Abstract
Background: Different studies have documented positive associations between adverse childhood experiences (ACE) and psychoactive substance use disorder; arousability and sleep disorders; as well as positive associations between ACE and sleep disorders. There isa need to explore possible associations among ACE, arousability, and sleep disorders specifically in patients with substance use disorder in our local environment, hence this study. The objectives of the study were to determine the associations between ACE (on the one hand); arousability, and sleep disorders (on the other hand) in patients with substance use disorder. The other objective was to explore possible associations between arousability and sleep disorders in the same group of patients. The sleep disorders of interest in this study are insomnia, excessive daytime sleepiness (EDS), and poor sleep quality.
Methods: Eighty-four (84) subjects who met the ICD-10 criteria for the diagnosis of psychoactive substance dependence from the Department of Mental Health, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, were consecutively recruited into the study. They were required to complete: Proforma on sociodemographic characteristics and drug use information; Adverse Childhood Experiences Questionnaire (ACE-Q); Arousal Predisposition Scale (APS); Insomnia Severity Index (ISI); Epworth Sleepiness Scale (ESS); and Pittsburgh Sleep Quality Index (PSQI). The data were analyzed using SPSS, version 23, and P˂ 0.01 was considered significant.
Results: Eighty-two (82) of the subjects, representing 97.6 % of the total number, provided complete data for analyses. The age range of the 82 participants was from 19- 44 years, with a mean of 28.5 years (SD=7.3, SEM =0.8). There were 77 males (93.9 %) and five females (6.1 %).
A total of 15 out of the 82 subjects (18.3 %) recorded ≥4 in ACE- Q. Twenty-one (25.6 %) met the requirement for arousability using the APS, 17 (20.7 %) had clinical insomnia, 22 (26.8 %) had EDS, while another 22 (26.8 %) had poor sleep quality. The common drugs of dependence used by the subjects were alcohol, cannabis, cocaine, methamphetamine, nicotine, opioids, and sedatives/hypnotics; either alone or in
combination. The results showed that ACE was positively and significantly associated with arousability (χ 2 = 13.713, df =1, P = 0.000), insomnia severity (χ 2 = 20.274, df =1, P = 0.000), EDS (χ 2 = 12.461, df =1, P = 0.000), and poor sleep quality (χ 2 = 12.461, df =1, P = 0.000). There was a positive association between arousability and insomnia severity, a positive association between arousability and EDS, and a positive association between arousability and poor sleep quality.
Conclusion: The findings showed that ACE and arousability may be significant factors contributing to sleep disorders among subjects with substance use disorders. The study therefore concludes that prevention of adverse experiences in childhood and adolescence is pivotal to the prevention of subsets of sleep disorders, in adult life.

Key words: Adverse childhood experiences, arousal predisposition, arousability, sleep disorders, substance use disorder, psychoactive substance dependence.