Genetic Breakthroughs in Bipolar Disorder Blog #2

 

Angelina Tadros

Genetics Blog #2

Dr. Barbato

November 20, 2025

Genetic Breakthroughs in Bipolar Disorder

Bipolar disorder (BD) is a highly heritable psychiatric condition. Its genetic basis has been difficult to map because it involves many small genetic effects rather than a singular “bipolar gene”. This large multi-ancestral study broadens our understanding by identifying 298 genetic loci linked to BD, making it one of the strongest genetic analyses done so far. The researchers compared clinically diagnosed cases with a large set of self reported data (from 23AndMe and others), finding that the self reported samples often more closely resemble BD type II, while clinically established samples matched better with BD type I and schizophrenia related genetic patterns. This shows that bipolar disorder varies across different groups of patients (clinically diagnosed and self reported), and that the type of sample researchers use can influence the kind of genetic patterns they see.

This study further revealed that many of the identified genetic variants influence pathways involved in synaptic function( how neurons communicate with each other at the synapses), dopamine and calcium signaling, and specific neuron types in the prefrontal cortex and hippocampus- areas heavily involved in mood regulation. Genetic risk scores are able to now give some sort of an idea of who might inherit/develop bipolar disorder, especially when using high quality clinical data, although they are not yet reliable enough for medical decisions. Still, the study identified over 100 genes that may contribute to the disorder, showing links between bipolar disorder, schizophrenia, and other mental health conditions.

Figure 1-shows the correlation, and standard error, between BD and other disorders

This research is important for individuals living with bipolar disorder because it ensures that BD is a biological, brain-based condition, not an issue of personal weakness. By exposing how complex the genetics of bipolar disorder truly are, this study helps scientists move a step in the right direction toward more accurate/precise diagnoses and possibly better treatments at some point in the future. While the results are not yet entrusted to predict who will get BD, it offers an opportunity to better understand and grow in how we think and address similar situations. The study ultimately brings us closer to understanding its biology and offers hope for improved therapies in the future.

Article link +picture link 

https://www.nature.com/articles/s41586-024-08468-9

Similar article https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(09)60072-6/abstract

Linking Dog Behavior and Genetics

 

    In a study done among 101 dog breeds, it was found that certain behaviors were related between genetically similar breeds. It is common knowledge that different breeds of dogs differ in their behavior, but the genetics behind this have been of interest in recent years. In performing this study, data came from databases as well as surveys from dog owners, asking dog owners about their purebred dog's behavior. They collected data from over 14,000 dogs, and gave each dog a score on fourteen different behaviors. Geneticists analyzed these behavior scores, looking for genetic similarities between dogs who had similar behavior scores. They discovered that for behaviors such as aggression, trainability, and chasing, genes contributed between 60% to 70% of behavioral variation among breeds. For example, border collies and poodles had higher trainability scores while chihuahuas had higher aggression scores. The strong correlation between certain behaviors and genetics shows that the specific behaviors that genetics play a role in have been selected over time by humans. Humans have bred for specific traits, which is increasing the correlation. 

    The scientists also looked into specific genetic variants that might also contribute to behavioral differences. 131 out of thousands of variants stood out, but after much research, it was decided that no single gene was very closely related to any behavior. This just means that differences in behavior between breeds is affected by multiple genes, all interacting with each other. Although genes do play a role in the predisposition of behavior in dogs, environment still plays a role in dog behavior. That being said, I think that environment may play a larger role in dog behavior than genes. If a dog is raised in an abusive home, most of the time, they will be more aggressive and hostile, solely because of the way they have been treated. On the contrary, if you raise a dog in a positive, healthy environment, they will most likely be friendlier. A trait that I think could be affected more by genes than environment however, would be trainability. It would be interesting to see more research done on that trait in different dog breeds. 

https://www.sciencenews.org/article/dog-breed-behavior-genetics

https://penntoday.upenn.edu/news/genes-play-role-dog-breed-differences-behavior