Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2007.3307.3311Moazami GodarziAli KianpoorFatemeh Zarra NezhadMaryam 122007721This study aims at investigating the relationship between the birth order and schizophrenia. The research is conducted based on case studies carried out in Roozbeh Hospital of Tehran. Among the patients bedridden in this hospital during 2003-2004, 200 schizophrenics were selected through random sampling. This research was conducted in a field work fashion using information recording file which was based on the available documents. Results suggested that the distribution of schizophrenia among the children of a family differs in terms of their birth order. The risk of schizophrenia is relatively greater in case of either the first male or the last female children. Overall, it can be claimed that there is a significant relationship between birth order and schizophrenia. The results also showed that among the studied sample, none belonged to single-child families. Besides, the number of first-and last-child schizophrenia was equally the highest among the subjects of the research.]]>Ahmad, J.,1994Alfred, A.,1982APA.,20004th Edn.,Barry, H.,19673439444Behrokh, F.,19881988Bender, K., N. Azeem and J. Morrice,200044113120Bohmer, P. and S. Sitton,199343375380Book, J.A.,195341100Claxton, R.P.,199444475487Crow, T.J.,19802806668Elliott, B.A.,199235443452Ernst, C. and J. Angst,1983Farina, A., H. Barry and N. Garmezy,19639224228Freese, J., B. Powell and L.C. Steelman,199964207231Gaughran, F., R. Blizard, R. Mohan, S. Zammit and M. Owen,200750205210Goodman, N.,195711203213Granville-Grossman, K.L.,196611211191126Gregory, I.,195995496Hare, E.H. and J.S. Price,1970116409420Haukka, K.J., J. Suvisaari and J. Lonnqv,200444141Kaplan, H. and B. Sadock,20039th Edn.,Kemppainen, L., J. Veijola, J. Jokelainen, A.L. Hartikainen and M.R. Jarvelin et al.,2001104148152McDonald, C., E. O'Callaghan, F. Keogh, P.C. Sham, A. Kinsella, M. Morris and D. Walsh,200147275280Schooler, C.,196469574579Sham, P.S., C.J. MacClean and K.S. Kendler,1993163627633Stompe, T., G. Ortwein-Swoboda, A. Friedmann and H.R. Chaudhry,200047357380Tsuang, M.T.,196611211311141Wahl, C.W.,1956113201210