Publication - Research and analysis

Understanding the patterns of use, motives, and harms of new psychoactive substances in Scotland

Published: 30 Nov 2016
Population Health Directorate
Part of:
Health and social care, Research

This report presents the results of mixed methods research on new psychoactive substance use.

133 page PDF

2.3 MB

133 page PDF

2.3 MB

Understanding the patterns of use, motives, and harms of new psychoactive substances in Scotland
6. Treatment and Legislative Responses

133 page PDF

2.3 MB

6. Treatment and Legislative Responses

6.1 Introduction

This final findings chapter addresses the views of people who have used NPS and staff who support NPS users in treatment. It explores how people who have taken NPS utilise available treatment services, where they currently get information on NPS and what changes they would like to see in available treatment. It finishes with a brief discussion of views on the Psychoactive Substances Act 2016.

6.2 Contact with Services

Reflecting the fact that over half of the data collection was carried out through services (59%, n=251) current contact with services was high across all groups. However, contact specifically related to NPS use was low. Only 11% (n=26) of participants were in contact with one or more services relating to their NPS use.

6.2.1 Contact with services: service type

Fig. 6.1 displays the services that people who had used NPS were most in contact with. The most commonly accessed were: drug services (58%, n=113), mental health services (43%, n=85) and homelessness services (39%, n=74). The least utilised services were sexual health services (8%, n=15), mutual aid (22%, n=44), needle exchange (26%, n=47) and social work (28%, n=54).

Fig. 6.1: Service use by people who have taken NPS by service type

Fig. 6.1: Service use by people who have taken NPS by service type

Base (respondents who reported NPS use: sexual health n=180, mutual aid n=198, needle exchange n=179, social work n=195, homelessness n=192, mental health n=196, drug n=194) [137]

6.2.2 Contact with Services: by group

Rates of service use also varied by group. This section outlines service use in relation to each of the key groups who participated in the NPS survey. [138] Table 6.1 displays service contact data by group.

Table. 6.1: Service use by people who have taken NPS by service type

Group NPS related service contact Type of service accessed for NPS Not in contact with service regarding NPS use Type of services accessed (not NPS related) p-value

6% (n=2) Mutual Aid (6%, n=2)

Drug Services (4%, n=1)

Sexual Health (4%, n=1)
94% (n=30) Mutual Aid (10%, n=3)

Drug Services (25%, n=7)

Sexual Health (30%, n=8)


Homeless (n=74) 11% (n=8) Drug Services (11%, n=8)

Homelessness (3%, n=2)
89% (n=66) Drug Services (69%, n=50)

Homelessness (68%, n=49)

PWID (n=127) 13% (n=16) Drug Services (7%, n=8)

IEP (3%, n=4)

Homelessness (1%, n=1)

Social Work (0%, n=0)
87% (n=111) Drug Services (82%, n=98)

IEP (42%, n=47)

Homelessness (50%, n= 58)

Social Work (34%, n=40)



PWID ( NPS-injectors) (n=42) 19% (n=8) IEP (11%, n=4)

Drug Service (5%, n=2)

Homelessness (0%, n=0)

81% (n=34) IEP (51%, n=19)

Drug Services (79%, n=30)

Homelessness (67%, n=24)


Vulnerable Young People

14% (n=5) Drug Services (7%, n=2)

Other (10%, n=1)
86% (n=30) Drug Services (30%, n=8)

Other (30%, n=3)

Mental Health Service Users

20% (n=18) Mental Health (10%, n=9)

Social Work (6%, n=5)

Drug Services (6%, n=5)
80% (n=72) Mental Health (90%, n=85)

Social Work (41%, n=36)

Drug Services (74%, n=67)



6.2.3 Contact with Services: Reasons for not accessing support

Of the 204 NPS survey respondents who reported that they were not currently in touch with services about their NPS use, 34 provided further information on their reasons for not accessing support.

