Smoking & ADHD - Kate Langley

Question 1

Aim

Answer 1

Does Smoking cause ADHD in foetuses?

Question 2

Procedure (1st study)

Answer 2

• Observational
• Looking at 800 Mothers who smoke & if their kids have ADHD symptoms

Question 3

Second Study

Answer 3

• Hyp: Sig association when mums smoke but not dads, comparing maternal/paternal risk
• Paternal should not matter as he’s not pregnant
• Large longitudinal study (large N)
• Split into mothers & fathers
• Split into smokers/non-smokers during pregnancy
• Looked at ADHD symptoms in kids
• Regression analysis (controls confounders)

Results:
- No diff regardless of which parent smoked, risk of ADHD was no different
- Also shows passive smoking is no risk so it cannot be causal

Question 4

Procedure (Additional Designs)

Answer 4

• Comparing ADHD in siblings where mum smoked in one pregnancy but not the other: risk was same for sibs
• Kids born through IVF: where mum is unrelated to kid. ADHD present if bio mum carries

Question 5

Conclusion

Answer 5

• Smoking is not causal to ADHD development

Question 6

Limitations:

Answer 6

1st study:
- No manipulation if observational
- Correlation is not causation

Testing causality:
- Normal designs can’t identify causality or confounders
- Natural experiments: lack of control = causation hard to find, also have to rely on circumstances

Second Study:
- Questionnaires sent: sample bias
- Interviews: prone to bias
- Tests on children: ethics questioned as well as reliability (liar)
- Memory: detoriates
- Measuring symptoms of ADHD how? Valid?

Question 7

Positives

Answer 7

• Natural experiment = higher EV, remove something in the pathway, experience things they would see in the Lab, more Mundane Realism
• School reports: non-biased view
• Interviews: rich detailed data
• Longitudinal study
• Ideas of different/flexible methodology