You thought you’d moved on. The traumatic event happened years ago—maybe five, ten, or even twenty years back. You built a life, pursued your career, maybe started a family. But lately, something’s shifted. You’re having nightmares about the incident. Loud noises send you into panic mode. You’re avoiding places that remind you of what happened, even though you haven’t thought about it in years.
If this sounds familiar, you’re not alone. Research shows that 20-30% of people with PTSD don’t develop symptoms until at least six months after their trauma, with this delayed onset being even more common among military personnel and veterans (Bonde et al., 2022). Here in San Diego, where we have one of the largest military populations in the country, understanding delayed-onset PTSD isn’t just academic—it’s personal for thousands of families in our community.
What Delayed-Onset PTSD Actually Means
Think back to the 1960s, when the medical community believed PTSD symptoms always appeared within weeks of a traumatic event. Fast forward to today, and we know better. Delayed-onset PTSD refers to cases where the full diagnostic criteria for PTSD aren’t met until more than six months after the traumatic event occurred (Andrews et al., 2007).
Here’s what makes this tricky: delayed-onset PTSD rarely appears completely “out of the blue.” Most people who develop delayed symptoms actually had some level of subthreshold symptoms—smaller warning signs that didn’t quite add up to full PTSD—bridging the gap between their trauma and when things intensified (Bonde et al., 2022). You might have had occasional bad dreams, felt a bit jumpy around certain triggers, or noticed yourself avoiding particular situations. These weren’t dramatic enough to seek help, but they were there, quietly simmering beneath the surface of your daily life.
Why Symptoms Surface Years Later
The brain is remarkably complex, especially when it comes to processing trauma. Several neurobiological mechanisms can explain why PTSD symptoms might emerge long after the traumatic event itself.
The Sensitization Process
Your brain has a kind of memory for stress responses. Through a process called sensitization, repeated exposure to stressors—even ones unrelated to your original trauma—can progressively lower the threshold for triggering PTSD symptoms (Shalev et al., 2022). Think of it like this: your nervous system becomes increasingly sensitive over time, until eventually something tips the scale and full symptoms emerge.
This explains why many people develop delayed PTSD following major life stressors that have nothing to do with their original trauma. A divorce, job loss, health crisis, or even positive changes like becoming a parent can activate dormant trauma responses. The new stressor doesn’t have to be similar to the original trauma—it just needs to strain your coping resources enough to allow those underlying symptoms to surface.
Brain Changes Over Time
The key brain regions involved in PTSD—the amygdala, hippocampus, and prefrontal cortex—can undergo changes over extended periods following trauma exposure. The amygdala, which acts as your brain’s threat detector, may become progressively more reactive through a process called kindling. Meanwhile, the hippocampus, responsible for memory processing and distinguishing past from present, may show gradual structural changes that make it harder to contextualize traumatic memories appropriately (Shalev et al., 2022).
These biological shifts don’t happen overnight. They develop slowly, influenced by ongoing stress exposure, sleep quality, physical health, and other life circumstances. This is why two people who experienced the same traumatic event might have completely different timelines for symptom onset—their brains and life circumstances diverged after the trauma.
Common Triggers for Delayed Symptoms
For San Diego residents, particularly those connected to our military community, certain life transitions commonly trigger delayed PTSD symptoms:
Retirement or Career Changes: When the structure and identity of military service or a demanding career ends, symptoms that were manageable in a regimented environment can suddenly surface. Without the distraction and routine of work, traumatic memories have more space to emerge.
Reminders Through Media or Community Events: A news story about combat zones, a helicopter flying low over the coast, or even a particular smell at a community gathering can suddenly activate memories you thought were safely stored away.
Significant Life Milestones: Getting married, having children, or experiencing a significant birthday can trigger existential reflections that bring unprocessed trauma to the surface. New parents, in particular, may find themselves confronting past trauma as they consider what they want to protect their children from.
Additional Traumas or Losses: Experiencing a new traumatic event—even something seemingly unrelated like a car accident or medical emergency—can reactivate responses to earlier traumas.
Physical Health Changes: Aging, neurodegenerative conditions, or significant health diagnoses can reduce the cognitive resources available to keep traumatic memories compartmentalized, allowing symptoms to emerge (Shalev et al., 2022).
