What Are PTSD Flashbacks And What Triggers Them?

Flashbacks are known by many as one of the most notable symptoms of post-traumatic stress disorder (PTSD). They can cause significant distress and may reduce a person's quality of life. This article will discuss what PTSD flashbacks are, how they are triggered, what neural mechanisms function during these 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.

In PTSD, flashbacks are described by many as "frequent intrusive recollections of the traumatic event and acting or feeling as though it were happening again." Because of how real flashbacks can feel, people can experience powerful physical and mental symptoms during them—as if they were actually in the time, place and location once again.

Currently, the DSM-5 and the ICD-11 believe that flashbacks can exist in a continuum; however, many people with PTSD 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 memory can 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—however, they can also be brought on by triggers. A PTSD trigger is defined by many as a broad term for anything that can remind a person of a traumatic event. Triggers for flashbacks can be diverse, and may include stimuli such as people, places, objects and words. They can also involve one's senses.

For example: An unexpected loud sound or the smell of smoke might remind a veteran who served on the frontlines of his experiences in a war. Because of the triggers, the individual in this scenario might have vivid scenes of battle replaying in their head and may potentially react by performing actions they once did; such as hiding or ducking for cover.

Many triggers can be spontaneous and can happen when least expected. Alternatively,  some people who have experienced a PTSD panic attack might also become completely aware of their triggers and might attempt to stay away from the ones that they can control as much as they can. This is known as avoidance, and it can be part of the criteria for diagnosing patients with PTSD.

Although it is considered by many to be the natural response to such stressors, avoidance symptoms might be regarded as some of the most challenging to manage—as they might convince people to fear their triggers. 

In cases like this, avoidance can cause triggers to perpetuate. While practicing avoidance might provide short-term reassurance to many that they will be “okay,” avoiding triggers does not generally offer a suitable long-term solution to the issue.

What happens in the brain during PTSD flashbacks?

Flashbacks can be neurologically complex. Many studies currently suggest that there might be multiple mechanisms at work that occur when a flashback is taking place. 

One such study published in Psychological Medicine reviewed the experience of 36 Vietnam veterans—where 17 of them had PTSD, which was showed that through positron emission topography.  These individuals were clinically suggested 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. Some additional areas of the brain that have shown increased activity are:

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

While there is a considerable amount of responsiveness in multiple areas of the brain in many during PTSD flashbacks, the aforementioned study also suggests that others can be reduced as well. 

In addition to the medial prefrontal cortex, the ventromedial prefrontal regions can also be affected in this regard—which can influence one’s ability to control and process emotions

While the list above contains the primary areas of the brain that can be affected in a flashback, there may be others as well. For example: The hippocampus, which is part of the limbic system, houses an important connection with stress and its role in verbal declarative memory. Reduced hippocampal volume can happen during aging, and this area can be damaged by Alzheimer's disease, leading to memory issues. 

Since PTSD involves memories to a great extent, it is hypothesized that the hippocampus has a role in the condition.

Exploring the possible physiological effects of PTSD flashbacks

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

The fight-or-flight response is thought by many to involve a few major parts of the brain, some of which have been discussed. We’ve summarized the fight-or-flight response that many may experience below: 

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 signala person or animal to react to the situation.

You may be wondering: What does the autonomic nervous system do? 

Simply put, the autonomic nervous system is thought by many to oversee vital, yet involuntary processes in the body—such as  one’s 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—also 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 PTSD 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 act after adrenaline does, keeping the sympathetic nervous system activated and on high alert in many. When a threat passes, such as a PTSD episode, 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 in many through the use of medication and/or psychotherapy techniques.

Selective serotonin reuptake inhibitors (SSRIs), for example, are thought by many to be a class of antidepressants that can be used to treat a variety of different mental conditions—such as depression and PTSD. They can be especially helpful in treating symptoms of re-experiencing and avoidance.

However, therapy might be one of the most effective long-term treatment methods, as a person with PTSD can learn how to manage their symptoms through coping strategies while re-programming their perception of their triggers. 

For example, cognitive behavioral therapy (CBT) generally aims to change the person's negative thoughts into more productive ones, which can then reduce a trigger’s impact. Many with PTSD may find that they benefit from this psychotherapeutic process.

Additionally, many may find benefit from addressing avoidance behaviors, which allow a person's fears to exist and get stronger over time. Medication may be needed in some cases, especially during earlier phases of treatment. However, many may find that with intentional action, their responses might improve over time. 

How can online therapy help those living with PTSD? 

At BetterHelp.com, licensed online therapists can be made available to help people living with PTSD and other mental conditions. While many may feel overwhelmed by the prospect of leaving their home to face their fears head on, online therapy is an avenue that can offer comparable benefit within the comfort of one’s home or safe space—possibly being a more available treatment option for many. 

 By mitigating the barriers to seeking help, such as limited availability, inconvenient commutes and potentially higher costs, online therapy shows strong promise for many people who may avoid reaching out when it feels difficult or stressful.

Is online therapy effective? 

Evidence continues to support online therapy as an effective treatment for PTSD and its related symptoms. 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 therapists, as reported by the participants.