From single to multiple: the association of childhood trauma with frequent nightmares among youth.

Objective: Childhood trauma is a known risk factor for frequent nightmares in youth, but the effects of single and multiple traumas remain unclear. This cross-sectional study aimed to investigate the association between single and multiple childhood traumas and frequent nightmares.

Methods: Youth aged 12-25 years completed online questionnaires on childhood trauma and nightmares. Cumulative scores and latent class analyses were used to identify multiple childhood traumas. Logistic regression was used to investigate the association between childhood trauma types and frequent nightmares.

Results: Of the 6145 participants, 27.2 % (n = 1670) reported frequent nightmares during the past year. Adjusted analyses showed emotional abuse (OR: 1.45, 95 %CI: 1.23-1.87) and emotional neglect (OR: 1.19, 95 %CI: 1.03-1.37) significantly increased the risk of nightmares. The risk of frequent nightmares increased with the number of traumas: 26 % for one, 36 % for two, and 51 % for three or more, compared with none. The latent class analysis identified three multiple trauma patterns: "low abuse, low neglect" (n = 3837), "low abuse, high neglect" (n = 2089), and "high abuse, high neglect" (n = 219), with increased nightmares risks of 26 % and 47 % in the latter two, respectively, versus the first. However, no significant difference was observed between "low abuse, high neglect" and "high abuse, high neglect" (OR: 1.17, 95 % CI: 0.85-1.60).

Conclusions: Our findings enhance the understanding of the heterogeneity of childhood trauma and its association with nightmares. Prevention and treatment programs for nightmares should be tailored according to different patterns of childhood trauma.