Heston

Question 1

What is the aim ?

Answer 1

• To see how many adopted children of biological mothers with sz would go on to develop sz themselves
• If significant number did so, constitutes to powerful evidence for role of genes on sz

Question 2

What is the sample ?

Answer 2

• 47 experimental & 50 controls
• Experimental = all born between 1915-1945 to sz mothers confined to an Oregon State psychiatric hospital
• Control = mothers believed to be mentally healthy

Question 3

What was the procedure ?

Answer 3

• Asked to do personal standardised, structured interview
• General medical & environmental questionnaire exploring psychosocial dimensions
• Adults interviewed to see whether any had gone to develop sz themselves
• Information gathered was evaluated blindly by 2 independent psychiatrists
• Final evaluation by 3rd researcher

Question 4

What were the results ?

Answer 4

• 5 hospitalised with sz
• 10% of adopted children with sz mothers developed sz
• None of controls developed sz = adoption not factor in sz

Question 5

What was concluded ?

Answer 5

• Provides powerful evidence for role of genes in sz
• No evidence emerged for role of environmental factors in development of sz

Question 6

What was previously established about sz ?

Answer 6

• Risk of developing sz if one parent had it was 10%
• Incidence in population at large is 1%