The main goal of this study was to expand the literature surrounding substance use in Oman and those who seek treatment as there is little information that currently exists about this population. This study explored socio-demographic factors, factors related to the initiation of substance use, types of substances used, comorbid health and psychiatric conditions, healthcare utilization and hurdles to accessing healthcare among people that use psychoactive substances in a substance use disorder treatment facility in Oman. Other than certain impressionistic observations [2, 6, 28], no specific study on the aforementioned variables has been conducted in Oman before.

In terms of socio-demographic background, this study supports the view that consumption of alcohol and illicit substance use occurs predominantly among males. In previous studies from the US, fewer females than males were reported as struggling with issues relating to substance use [42, 43]. More recently, the narrowing gender gap has also caused the gap in male-female substance use to taper. This trend exists, however, only in ‘wet’ countries, i.e. those countries with relaxed policies toward certain psychotropic substances (such as cannabis) as well as alcohol [44, 45]. It also appears in relatively ‘dry’ countries like Oman, and others that are in transition such as those in Asia, Africa and South America [46–49]. There were only three Omani females that reported seeking therapy for cessation of psychoactive substance use in our study. This observed gender gap in alcohol and illicit substance use in Oman may partly stem from the socio-cultural circumstances of Oman being a patriarchal society that practices strict gender segregation. This. in turn, causes culturally disapproved behaviors among women to be practiced furtively [50].

Regarding the age of onset, most subjects indicated that they first experimented with psychoactive substances between ages 15 and 19. Approximately 16% admitted to starting even younger: between 10 and 14 years. This resonates with the international trend of exposure to controlled substances occurring typically during primary and secondary years of schooling [40, 51, 52]. This study also found that the percentage of substance use was higher among those whose education was limited to secondary or pre-secondary school levels, than among patients that had pursued higher education. In a study conducted in Saudi Arabia, Sheikh et al. [53] examined the quality of life among people that engage in substance use and those that do not. The study found that substance use was associated with lower educational and socio-economic status. This would imply that extending better educational opportunities for everyone might be a possible way of reducing the potential for substance use disorders. On the other hand, early initiation to psychoactive substances might negatively affect the student’s motivation to study further. Future studies should examine the interplay of the aforementioned factors and, additionally, the complex effects of individual differences—such as academic aptitude, intelligence, emotionality, and neurological vulnerability to substance use.

Studies from USA [54], Kuwait [55] and Saudi Arabia [56] have all shown that the availability and type of psychoactive substances, the individual’s personality, and peer pressure strongly influence the initiation of alcohol and substance use. Most of these factors were not explored in this study. A previous study conducted in Oman among a nationally representative school sample concluded that psychoactive substance initiation often occurs in the context of the influence of peers [21]. The present study also indicates a similar trend.

With regard to alcohol, a previous study in Oman [2] has suggested that alcohol use is strongly related to accessibility. According to McCabe et al. [57], the term “polysubstance use” refers to “the use of more than one psychoactive substance during a given period (e.g., 12 months) but not necessarily at the same time” (p 530). In American studies, the 12-month prevalence for polysubstance use was estimated to vary widely from 12.1% [57] to 64.4% [58] and 72.6% [59]. In our study, most patients engaged in polysubstance use.

Intravenous psychoactive substance use has been reported in many parts of the world and appears in different contexts within the Arabian Peninsula as well [6, 60–63]. Data from the World Health Organization, as reported by Panduranga, Al-Abri & Al-Lawati [61], mentions the prevalence of substance use in the Eastern Mediterranean region (which include Oman) to be 3,500/100,000 while prevalence of intravenous substance use disorders is at 172/100,000 people. According to the 2017 report of the United Nations Office on Drugs and Crime, the prevalence of injecting psychoactive substances has been estimated at 0.2% of the population in the region defined as “Near and the Middle East” (which includes Oman) [64]. In the present study, approximately 67% of the participants admitted having used intravenous substances.

The most consumed substances were opioids (including heroin), cannabis and alcohol. As often the case, accessibility defines the type of controlled substances that are more likely to be used. Oman lies close to the opioid and cannabis producing “Golden Crescent” region of Central Asia. Alcohol availability has increased with the influx of expatriate contract workers from different parts of the world who currently constitute about 45% of the total population, majority of whom are young, single men [30, 65]. The growth of the tourism industry has also contributed to easier availability of alcohol [15]. This observation is supported by existing literature [66, 67]. Not surprisingly, availability and accessibility appeared to be major factors that facilitated substance use initiation and dependence among the participants of this study as well.

