What Are PTSD Flashbacks And What Triggers Them?

Flashbacks are one of the most well-known symptoms of post-traumatic stress disorder (PTSD). They can cause significant distress and may reduce a person's quality of life. Here, we’ll discuss what PTSD flashbacks are, how they are triggered, what neural mechanisms function during flashbacks and how they can be treated.

What are PTSD flashbacks?

Flashbacks generally belong to the category of "re-experiencing symptoms" in the PTSD diagnostic criteria, which can also include nightmares and other forms of intrusive memories. They can be described as involuntary, intrusive recollections of the traumatic event experienced, which cause the person to feel like it’s happening all over again. Because of how real flashbacks can feel, people may experience powerful physical and mental symptoms during them—as if they were actually in that time and place again.

Currently, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and the International Classification of Diseases, 11th Revision (ICD-11) propose that flashbacks can exist on a continuum—that is, that they can be fleeting intrusive memories, extreme episodes of loss of contact with surroundings due to re-experiencing, or anywhere in between. However, many people with post-traumatic stress disorder have described their flashbacks as being different from any ordinary memory that you can willingly retrieve at any time. 

In flashbacks, people can have a complete or partial reliving of a traumatic event, whereas a different type of memory may be a vague recollection. In contrast to regular memories, flashbacks can come suddenly and take people by surprise. 

What might trigger a PTSD flashback?

Some flashbacks can be unprovoked, but they can also be brought on by specific triggers. A PTSD trigger is a broad term for anything that can remind a person of a traumatic event and “trigger” specific symptoms. Triggers for flashbacks can be diverse and are unique to the individual, and they may include stimuli such as people, places, objects, words, and even smells or sounds.

For example, an unexpected loud sound or the smell of smoke might remind a person who grew up in a war zone of their related traumatic experiences in childhood. Because of the triggers, the individual in this scenario might have vivid scenes of that time replaying in their head and may potentially react by performing actions they once did, such as hiding or ducking for cover.

Triggers often affect a person spontaneously and when least expected. Alternatively, some people who have experienced a PTSD panic attack or other intense symptoms might become highly aware of their triggers so they can attempt to stay away from them as much as they can. This is known as avoidance, and it’s part of the criteria for diagnosing people with post-traumatic stress disorder. Avoidance symptoms can be some of the most challenging to manage, as they can reinforce fear of triggers, which could exacerbate all symptoms. While avoidance might provide short-term reassurance, avoiding triggers does not generally offer a suitable long-term solution.

What happens in the brain during PTSD flashbacks?

Flashbacks are neurologically complex. Studies suggest that there might be multiple mechanisms at work that occur when a flashback is taking place. 

One older study published in Psychological Medicine reviewed the experience of 36 Vietnam veterans, 17 of whom had PTSD. These individuals appeared to have reduced activity in the medial prefrontal cortex and increased activity in the amygdala—whereas the 19 who did not have the disorder showed no signs of this. Psychological research is constantly evolving and newer information may be available.

Some additional areas of the brain that have shown increased activity in those with post-traumatic stress disorder are:

• The striatum, responsible for motor and executive function
• The rostral anterior cingulate cortex, which can play a role in the processing of fear and impulses
• The ventral occipital cortex, which may influence perception—specifically via visual stimuli 
• The thalamus, which is considered to be the body’s relay station 

Exploring the physiological response of PTSD flashbacks

When faced with a dangerous or stressful situation, whether real or imagined, the brain initiates its innate survival mechanism: the fight-or-flight response. This stress response exists in other mammals as well and can allow fast reaction to various situations. In nature, this usually means running from danger or defending oneself against it, hence the name.

Here’s how it works: Once the possibly dangerous stimuli has been perceived by the person, the amygdala (which is involved with emotional processing) signals to the hypothalamus that there is a problem or threat. Next, it messages the autonomic nervous system, which can signal a person or animal to react to the situation.

Next, the autonomic nervous system activates. This system oversees vital involuntary processes in the body, such as breathing and heart rate. Within the autonomic nervous system, fight-or-flight is often specifically associated with the sympathetic nervous system, which can then release epinephrine—more commonly known as adrenaline—into the organism's bloodstream. 

Epinephrine can cause physiological responses extremely quickly, which can trigger some into a physically oriented PTSD attack. Some physical symptoms of a post-traumatic stress disorder attack can include:

• Higher blood pressure

• Quicker heart rate

• Faster and heavier breathing

While it can be physically uncomfortable in the moment, these functions can provide energy and oxygen to the body. They can also keep the person fully alert and aware of any other possible threats around them. 

In the last step of the fight-or-flight response, the HPA axis (which contains the hypothalamus (H), pituitary gland (P) and the adrenal glands (A)) can then release hormones through this chain. First, the corticotropin-releasing hormone will travel to the pituitary gland from the hypothalamus, and then the adrenocorticotropic hormone will reach the adrenal glands—which will then release cortisol.

Cortisol levels spike after adrenaline does, keeping the sympathetic nervous system activated and on high alert. When a threat passes, such as when a post-traumatic stress disorder (PTSD) episode ends, cortisol will decrease. The parasympathetic nervous system can then step in and help bring the body to homeostasis, returning the heart and breathing rates back to typical patterns.

Are PTSD flashbacks treatable?

Flashbacks, as distressing as they can be, can be treatable through the use of medication and/or psychotherapy techniques.

Selective serotonin reuptake inhibitors (SSRIs), for example, are a class of antidepressants that can be used to treat a variety of different mental health conditions, such as depression and post-traumatic stress disorder (PTSD). Though they’re not right for everyone, they may be especially helpful in treating symptoms of re-experiencing and avoidance in some individuals. Talk to your doctor before starting, stopping, or changing any medication.

That said, talk therapy is generally considered to be the first-line treatment for PTSD symptoms and is often the most effective long-term treatment method. One reason is that it can help a person with PTSD learn how to manage their symptoms through healthy coping strategies while reprogramming their perception of their triggers. For example, cognitive behavioral therapy (CBT) generally aims to help an individual learn to recognize their negative thoughts and shift them into more productive ones, which can then reduce a trigger’s impact. 

Seeking support for flashbacks and other PTSD symptoms

Again, talk therapy with a licensed professional is often the first recommended treatment method for those with post-traumatic stress disorder, but it’s not possible for everyone to regularly travel to in-person therapy appointments. Some people don’t have qualified providers in their area who are accepting new patients, while others may find it hard to leave home due to their symptoms. In such cases, online therapy can be a more convenient option. 

With a platform like BetterHelp, you can get matched with a licensed therapist who you can meet with via phone, video call, and/or in-app messaging from anywhere you have an internet connection. By reducing some of the barriers to seeking help, such as limited availability, inconvenient commutes, and potentially higher costs, online therapy shows strong promise for people who may avoid reaching out when it feels difficult or stressful.

A growing body of evidence suggests that online therapy can be an effective treatment for symptoms of post-traumatic stress disorder (PTSD). For example, in a study published in the Journal of Anxiety Disorders, 87 college students with rape-related PTSD participated in an interactive program or a self-help program carried out online. After three months, researchers noted significant reductions in PTSD symptoms and high levels of satisfaction with the program and the therapists, as reported by the participants.

Takeaway

PTSD symptoms, regardless of their intensity and frequency, can cause distress for those who experience them. With assistance, intrusive PTSD flashbacks and other mental health symptoms may become less frequent. Therapy is usually the first line of treatment for PTSD symptoms, sometimes in combination with medication. If you’re ready to seek help, you might reach out to a qualified provider to get support online or in person.