4World Health Organization.Mental Disordrs:Glossary and guide to their classification in accordance with the Ninth Revision of the International Classification of Disease.(ICD-9).Geneva:WHO,1978.
7Andressen NC,Black D W.Introductiry Textbook of Psychiatry.Washington DC:Am psychiat Press,1991:207.
8Akiskal H S.Towards a definition of dysthymia:boundaries with personality and mood disorders,in Dysthymic Disorder.Burton S W,A kiskal H S eds.Dythymic Disorder.London:Royal College of Psychiatrists; 1990:1-12.
9Leonarl LG.Depression and anxiety disorders during multiple pregnancy and parenthood.Joumal of Obstet-rics and Gynecology Neonatal Nursing,1998,27(3):329-337.