Ruh Sağlığı Alanında Genetik ve Çevre: İkiz Araştırmaları

Bu çalışmanın amacı, psikiyatri ve psikoloji alanları için önemli bir bilgi kaynağı olan ikiz araştırmalarının betimlenmesidir. İkiz araştırmaları, çevre ve kalıtım arasındaki sınırları belirlemeye odaklanmaktadır. Özellikle bu konuda yürütülen güncel araştırmalarda genetik ve çevresel faktörlerin önemine yapılan vurgu dikkate değerdir ve bu derleme çalışmasının da ana vurgularından birini oluşturmaktadır. Araştırmacılar için, ikiz araştırmalarının planlanmasında ve tasarlanmasında öne çıkan temel bileşenler, “çalışma deseni olarak ikiz araştırmalarının tercih edilme nedeni”, “ikiz araştırmalarında kullanılan temel varsayımlar”, “ikiz araştırmalarının sınırlılıkları” ve “yöntem olarak tercih edilen güncel ikiz desenleri”dir. Bu sebeple öncelikle bu temel bileşenlerden bahsedilecektir. Alanyazında öncü sayılan araştırmacılar tarafından tanımlanan ve ikiz araştırmalarında sıklıkla kullanılan on dört ikiz araştırması deseni ve bu araştırma desenlerinin kullanıldığı araştırma bulgularına da yer verilmiştir. Bu araştırmaların bazılarının alanda sıklıkla tercih edildiği, bazılarının ise örneklem zorluğu nedeniyle sınırlı sayıda yürütüldüğü görülmektedir. Ancak tüm araştırma desenlerinde, genetik ve çevrenin karşılıklı etkileşimlerine vurgu yapan araştırmaların, araştırmacılar için güncelliğini ve önemini koruduğu görülmektedir. Son olarak, ikiz araştırmalarının sınırlılıkları hakkında prospektif araştırmalara yönelik önerilerde bulunulmuştur.

Genetic and Environment in Mental Health: Twin Studies

The purpose of the current study is to portray the twin research characteristics as a valuable information source to the fields of psychiatry and psychology. Twin research focuses on determining the boundaries between environment and heredity. The emphasis on the importance of genetic and environmental factors in current twin researches is remarkable and constitutes one of the main highlights of this review. For researchers, twin studies involve mainly prominent components in the planning and designing of twin research. These components are ‘the reasons for twin research preference, ‘basic underlying assumptions,’ ‘limitations,’ and ‘current approaches to be preferred’ in twin research. For this reason, these main components will be discussed. Fourteen twin research designs are defined, which were prescribed by the proponents of twin research, and the findings are also indicated. It is seen that some of these researches are frequently preferred in the field, but some of them are carried out in a limited number due to sampling difficulties. However, when all research designs are examined concerning the literature review, it can be concluded that specifying the interactions of genetics and environment in twin research still maintains its importance researchers about the limitations of twin research.

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