Living in a dreamworld: What genetics (and epigenetics?) can tell us about lucid dreams

Have you ever become aware that you’re in a dream state while you’re dreaming?  If so, then chances are you’ve had a lucid dream.  Much like Neo plugged into a simulated Matrix, you are cognizant of your altered reality and can even manipulate your dream environment.  Lucid dreams can be quite pleasant for some people.  For others, especially those with “Reward Deficiency Syndrome” (RDS) behaviors like attention deficit hyperactivity disorder, Tourette’s syndrome, post-traumatic stress disorder (PTSD), and substance use disorder (SUD), the experience is nothing short of terrifying.  So what type of relief is there for such individuals plagued by nightmarish lucid dreaming?

You take the blue pill…

Pharmaceutical treatment seems to be one viable course of action (for Neo, it was the red pill).  Patients with RDS behaviors reported major improvements in their terrifying lucid nightmares after taking a dopamine agonist (a drug that mimics the action of dopamine), some with long-lasting effects [1].  Often dubbed the “happy hormone”, dopamine is popularly associated with feelings of well-being and pleasure.  Studies have shown a link between RDS behaviors and hypodopaminergia, a condition characterized by low dopamine function, making these agonists a logical therapy to combat RDS-associated dopaminergic dysfunction.

Evidence suggests that genetic polymorphisms associated with hypodopaminergia confer susceptibility to RDS behaviors like PTSD and SUD [2].  A gene is said to be polymorphic if there’s more than one possible DNA sequence, or variant, for that gene.  Although the majority of polymorphisms don’t disrupt normal gene expression or function, certain genetic variants can induce abnormal expression or generate a malformed protein, which could lead to disease [3].

How deep does the rabbit hole go?

The human genome is comprised of some 3 billion bases organized into approximately 20,000 genes.  Those genes are controlled by our epigenetics, so-called “on/off” switches that regulate gene expression through a variety of chemical modifications (methylation, for example) to DNA and other biomolecules.  Our epigenetic code, not to be confused with our genetic code or DNA sequence, directs normal biological processes such as cell development and specialization.  It can determine when and where genes are expressed, aptly repressing or activating expression at specific times and in specific cell types.  Aberrant changes to our epigenome can contribute to or cause numerous pathologies, including inflammatory, metabolic, infectious, cardiovascular, and neurological disorders.

Seeing as lucid dreaming is a symptom of RDS behaviors, and given the genetic basis of RDS behaviors in terms of hypodopaminergic-related polymorphisms, could there also be an epigenetic component to neuropsychiatric illness that potentiates terrifying lucid nightmares?  In a genome-wide methylation study conducted on children with a history of maltreatment, differences were observed in the DNA methylation of genes involved in neural activity and the stress response when compared with non-traumatized controls [4].  These methylation changes were found to correlate with depression, suggesting an epigenetic mechanism in the pathophysiology of stress-related psychiatric disorders.  Whether there’s also a correlation with lucid dreaming has yet to be fully explored, and further investigation is required to elucidate what role epigenetics might be playing.

Simply a matter of time

Epigenetic modifications, it turns out, are reversible.  Changes like DNA methylation can be removed just as readily as they’re added, a physiological process that’s been targeted for the benefit of patients with epigenetic dysfunctions.  In fact, DNMT inhibitors (compounds that inhibit the activity of DNA methylating enzymes) comprise one of the two classes of FDA-approved epigenetic drugs currently on the market.  Although these drugs at present are primarily geared toward treating patients with cancer, other diseases tied to abnormal epigenetics like psychiatric disorders present new therapeutic opportunities.  The potential such treatments hold in battling the terrifying lucid nightmares RDS patients suffer from remains to be seen, and only time will tell if epigenetics indeed holds the key to freeing their minds.

References

1. Blum, Kenneth et al. “Epigenetic Repair of Terrifying Lucid Dreams by Enhanced Brain Reward Functional Connectivity and Induction of Dopaminergic Homeostatic Signaling.” Current psychopharmacology vol. 10 (2021): 10.2174/2211556010666210215153513. doi:10.2174/2211556010666210215153513
2. Daskalakis, Nikolaos P et al. “Recent Genetics and Epigenetics Approaches to PTSD.” Current psychiatry reports vol. 20,5 30. 5 Apr. 2018, doi:10.1007/s11920-018-0898-7
3. Comings, D E et al. “Dopamine D2 receptor (DRD2) gene and susceptibility to posttraumatic stress disorder: a study and replication.” Biological psychiatry vol. 40,5 (1996): 368-72. doi:10.1016/0006-3223(95)00519-6
4. Weder, Natalie et al. “Child abuse, depression, and methylation in genes involved with stress, neural plasticity, and brain circuitry.” Journal of the American Academy of Child and Adolescent Psychiatry vol. 53,4 (2014): 417-24.e5. doi:10.1016/j.jaac.2013.12.025