A recent psychiatric study indicates that Major Depressive Disorder (MDD) has a significant hereditary component.
Sarah's mother suffered from severe MDD. Sarah is considering undergoing genetic screening to see if she will develop MDD in the future.
Explain why Sarah’s genotype will not reveal for certain whether she will suffer from Major Depressive Disorder.
48 exam-style questions on AQA A Level Psychology Biological approach. Each one has a worked solution and a mark scheme showing where the marks go.