Recognizing the Signs in Yourself
Delayed-onset PTSD includes the same core symptoms as immediate-onset PTSD, but you might not connect them to your past trauma at first. Watch for:
- Intrusive memories or nightmares that seem to come from nowhere
- Heightened startle response to sounds or sudden movements
- Avoiding people, places, or situations without knowing exactly why
- Feeling emotionally numb or disconnected from loved ones
- Difficulty concentrating or completing tasks you used to handle easily
- Hypervigilance—constantly scanning your environment for threats
- Irritability or angry outbursts that feel disproportionate to the situation
The key difference with delayed onset is timing. If these symptoms emerged or significantly intensified months or years after your traumatic experience, especially following other life stressors, delayed-onset PTSD may explain what you’re experiencing.
What You Can Do This Week
- Document Your Timeline: Write down when your trauma occurred and when you first noticed symptoms—even small ones. Note any major life events that happened around the time symptoms intensified. This timeline can be incredibly helpful for treatment providers in understanding your experience.
- Talk to Someone You Trust: Share your observations with a close friend, family member, or spiritual advisor. Simply naming what you’re experiencing can reduce the shame and confusion that often accompanies delayed symptoms. You don’t need to have everything figured out—just start the conversation.
- Research Local Resources: Here in San Diego, you have access to specialized trauma treatment options. Look into providers who understand the unique needs of our military and veteran community, as well as civilians who’ve experienced trauma. Many facilities, including those specializing in innovative treatments, offer free consultations to discuss whether their approach might help.
When Professional Help Makes Sense
Not everyone who experiences delayed symptoms needs intensive treatment, but professional support can prevent symptoms from worsening and help you regain quality of life. Consider reaching out to a mental health provider if:
- Symptoms are interfering with your relationships, work, or daily functioning
- You’re using alcohol, substances, or other behaviors to cope with distress
- You’re having thoughts of self-harm or suicide
- You’ve tried managing symptoms on your own without improvement
At West Coast Ketamine Center, we’ve worked with San Diego residents for over 20 years, specializing in treatment for PTSD and other mood disorders. Our team includes both board-certified psychiatrists and anesthesiologists, ensuring comprehensive care that addresses both the psychological and physiological aspects of trauma recovery. We understand that seeking help years after your trauma can feel complicated—Why now? Why didn’t this bother me before?—and we’re here to help you make sense of your experience without judgment.
Treatment approaches vary by individual, and results differ from person to person. What works for one person may not work for another, which is why thorough assessment and personalized treatment planning matter. The goal isn’t to erase your trauma or guarantee specific outcomes, but to help you develop the tools and support to manage symptoms and reclaim your life.
Moving Forward
Discovering that you have delayed-onset PTSD can actually be a relief. It means what you’re experiencing has a name, a biological basis, and most importantly—effective treatment options exist. You’re not “going crazy,” you’re not weak for not “getting over it,” and you’re definitely not alone.
Your brain did what it needed to do to protect you when the trauma occurred. Now, years later, it may need support processing what happened in a new way. That’s not failure—that’s being human.
If you’re in the San Diego area and experiencing delayed PTSD symptoms, we invite you to reach out. Whether or not our treatment approach is right for you, we can help you understand your options and point you toward appropriate resources. Your trauma may be years behind you, but your healing journey can start today.
References
Andrews, B., Brewin, C. R., Philpott, R., & Stewart, L. (2007). Delayed-onset posttraumatic stress disorder: A systematic review of the evidence. American Journal of Psychiatry, 164(9), 1319-1326. https://psychiatryonline.org/doi/10.1176/appi.ajp.2007.06091491
Bonde, J. P. E., Jensen, J. H., Smid, G. E., et al. (2022). Time course of symptoms in posttraumatic stress disorder with delayed expression: A systematic review. Acta Psychiatrica Scandinavica, 145, 116-131. https://onlinelibrary.wiley.com/doi/full/10.1111/acps.13372
Shalev, G. I., Liberzon, I., Lebois, L. A. M., et al. (2022). Neurobiological mechanisms underlying delayed expression of posttraumatic stress disorder: A scoping review. World Journal of Psychiatry, 12(1), 18-38. https://pmc.ncbi.nlm.nih.gov/articles/PMC8783158/
