Do you have Brain Fog? Why it may be more than you think.

In my integrative psychiatry and neurologic health practice, I frequently encounter patients who describe feeling "foggy" or "not quite themselves," often attributing these sensations to "brain fog." However, I have found that for many, these experiences reflect something completely different: Dissociation! More specifically, depersonalization and derealization (DP/DR), two forms of dissociation that are distinct from the cognitive cloudiness of brain fog. Mislabeling DP/DR as brain fog can obscure underlying conditions like anxiety, post-traumatic stress disorder (PTSD), or chronic stress, delaying effective treatment. This post explores DP/DR, their neurophysiological underpinnings, and their connections to these conditions, emphasizing the importance of accurate diagnosis.

What Are Depersonalization and Derealization?

Depersonalization involves a sense of detachment from oneself, where individuals feel disconnected from their body, emotions, or thoughts. Patients might describe feeling like they’re observing themselves from outside or living on autopilot (American Psychiatric Association, 2013). Derealization, conversely, manifests as a sense that the external world is unreal, dreamlike, or distant, as if life is a movie or objects lack vibrancy (Simeon & Abugel, 2006). Both are dissociative phenomena, often co-occurring, and can be profoundly distressing, yet they’re frequently mistaken for brain fog—a term typically associated with cognitive difficulties like poor concentration or memory (Ocon, 2013).

Unlike brain fog, which is often linked to fatigue or medical conditions like long COVID (Ceban et al., 2022), DP/DR involve a perceptual and emotional disconnect. For instance, a patient with depersonalization might say, “I feel like a robot,” while someone with derealization might note, “The world looks flat, like I’m not really here.” These experiences can be transient or persistent, particularly when tied to mental health conditions.

Connections to Anxiety, PTSD, and Chronic Stress

Depersonalization and derealization can occur alongside anxiety and PTSD. Dissociation may be experienced during periods of intense stress, but symptoms and contributing factors differ between people (Spiegel et al., 2011). An individual assessment is important; these experiences do not establish a particular diagnosis on their own.

The DSM-5 recognizes a dissociative subtype of PTSD in which depersonalization or derealization is prominent. These symptoms occur in some people with PTSD, rather than in every person with the condition (American Psychiatric Association, 2013; Lanius et al., 2010).

Stress may be relevant to a person’s symptoms, but it should not be assumed to explain them. A clinician can assess the experiences themselves, their timing, and any co-occurring mental or physical health concerns.

Neurophysiology of DP/DR

One proposed model links depersonalization to increased prefrontal activity that inhibits emotional processing, including amygdala activity; this is a hypothesis, not a settled mechanism (Sierra & Berrios, 1998). Imaging research has found differing brain correlates for dissociation, anxiety, depression, and somatization, but mechanisms remain incompletely understood (Lemche et al., 2016).

These research findings do not provide a stand-alone diagnostic brain scan. Research on fatigue and cognitive impairment after COVID-19 also does not establish that an individual’s brain fog is dissociation (Ceban et al., 2022). Symptoms need to be assessed in their own clinical context.

Why Misdiagnosis Matters

Brain fog and dissociation describe different experiences and can have different contributing factors. An open study of 21 patients reported improvement in depersonalization with cognitive-behavioral therapy, but larger controlled trials are needed to establish its effectiveness (Hunter et al., 2005). Treatment for co-occurring conditions should be tailored to the individual.

Misdiagnosis also risks overlooking serious conditions. Persistent DP/DR may signal depersonalization-derealization disorder, a standalone condition requiring specialized care (Simeon & Abugel, 2006). In my practice, I’ve seen patients with long COVID attribute dissociation to cognitive impairment, delaying treatment for underlying anxiety or stress-related disorders.

Moving Forward

If you feel detached from yourself or the world feels unreal, don’t assume it’s just brain fog. These could be signs of depersonalization or derealization, especially if you’re navigating anxiety, PTSD, chronic stress, or even long COVID. Consult a mental health professional to explore these symptoms—they’re more common than you might think, and naming them is the first step toward relief.

About the Author

Dr. David George, PMHNP-BC, FNP-BC, DC, CBIS, is the founder of Neuregen in Scottsdale, Arizona. The clinic provides integrative psychiatric and neurological rehabilitation care. Information about ketamine therapy and stellate ganglion block is provided on their separate treatment pages. Their inclusion here does not establish effectiveness for depersonalization or derealization; suitability, evidence, risks, and the treating clinician’s role require individual assessment.

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Publishing.

Ceban, F., Ling, S., Lui, L. M. W., Lee, Y., Gill, H., Teopiz, K. M., ... & McIntyre, R. S. (2022). Fatigue and cognitive impairment in post-COVID-19 syndrome: A systematic review and meta-analysis. Brain, Behavior, and Immunity, 101, 93–135. https://doi.org/10.1016/j.bbi.2021.12.020

Hunter, E. C. M., Phillips, M. L., Chalder, T., Sierra, M., & David, A. S. (2003). Depersonalisation disorder: A cognitive-behavioural conceptualisation. Behaviour Research and Therapy, 41(12), 1451-1467. https://doi.org/10.1016/S0005-7967(03)00066-4

Lanius, R. A., Vermetten, E., Loewenstein, R. J., Brand, B., Schmahl, C., Bremner, J. D., & Spiegel, D. (2010). Emotion modulation in PTSD: Clinical and neurobiological evidence for a dissociative subtype. American Journal of Psychiatry, 167(6), 640-647. https://doi.org/10.1176/appi.ajp.2009.09081168

Lemche, E., Surguladze, S. A., Brammer, M. J., Phillips, M. L., Sierra, M., David, A. S., ... & Giampietro, V. (2016). Dissociable brain correlates for depression, anxiety, dissociation, and somatisation in depersonalization-derealization disorder. CNS Spectrums, 21(1), 35-42. https://doi.org/10.1017/S1092852913000588

Ocon, A. J. (2013). Caught in the thickness of brain fog: Exploring the cognitive symptoms of chronic fatigue syndrome. Frontiers in Physiology, 4, 63. https://doi.org/10.3389/fphys.2013.00063

Sierra, M., & Berrios, G. E. (1998). Depersonalization: Neurobiological perspectives. Biological Psychiatry, 44(9), 898-908. https://doi.org/10.1016/S0006-3223(98)00015-8

Simeon, D., & Abugel, J. (2006). Feeling unreal: Depersonalization disorder and the loss of the self. Oxford University Press.

Hunter, E. C. M., Baker, D., Phillips, M. L., Sierra, M., & David, A. S. (2005). Cognitive-behaviour therapy for depersonalisation disorder: An open study. Behaviour Research and Therapy, 43(9), 1121–1130. https://doi.org/10.1016/j.brat.2004.08.003

Spiegel, D., Loewenstein, R. J., Lewis-Fernández, R., Sar, V., Simeon, D., Vermetten, E., ... & Dell, P. F. (2011). Dissociative disorders in DSM-5. Depression and Anxiety, 28(12), E17-E45. https://doi.org/10.1002/da.20923

van der Kolk, B. A. (2014). The body keeps the score: Brain, mind, and body in the healing of trauma. Viking.