The most common reasons, which were consistent across all groups, were:

  • I don't have a problem (n=18)
  • I don't need help (n=9)
  • I am in recovery (n=9)
  • I don't know where to go for support (n=3)
  • There is nothing available for people who use legal highs (n=3)
  • I don't want to be seen there (n=3)

6.2.4 Use of emergency services

The survey data suggest that in the main, people who have taken NPS did not consider their NPS use as a reason to contact services. However, considerable numbers across all groups did rely on emergency services such as Accident & Emergency (A&E) and ambulances as a result of their use as described below in Table 6.2. Across all respondents:

  • 32% (n=77) had called an ambulance for another person who had taken NPS, and
  • 23% (n=55) had had an ambulance called for themselves.

Table 6.2 : use of emergency services in relation to NPS use

Total YP MH Homeless PWID MSM

N (%) N (%) N (%) N (%) N (%) N (%)
Had an ambulance called for themselves as a result of NPS use 55 (23%) 12 (35%) 28 (30%) 23 (31%) 34 (25%) 6 (19%)
Called an ambulance for another person affected by NPS use 77 (32%) 12 (35%) 40 (45%) 29 (39%) 51 (38%) 6 (19%)
Attended A&E as a result of NPS use 63 (26%) 14 (41%) 34 (38%) 23 (31%) 38 (30%) 8 (26%)
Been admitted to hospital for more than one night as a result of NPS use 44 (18%) 5 (15%) 21 (23%) 14 (19%) 29 (22%) 7 (22%)

Considering emergency service use by group (also shown in Table 6.2), mental health service users [139] were most likely to call an ambulance for someone else (45% vs., group average of 32%), and MSM the least likely (19%). [140]

Looking specifically at PWID, and comparing those who inject NPS and PWID as a group more widely, some differences emerged. Table 6.3 highlights that NPS injectors were more likely than the wider PWID group to have had an ambulance called for themselves (40% vs. 25%) [139] and for another person (48% vs. 38%). [140]

Table 6.3: comparison of PWID respondents' use of emergency services for NPS use

PWID - NPS injectors PWID - all injectors

N % N %
Had an ambulance called for themselves as a result of NPS use 18 40 34 25
Called an ambulance for another person affected by NPS use 21 48 51 38
Attended A&E as a result of NPS use 20 48 38 30
Been admitted to hospital for more than one night as a result of NPS use 15 35 29 22

Looking at figures from both tables here, overall, rates for visiting A&E in relation to NPS use were high amongst respondents considered as vulnerable young people (41% vs. wider rate of 26%) [140] and respondents who utilise mental health services (38%) [140] . A&E attendance was also higher for NPS injectors (48%) [139] than injectors more generally (30%), as was hospital admission for more than one night (35% of NPS injectors vs. 22% of general injectors, and a wider rate of 18%) [140] .

6.3 Providing Information and Support

6.3.1 Sources of information used by people who use NPS

216 NPS survey respondents answered a question on their sources of information about NPS.

  • 31% (n=67) had not tried to find out about NPS at all
  • 32% (n=70) spoke to friends, family and people they used with
  • 19% (n=41) sourced information from online forums
  • 16% (n=35) had accessed information leaflets
  • 16% (n=34) had talked to a drug service
  • 16% (n=34) had obtained information on NPS from TV documentaries, and
  • 12% (n=27) had sourced information from online social media.

As many participants cited documentaries as a source of information (16%, n=34) as speaking to drug service staff (16%, n=34) or sourcing information from leaflets accessed in drug services (16%, n=35).

These figures reflect findings from the interviews, where participants stated that the main sources of information about NPS were friends or people that participants used with ( "I had asked him what sort of, you know, what would I feel etc")[141], and online forums ("I do a lot of reading online if I was ever going to get something") [142] .