Substance use has been known to compromise several health parameters, which are likely to worsen if administered intravenously [68, 69]. With reference to the data in 2007 from the WHO’s Oman Atlas of Substance Use Disorders [20], among 384 Omanis that were documented to inject themselves with psychoactive substances, 6.5% had HIV/AIDS, 42.5% had contracted Hepatitis B and 3.9% had Hepatitis C. In our study, Hepatitis C infection was the most common (41.3%) disease, followed by HIV/AIDS (4.1%), Hepatitis B virus (3.1%) and Tuberculosis (0.3%). The trend in Oman appears to echo the situation in regions of Bahrain and Saudi Arabia [62, 63]. If the link between people who inject psychoactive substances and proliferation of the infectious diseases would withstand further scrutiny, Oman ought to contemplate evidence-based prevention [70, 71].

Various studies from the Arabian Gulf have reported a strong link between the presence of psychiatric disorders and personality disorders and the development of substance use disorders [6, 72, 73]. Similar trends have emerged among other populations where the data has unequivocally suggested a higher incidence of psychiatric disorders among people with substance use disorders compared to the general population [74, 75, 76]. What is in question, however, is the direction of causation. One assumption is that substance use is a form of “self-medication for existing mental disorders” [77]. Another assumption is that consuming harmful substances might trigger mental disorders among a vulnerable population [78]. In the present study, 35% of the patients exhibited depressive symptoms while 18% had made suicidal attempts. This view is consonant with the literature suggesting a strong link between depressive symptoms/suicidality and substance use [79–82].

It has been previously documented that individuals in the Arabian Peninsula tend to hide substance use and associated problems partly due to perceived legal consequences and the strong social stigma in Islamic communities, where the consumption/use of any form of alcohol or psychoactive substances is perceived as haram (behavior forbidden by God) [83,84]. Given such background, traditional healing practices and illegal use of prescriptive medicines are rife and remain as the only recourse for people with substance use disorders in Arab countries [6, 85, 86]. Thus, people with substance use disorders in the Arabian Peninsula have been reported as receiving suboptimal rehabilitation, often resulting in relapse and fatalities [56, 87, 88].

In order to lay the groundwork for mitigating such trends, this study sought to identify the pattern of healthcare utilization that included gauging the number of and reasons for outpatient and emergency visits and admissions. The perceived barriers to and outcomes of services were also sought. Indeed, most patients admitted for substance use disorders in Oman appear to do so via emergency units. Relapses are common and associated with re-admissions, severe depression, overdose, and suicide attempts.

Oman, like most countries in the Arab world, represents a collectivistic community where individuals are socialized to suspend ‘selfhood’ for collective wellbeing [50]. Anthropological studies have described such societies as making strong use of honor and shame to enforce socialization and, as a result, individuals are accustomed to being preoccupied with what others think [89]. However, it is important to note here that it may not just be honor and shame being enforced during socialization, but also a promotion of community values, collective well-being, a feeling of belongingness and perceived social support which are all likely to have positive impacts on long-term individual well-being [90]. Nevertheless, while the majority of patients endorsed that the interventions at the rehabilitation center had improved their wellbeing, they were apprehensive of returning to their communities which might now perceive them as an outsider. This prospect appeared to dampen their motivation to attend therapy for cessation.

As with any study, this study also presents its own set of limitations. First, the present sample population of those attending a tertiary care facility might have been self-selective and a convenience sample. Hence, the generalizability is limited. More representative data is likely to emerge from a community study. This is particularly significant for a collectivistic and traditional society like Oman where substance and alcohol use remain furtive activities and rehabilitation is often in response to police/judicial demands or when an individual’s condition has reached advanced stages of pathology. This may explain the preponderance of polysubstance and intravenous substance use within our sample. It is likely that the individuals engaging in substance use and experiencing less acute problems tend not to seek biomedical help. Another limitation is the location of the healthcare unit. Oman has a total land area of 309,500 square kilometers with its population dispersed in different corners of the country separated by vast stretches of desert land. This study is limited to attendees seeking help from a tertiary care center located in the most urbanized northern coastal region of the country. The issue of urban-rural dichotomy was not considered in this study. The length of hospitalization was also not assessed. Studies have indicated a strong positive relationship between the length of hospitalization and good prognostic indicators [91]. Another potential limitation in the analysis is related to stratifying the database by two dichotomous categories of age and not analyzing age as a continuous variable. This dichotomous division simplified the presentation of data and facilitated conducting binary categorical data analysis. As reported by Altman & Royston [41, 92], this approach however, might have introduced the drawbacks of reduction in statistical power to detect a relation between age as a continuous variable and indices of substance use and underestimation of the extent of variation in substance use between Younger and Older groups. There is also the issue of concealment of any non-linearity in the relationship between age as a continuous variable and indices of substance use which might have affected the underlying assumptions of logistic regression modeling done as part of this study. Finally, the study is based on subjective self-reports which are known to be prone to social desirability bias.