Post-traumatic stress disorder (PTSD) is a well-known mental health problem that can arise a month or more after a person goes through some sort of severe or overwhelming physical\/mental event. Roughly 8 percent of U.S. adults will experience symptoms of the disorder at some point in time. One of the most common symptoms of PTSD is the onset of highly realistic nightmares that echo one or more aspects of the trauma(s) that initially trigger a severe stress reaction. According to the results of an extensive study review conducted in 2012 by the researchers at the Mayo Clinic, use of a common high blood pressure medication called prazosin can significantly reduce the frequency of PTSD-related nightmares. PTSD Basics Generally speaking, post-traumatic stress disorder begins when the body\u2019s built-in compensation mechanisms fail to provide sufficient psychological protection during or after some sort of major traumatic experience. Most people who go through this type of experience don\u2019t develop the disorder, but onset of PTSD is possible whenever extreme trauma occurs. In many cases, the symptoms of the disorder appear very shortly after trauma exposure; however, guidelines established by the American Psychiatric Association require doctors to wait for a full 30 days after exposure before making a diagnosis. People who display symptoms during this 30-day period technically have a condition called acute stress disorder, which either resolves or lingers and essentially turns into PTSD. PTSD and Nightmares Only roughly 5 percent of the adult U.S. population regularly deals with nightmares, the U.S. Department of Veterans Affairs\u2019 National Center for PTSD reports. However, in people who experience major traumas and subsequently develop PTSD, those numbers increase dramatically. At the low end, modern studies indicate that roughly half of all PTSD-affected individuals develop nightmares; at the high end, current estimates indicate that fully 90 percent or more of all people with the disorder experience nightmare-related sleep disturbances. The nightmares associated with PTSD are frequently not the same as the nightmares that commonly affect other people. Instead of featuring strange or fantastic chains of mental events that have little bearing to reality, they can feature detailed, realistic chains of events that closely or exactly reproduce the circumstances of the individual\u2019s waking traumatic experiences. Roughly 50 percent of affected individuals have these types of nightmares. In some cases, the repeated, unwanted reliving of traumatic experiences in dreams can seriously diminish the mental health of PTSD sufferers and substantially increase the risks for such serious secondary problems as substance abuse\/addiction or suicidal thought processes. Effects of Prazosin Use Prazosin is sold in the U.S. under the brand names Minipress and Minipress XL. It belongs to a group of blood pressure medications called alpha-blockers, which achieve their effects by changing the body\u2019s response to an important internal chemical called norepinephrine. Doctors have used the medication since the early 2000s as a treatment for PTSD-related nightmares. In the review released by the Mayo Clinic, a team of researchers analyzed the results of 12 previous studies that assessed the real-world effectiveness of this use. Four of these 12 studies were designed to meet the highest standards for scientific testing, while the remaining eight varied from those standards in some way. Nevertheless, all of the included studies came from reputable, well-organized research efforts. After completing their review, the Mayo Clinic researchers concluded that prazosin is indeed an effective treatment for the nightmares associated with PTSD. When affected individuals start taking the medication, they typically experience a drop in nightmare frequency in a period of days or weeks, and continue to receive benefits from prazosin use over time. However, when use of the medication is discontinued, PTSD-related nightmares usually return to their previous level of frequency. Considerations Apparently, prazosin achieves its nightmare-related effects by preventing an overstimulation of the brain\u2019s circuits that can increase the likelihood of bad dreams. Potential side effects of using the medication include nausea, unusual fatigue or weakness, headaches, heartbeat abnormalities, chest pain, hives or other skin eruptions, breathing problems and painful, extended erections in men. However, the authors of the Mayo Clinic study review concluded that these side effects don\u2019t typically become serious enough to interfere with prazosin\u2019s usefulness in PTSD treatment. In fact, they believe that prazosin may ultimately prove useful in the relief of nightmares that aren\u2019t related to the presence of post-traumatic stress disorder.