Genetic Insights into Why Depression Affects Women More Than Men

       In a recent study done by Dr. Jodi Thomas at the School of Biomedical Sciences at The University of Queensland, it has been found that major depressive disorder (MDD) impacts almost twice as many women as it does men. Researchers findings in the study with over 200,000 men and women with MDD start to unpack the underlying causes of MDD in both sexes. They categorized genetic effects into three separate groups: shared effects present in both sexes, sex-dependent effects that differ in magnitude or direction, and sex-specific effects present in only one sex. Their analysis revealed that women carry about 13,200 genetic variants linked to MDD while men have only 7,100, suggesting that women might bear a higher genetic burden (including 6,100 variants potentially unique to females). Additionally, three genomic regions were identified as major only in women, supporting the presence of sex-specific genetic influences.

The study also focused on genetic correlations between MDD and metabolic traits like body mass index (BMI) and metabolic syndrome. These correlations were stronger in women, consistent with clinical observations that women with MDD more often experience metabolic symptoms. With this, researchers recorded limitations in statistical power, meaning that not all causal genetic regions could be definitively identified. In addition, genetic correlations between men and women with MDD were slightly lower than expected, underscoring possible differences in cohort characteristics. This suggests that twin studies and GWASs may capture distinct aspects of genetic risk.

    Ultimately, the study highlighted a noteworthy variant on the X chromosome in men, mapping to the IL1RAPL1 gene, which is involved in memory and has been associated with several other traits but not previously with MDD. While the role of this gene in male depression is still unclear, it provides a promising opportunity for further research. Overall, the study harps on the importance of sex-stratified analyses to comprehend the biological function of MDD and points to the need for more data collection and further investigation into molecular mechanisms that mediate sex-dependent and sex-specific genetic impacts.

Sources:

https://www.nature.com/articles/d41586-025-03374-0

https://www.nature.com/articles/s41467-025-63236-1

https://www.mayoclinic.org/diseases-conditions/depression/symptoms-causes/syc-20356007

Genetics to be blame for nearly all autism cases in twin study

According to a recent article, a British study has revealed that Autism Spectrum Disorder (ASD) is caused by genetics in about 98% of the cases. This discovery has undermined many modern theories blaming environmental factors such as air pollution. In this study, scientists collected evidence from a population based sample and found that genetic factors outweigh environmental influences. The results were published online this week which showed that over 6,000 twin born in England between 1994 and 1996 had a variety of autism related traits. The main finding from the study was that the heritability of ASD was high. Identical twins were shown to have a much higher heritability estimates than fraternal twins. The results of the study confirmed that genetic factors lead a variety of autistic skills and behavior across the general population.

I think this is an important discovery. It will help us find the cause of this disorder. After reading this article, I learned that 1 in 68 children were diagnosed with Autism disorder in 2010. This number was increased from 1 in 150 cases in 2000.

Twin Smokers Study Suggests Greater Genetic Influence

A study by the University of Colarado Boulder of the smoking patterns of over 596 twins, 363 of them identical and 233 of them fraternal, suggests that today's smokers may have a greater genetic influence than those in the past. The study involved a questionnaire focusing on smoking habits from 1960-1980, a period of changing views on smoking. One of the study's co-authors, Professor Fred Pampel, stated that, ""In the past, when smoking rates were higher, people smoked for a variety of reasons. Today the composition of the smoking population has changed. Smokers are more likely to be hard-core users who are most strongly influenced by genetic factors." Between identical twins, 65% of both twins quit within a two year time period if the other twin quit. Between fraternal twins, this dropped to 55%, suggesting a genetic component. So, fraternal twins sharing the same twins showed greater similiarities in their smoking habits and level of addiction. Also, if one twin continued to smoke it was more likely that the other twin would not quit smoking. Although the researchers concede that a specific genetic marker is hard to identify, they say that the study shows many genetically similiarities. Smoking-related diseases lead to approximately 443,000 deaths a year in the United States. Anti-smoking campaigns had previously drastically cut the smoking population, the number has flatlined over the past years, suggesting a genetic influence. The study suggests that this could change anti-smoking campaigns to treating it as more of an addiction than a choice, due to the growing genetic component of smoking. Maybe now nioctine addiction will be viewed similiarly to alocholism or drug addiction and taken more seriously by the public.