Leaflets from drug services were also identified in qualitative interviews, although this tended to be where people were already engaged with services:

"When I'm along at the needle exchange I'll pick up the leaflets that they've got sitting [there]." [141]

Watching documentaries as a source of information and awareness of NPS harms was a theme that also came up in qualitative interviews:

"I watched a documentary on it on [ TV programme], I don't know if you've ever watched it, but like about four or five times a night paramedics were getting called out for folk that were like having a legal high." [143]

When discussing documentaries, interviewees often focused on the emotional impact the stories presented had on them, and the way they prompted them to assess their own practice in relation to what they had seen on the screen:

"I watched this legal highs documentary that was really insightful and I really believe that had a lot to do with helping me because there was this couple… I was like that girl, and I was watching it with him and he looked like him as well, he really looked like him." [144]

Documentaries on television were a popular source of information, and one which appeared to resonate emotionally with survey participants in a way that other forms of information sharing did not.

6.3.2 Providing Information: Service provider knowledge of NPS

The interviews and focus groups also gave an insight into the views of staff and those who had taken NPS about levels of NPS-specific knowledge within drug services. Interviews with participants who had taken NPS revealed a strong sense that drug services lacked sufficient knowledge of NPS to provide adequate information and support.

A typical response was:

"They [drug service] didn't know enough about the synthetics [synthetic cannabinoids]. They knew bits and pieces maybe about powders and pills and they didn't know enough about synthetics to help me." [145]

Both staff participating in focus groups and interviewees felt that drug services overall had less of an understanding of NPS than other, more traditional drugs:

"Traditionally we'll say 'Heroin: this is the side effects, this is this, this is that, this is the withdrawal symptoms…' but because there's such a plethora of different chemicals and changing chemicals, what are you going to do?" [146]

"It's just recently everybody seems to [be] taking them [ NPS] so they [services] probably don't ken much about them. The likes of kit [heroin] and all that, they sort of know the stages, like what you're going to be like if you never had the stuff, but with that [ NPS] they don't really ken [know]" [147]

This was understood by staff members as stemming from a lack of access to up-to-date information and training, but, critically, also from the continuously evolving nature of NPS:

"The type of NPSs out there, it's forever evolving, forever changing and it's being able to access up to date information". [148]

Focus group participants expressed concerns about their own lack of knowledge, and consequent difficulties in providing reliable information to service users. At the same time, NPS survey participants did not see drug services as the only (or indeed primary) source of information on NPS.

6.3.3 Providing Support: Client disclosure of NPS Use

Three quarters of surveyed staff across all services reported that they always or often asked clients about NPS use when they first presented (75%, n=131). An even higher proportion probed for NPS use when asking clients about their drug and alcohol use more generally (85%, n=149). Building on this initial contact with clients, respondents to the staff survey reported that they were always or often likely to enquire about NPS use at routine appointments (60%, n=100), and at review meetings (63%, n=105). Within the survey it was not possible to identify exactly how workers asked about NPS and it is important to bear in mind that there is some confusion among people who use NPS about what is considered a NPS [149] . This should be considered when drawing conclusions about disclosure of NPS use.

In focus group discussion, service providers described a reluctance from clients to disclose NPS use, and discussed a range of challenges faced in developing and delivering services to support people who are experiencing problems related to NPS use. Most focus group participants described asking about NPS use directly, although some, while doing outreach work, opted for more indirect approaches. The key theme that emerged from focus group discussion was the importance of asking directly. A shared perception across focus groups was that users rarely disclosed their NPS use without being asked:

"We've actually got to ask that extra question to say do you use NPS or legal highs as they would know it? Because if we don't they don't tell us". [150]

This is significant given NPS users' responses that they did not disclose NPS use at drug services.

For staff within most services (social work being a notable exception), direct questions provided positive results, with participants across a range of services explaining that "I usually just ask them directly and they will just say yes" [151] or that "Mine will tell you". [152] When asked directly, outside of social work contexts, many people who use NPS appeared happy to disclose their use, but did not routinely volunteer that information. The context in which this most frequently occurred was as part of a discussion about drug and alcohol use more generally.

