In the present study, about 80% of the subjects did not report a reduced availability or an increased price of the illegal drugs heroin, cocaine, or cannabis. The quality of these drugs was evaluated as worse by 28.3% as compared with the period before the lockdown. Furthermore, only a small minority switched from their main drug to legal drugs, especially alcohol, or to illegally acquired medications such as benzodiazepines or gabapentinoids. Only one subject whose main drug was cannabis switched to synthetic cannabinoids, one heroin addict switched to NSOs, and only a few subjects initiated treatment due to a reduced availability of their main drug. In our sample, the lifetime experience of ordering illegal drugs online was low, e.g., <10%, and only two subjects ordered their main drugs for the first time during the COVID-pandemic.

Basic sociodemographic and clinical data (e.g., age around 40; mostly males; and typically polydrug users) of the present sample are consistent with the description of samples of illegal drug-using clients attending German drug services (10); in two recently published investigations carried out in Western parts of Germany addiction clients confirmed that heroin, cocaine, and cannabis were their main illegal drugs (10, 15), with very limited numbers of clients reporting NPS and NSO intake. Typical low-threshold addiction facilities' clients polydrug, including opiates, users. However, drug addicts might define cocaine or cannabis as their main (illegal) drug, especially in the case of maintenance treatment. However, consistent with recent inpatient detoxification treatment data from Western Germany (10), a growing problem of gabapentinoid misuse, predominantly among opioid addicts (16–18), with three participants having identified pregabalin as their main drug, was highlighted here.

Current results are not fully consistent with recent findings about drug abuse during the COVID-19 pandemic (7, 19). In April and May 2020, EMCDDA carried out the “European Web Survey on Drugs: COVID-19” (EWSD-COVID), in which more than 10,000 subjects of at least 18 years of age were asked about their use of illicit drugs (7). Some 46% of respondents reported a reduced use or no drug use during the lockdown. In particular, 20% of cocaine or MDMA users reported to have stopped the use of one of these drugs during the pandemic. In contrast, among current users of illegal drugs (defined as drug consumption during the last 12 months) some 25% reported an increased drug use, especially of cannabis (about 15%) and of alcohol (about 15%). Conversely, the EMCDDA expert opinions regarding availability and price of drugs, albeit not supported by empirical evidence, yielded a heterogeneous picture, with different situations in the different EU countries. Indeed, the price of cannabis was suggested to have increased in several EU member states, in parallel with a decrease in its availability. However, the European Web Survey focused on users of illicit drugs, not only on subjects with a clear drug addiction status.

A further document, elaborated by the EMCDDA in cooperation with Europol (19), concluded that the European drug supply scenario had not significantly reduced during the Covid-19 pandemic. In fact, while air trafficking was vastly reduced, the transport of commercial goods by ship, air freight, and so on had somehow continued during the pandemic, and this may have facilitated the transportation of drugs such as cocaine and heroin. In addition, the domestic production of cannabis in some European countries was not restricted by the COVID-19 pandemic (19). These issues may explain the lack of an overall significant reduction of drug supply during the pandemic, although there may have been illegal drug acquisition issues in some places. In Germany, this overall scenario was confirmed by the Federal Criminal Police Office (Ms. B. Hübner, spokeswoman for the Federal Criminal Police Office). In addition, even during the lockdown, several important drug seizures were successfully carried out in EU countries (18).

Lockdown measures made it more difficult to meet with dealers and friends and this may have led to a breakdown of the local street market for drugs. This could have facilitated the occurrence of other forms of drug trafficking, especially buying of illegal drugs online and delivery of drugs by post and parcel services. According to the EMCDDA (19), however, there was only a small increase in drug buying from the darknet during the pandemic. In our sample of polydrug addicts, including users of opiates, only 2/3 of respondents had internet access at all. Consistently with this, online drug acquisition activities during the pandemic were carried out here only by single individuals. Difficulties handling the web and especially the darknet (20, 21) with the related money transfer issues may have limited the availability of the online acquisition option in the current population of marginalized polydrug drug addicts with minimal resources. Conversely, the online option, which may well-include access to messenger services facilitating drug orders and deliveries, may be an easier option for those with a regular income and a routine use of the web. It must be stressed, though, that during lockdown, the internet and the world wide web also offered opportunities for continued “telehealth” care for patients with mental health issues, including those with substance use problems. This extends to online individual or group therapy (22, 23).

A significant reduction of the clients' main drug availability level was not here reported and this may have arguably reduced the need for a shift to NPS/NSO use. Consistent with this, recent data (10, 15) suggested that while about 40% of drug addicts open to addiction services had a lifetime experience with NPSs—and especially with synthetic cannabinoids—this use was sporadic, due to the often severe side effects experienced, which are a strong argument against repeated levels of use even for experienced drug addicts. As for NSOs, only one heroin user shifted here to the use of these substances; this is fully consistent with recent German data (15), but it contrasts with reports from the USA, where an opioid epidemic is occurring (5). There was also only a small shift toward more alcohol use. Previous studies in the general population in the United States or elsewhere found no sustained increase of alcohol use (24) or even decreases due to the discontinuation of social drinking events (8), and on the individual level, large proportions of subjects either increased or decreased their alcohol use during the pandemic. It must be stressed that in the present study increased alcohol use per se was not investigated, but rather the COVID-19-related shifts away from the main drug.

Finally, although long-term follow-up German studies have suggested that on and off treatment episodes alternate in the life of opiate addicts (25), the substantially unchanged levels of drug availability did prompt the need for the initiation of a new treatment (e.g., maintenance or detoxification treatment) episode in only <10% of interviewees.