Who suffers from nightmares the most?

In general, nightmares are a common issue among the population [1, 2]. They occur in about 2 − 8% of adults, although their prevalence tends to decrease with age, being more frequent during childhood (19% of children experience nightmares at least once per week) [3]. Nightmares are also correlated with various diseases such as PTSD (post-traumatic stress disorder) or depression. Depending on the severity of PTSD, nightmares are reported by 19 − 71% of patients [4].

REFERENCES:
[1] Krakow B, Haynes PL, Warner TD, Santana E, Melendrez D, Johnston L. Nightmares, insomnia, and sleep- disordered breathing in fire evacuees seeking treatment for posttraumatic sleep disturbance. Trauma Stress. 2004; 17: 257-268.
[2] Langston TJ. Nightmares and sleep quality in children and adolescents: a comparison based on trauma status (Phd dissertation) USA: University of Tulsa; 2007.
[3] Abdel-Khalek AM. Prevalence rates of report nightmares in a cross-sectional sample of Kuwaiti children, adolescents, undergraduates, and employees. Sleep Hypn. 2010; 12: 13-22.
[4] Maher MJ1, Rego SA, Asnis GM. Sleep disturbances in patients with post-traumatic stress disorder: epidemiology, impact and approaches to management. CNS Drugs. 2006; 20(7): 567-590.