6.3.4 Providing support: Client-service user relationships

Again, the interviews and focus group data provided a more detailed insight into the views of staff and people who had taken NPS. This suggested that services sometimes struggled to support their clients in the context of NPS' fast-moving nature and consequent lack of easily accessible, up-to-date information for staff. Some focus group contributors found that this led to difficulties providing services either directly or through signposting. However, others described strategies which focused on playing to organisational strengths:

"We've certainly had to adapt our service because of the prevalence of NPS and the approach we take is we'll use Motivational Interviewing then we'll look at building a relapse prevention strategy with them, look at other supports you can put in place…. With other drugs there is treatment pathways that you can go down, whereas for us we've got to rely on the skills within the team to try and manage that and get them to take control of it." [153]

However, in common with the popularity of documentaries as a source of information which resonated in particularly emotional (rather than safety) terms, interviewees who made suggestions about how to improve services emphasised not particular treatment approaches, but rather the importance of meaningful relationships between staff and service users, and spoke highly of individual workers ( "My worker, she really takes her time and she'll get to the bottom of a problem") [154] and the importance of ongoing relationships:

"Keeping the same support worker because there's nothing worse telling your story to one person and getting it changed and having to say it again" [155]

"[Support service] was a safe place to go. But they didn't…they couldn't educate me on the legal highs. But the people in there were great. They saved my life." [156]

This is consistent with other research which shows that 'alliance' (the bond between client and therapist) is an important factor in successful therapeutic encounters [157] .

6.4 Improving Services

6.4.1 Service Development: NPS Survey respondent perceptions

246 of NPS users responded to the question 'Which one of the following do you think is the most important to be offered to NPS users' ( Figure 6.2).

Fig. 6.2: NPS survey respondent opinion on the key area for service development

Fig. 6.2: NPS survey respondent opinion on the key area for service development

Base: n=246

As illustrated in Figure 6.2 the most popular suggestion for improving services was greater provision of detox and rehabilitation services (27%, n=66). This was the number one priority across all groups except MSM, who prioritised harm reduction:

  • Of the 137 PWID who replied 53 (39%) felt detox/rehabilitation was the most important
  • Of the 94 people in contact with mental health services who replied 32 (34%) felt detox/rehabilitation was the most important
  • Of the 75 people homeless people who replied 28 (37%) felt detox/rehabilitation was the most important
  • Of the 38 vulnerable young people who replied 10 (26%) felt detox/rehabilitation was the most important, and
  • Of the 38 MSM who replied 6 (16%) felt detox/rehabilitation was the most important.

Dedicated NPS specialist services were welcomed by many:

  • Of the 94 people in contact with mental health services who replied, 19 (20%) felt NPS specialist services were the most important, and
  • Of the 75 people homeless people who replied, 14 (19%) felt NPS specialist services were the most important.

Harm reduction (e.g. advice and equipment) was popular amongst respondents who reported injecting drugs and MSM . This was the case for 27 (20%) of the 137 PWID who responded to this question and 8 of the 38 (21%) MSM group.

Specialist staff within existing services was also popular amongst some respondents who reported injecting drugs and amongst vulnerable young people:

  • Of the 137 PWID who replied 14 (10%) felt a specialist within the existing service was the most important, and
  • Of the 38 vulnerable young people who replied 8 (21%) felt a specialist within the existing service was the most important.

The least popular suggestion for improving services was community support (such as counselling and mutual aid), with less than 10% of all NPS survey respondents identifying it as an effective means to support people affected by NPS use.

6.4.2 Service Development: Staff perceptions

Respondents to the staff survey reported a range of resources in their services [158] .

These included:

  • staff who had basic training in NPS (63%, n=115)
  • one-to-one counselling (48%, n=89), and
  • leaflets (48%, n=88).

This suggests there are some potential areas of mismatch between what people who use NPS want and what is currently available or accessible to them. Staff reported that in their service, they would like to be able to:

  • refer their clients to a local specialist service (47%, n=87)
  • offer an NPS specialist within the service (45%, n=82)
  • offer leaflets (40%, n=73).

