V) involving 1,136 patients with schizophrenia spectrum disorders, 1,045 unaffected siblings and 583 healthy controls, I applied a combination of group-based trajectory modelling, polygenic risk score analysis and multilevel analysis to examine heterogeneity and predictors. I discovered cognitive impairment, and positive and negative symptoms are more heterogeneous than currently recognized and associated with poor cardiometabolic health, severity of symptoms, cognitive activity, and genetic susceptibility (i.e. PRS_SCZ).

I see this project as the starting point for my long-term research goal of investigating neuropsychiatric disorders, and expanding knowledge and skills in register-based data analysis. Elucidating the benefits and risks associated with ADHD treatment interventions across multiple medical and functional outcomes as well as their healthcare utilization and costs associated with them will be the top priority during the my postdoctoral work. I received broad training in Clinical and Psychosocial Epidemiology during my master’s degree study in Graduate School of Medical Science at the University of Groningen, The Netherlands. At the same time, I have actively taken (summer)courses and seminar classes in designing epidemiological studies, applied longitudinal data analysis, mixed models for clustered data, group-based trajectory modeling, psychiatric epidemiology and machine learning.

I am excited about the opportunity to work with researchers, doctoral students, biostatisticians, data collectors and database administrators at Karolinska Institutet, and facilitate the collaboration of researchers at Karolinska Institutet, Indiana University, the University of Chicago, and the Centers for Disease Control and Prevention in Atlanta. Enclosed you will find my CV. Please let me know if I can provide additional information or materials required for my application. Thank you in advance for your time and consideration of my application. I look forward to hearing from you.

Yours sincerely,

Tesfa D. Habtewold