Genetic Factors in Mental Health

Study Notes

Not all individuals with a genetic relationship to someone with a mental health disorder will experience the same issues.
Genetic factors have been associated with various conditions such as cancer, diabetes, asthma, and depression.
Unipolar depression may be hereditary, but specific genes involved are still unclear.
Hyde et al. (2016) identified 17 gene variations linked to increased risk of developing depression.

Identical twins (monozygotic) share 100% of their genes, while non-identical twins (dizygotic) share about 50%.
Research by McGuffin (1996) showed a 46% chance of both identical twins being depressed if one is diagnosed, in contrast to a 20% chance for non-identical twins.
Findings suggest genetic factors play a significant role in depression risk, although environmental factors may also be necessary to trigger its onset.

A genetic predisposition to depression can exist without manifesting unless triggered by environmental stressors (e.g., job loss, bullying).
This indicates that while genetics set a potential risk, personal experiences significantly influence whether depression develops.

Caspi (2003) discovered that variations in the serotonin transporter gene make individuals more reactive to stress, frequently leading to depression.
The genetic explanation of depression supports understanding mental health as an illness that can be influenced by inherited traits.

Addiction can also be influenced by genetic factors, with studies showing familial links.
Identical twins display a higher likelihood of smoking if one of them smokes (Carmelli et al., 1992).
Goodwin et al. (1973) noted that adopted children with biological parents having alcohol addiction are more prone to develop similar issues.

Cadoret's study identified that adopted children with a biological link to those with alcohol problems are more likely to have their own addiction issues.
It suggests that genetics contribute to addiction while also highlighting the influence of the environment.

Strengths
- Reduced stigma surrounding mental health as genetic factors imply individuals cannot be blamed for conditions like depression.
- Recognition of genetic predisposition encourages people to seek help.
Weaknesses
- Genetic explanations can be seen as deterministic, suggesting lack of agency in managing mental health.
- Reductionist approach fails to account for other significant factors (e.g., life events and environment) that affect the development of depression and addiction.

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