This suggests a much stronger overlap between what NPS survey respondents consider to be important, notably dedicated specialist services and specialists within existing services, and what staff would like to be able to offer. Figure 6.3. gives a breakdown of what staff currently offer and would like to offer.

Fig. 6.3: Types of services: staff reports of services currently provided and would like to provide

Fig. 6.3: Types of services: staff reports of services currently provided and would like to provide

Base: (n=184)

The barriers staff identified to delivering optimal services were primarily:

  • Lack of specialist NPS detoxification services (45%, n=83) (overlapping strongly with NPS survey suggestions for improving treatment)
  • Lack of specialist NPS treatment services (42%, n=78) (again overlapping strongly with suggestions made by NPS survey respondents for improving treatment), and
  • Funding cuts (44%, n=81).

Overstretched resources led one interview respondent feeling under-supported in his primary service of choice:

"Here at [Sexual health charity] they're very stretched. They might have time to see me once a week but with bipolar, I'm sorry with BPD, you're all over the place and it might strike you in the middle of the night" [159]

6.4.3 Improving Services: access to information

Access to up-to-date information emerged as a key theme in both interviews and focus groups. One solution proposed by the GGC focus group was the development of an app for use by both services and users, which could be easily updated:

"Participant 1: I think if people are reluctant to come forward and use addiction services then they need to focus online for support. Most people have got a PC or a tablet or a phone and if it's not a traditional kind of group of people that would want to access services face-to-face then they need to put online resources, whether that's education, information, whether it's forums where people can share their personal experience or a variety of that.

Participant 2: Or an App.

Participant 1: That's the way forward.

Participant 2: I think that's brilliant, get an App and just do that and they're in it. That's what they need." [160]

Suggestions such as this would not only provide a resource for staff and the large majority of NPS survey respondents who are not accessing services for their NPS use, but also provide information in an easily accessible way. As one young person noted in relation to poster campaigns:

"The bulk of people I knew that take it [synthetic cannabinoids] were mostly always hanging about the town and the only places you see stuff for drugs and that are hospitals and community centers and stuff like that, but places we hang about like McDonalds and that… there's no really that much about there that they can get drug advice". [161]

These views suggest a need to continue and potentially expand outreach work, as well as to explore other new technologies and mediums to engage such as 'apps', and other online resources. However, the NPS survey illustrated that uptake of government-funded online resources such as FRANK and Know the Score was low amongst people who had taken NPS. Only 6% (n=13) reported utilising these resources, compared to 19% (n=41) who obtained information from online peer-led forums. Thus while the development of an app or online resource would likely be of interest to some people who use NPS, and may be of value to staff working with this specific population, it may not attract the numbers that peer-led resources do.

6.5 The Psychoactive Substances Act

The Psychoactive Substances Act ( PSA) scheduled for implementation in April 2016 came into force on 26 May 2016, after all interviews and focus groups had been conducted and the survey period was nearly complete. Therefore, the qualitative data and majority of survey responses are from a perspective of anticipated change.

6.5.1 Introduction of PSA: NPS Survey Respondent Perspectives

As outlined in Chapter 4, knowledge of the legal status of specific substances was not consistent, and 6% (n=26) of NPS survey participants stated that they did not know if they took NPS or not. Similarly, many interviewees appeared unaware of the then-forthcoming PSA:

Interviewer: There's a ban coming in, in April.

" Peter: Ooft, I don't believe that man, it only took them about 4 year…. I think that's an amazing idea." [162]

Or unclear about what it would mean:

Interviewer: Do you know much about the ban that's coming in?

"Tiffany: All I know is that there's a blanket ban on all legal highs, whatever that means, I don't know" [163] .

Any discussion of views on the impact of the legislation must therefore be caveated with an acknowledgement that not all participants were fully aware of issues surrounding legality of NPS.

249 NPS users provided information on how the PSA might impact on their personal NPS use. Over half of NPS survey participants (57%, n=141) reported that the legislation would have no impact. This opinion was consistent across all groups but was highest amongst MSM respondents, with three quarters expecting the PSA to have no impact (74%, n=28) [164] .

However of the 249 people who responded to the question on possible impact, others anticipated that in terms of their personal use they would:

  • move or return to using traditional drugs (29%, n=73)
  • buy from a dealer (21%, n=52).

A further 7% (n=17) thought that they would try something else. Only 6% (n=15) thought that they would stop using NPS altogether [165] .

Despite low levels of people reporting their expectations of stopping NPS use, the ban was eagerly anticipated by some in the interviews ( "I'm just hanging on 'til April [2016, then expected start of the ban]. Once that's out the shops, I don't know anybody I can go to") [166] .

Other anticipated effects of the PSA related to availability (see Fig.6.4).

248 NPS users responded to a question on where they sourced NPS:

  • 45% (n=112) reported purchasing from shops
  • 37% (n=91) reported purchasing from dealers
  • 34% (n=83) reported purchasing from friends or family, and
  • 14% (n=34) purchased NPS online.

The primacy of shops as a source of NPS was consistent across groups, with MSM buying from shops at a slightly lower rate (43%, n=13), compared with people who inject drugs buying from shops at a slightly higher rate (48%, n=67, compared to the average of 45%). [167]

Fig.6.4 : Source of NPS

Fig.6.4: Source of NPS

Base (n=248)

One consequence of the PSA having now come into effect is that it is an offence for shops to sell NPS [168] . Many areas of Scotland had already instigated headshop closures locally through Trading Standards action at the time of data collection. 41% (n=75) of staff surveyed reported that this had already occurred in their area, but a further 37% (n=68) did not know the current status of headshops locally.

When asked about the impact of the PSA on sourcing NPS, 21% (n=52) thought they would buy NPS from a dealer, and 7% (n=18) thought they would buy NPS online. Buying from a dealer was highest among homeless people (33%, n=25) [169] A potential risk of this was highlighted in interviews with regards to purity:

"When the ban comes in, I mean people are going to sell you anything and tell you it's legal highs and you're not going to know any difference" [170]

This suggests that based on anticipated future behaviour, vulnerable groups who take NPS are more likely to continue to use NPS and source either from dealers or directly online than stop use. This entails some risks for people who use NPS:

"How would you regulate that…? Well it will just go underground then. It's got to. Prohibition, know what I mean? Come on. Then it would be dangerous. Think about it. I'm saying this to the Scottish Government, here and now, if you're going to ban these then it's going to go underground and it's going to get even more dangerous than it is the now." [171]

6.5.2 Introduction of PSA: Staff views

The staff responses shared some similar themes with NPS survey responses. Around half of staff who responded to the survey anticipated that their clients would continue to take NPS (56%, n=103), but would shift to sourcing via dealers (35%, n=64), and online (49%, n=91). However, a much higher proportion (46%, n=84), thought clients would return to using traditional drugs.

A final consequence of the PSA coming into effect, and potentially driving NPS use underground, was raised:

"It's hard enough now to get a disclosure, you know, and to maybe put some support in place is going to be worse, people will not disclose, you know and it could become more problematic by the time it comes to that. I don't think it's going to work." [172]

As discussed earlier disclosure was already felt by many staff to be a challenge to service delivery and one which some felt risked becoming even more difficult after the PSA came into effect.

6.6 Discussion

Rates of contact regarding NPS use were particularly low, indicating that people who are using drug treatment and other services, are not talking to these services about their NPS use.

Low levels of contact with social work, mutual aid, and drug, homeless, mental and sexual health services were reported. Use of ambulance and A&E services related to NPS use was considerably higher, particularly among people who inject drugs. It should also be noted that 36% (n=69) of NPS users who answered treatment related questions were not in contact with drug services at all.

The low levels of contact with services for NPS suggests that there is a need not only to raise the profile of available NPS support within services, and to work to develop that support, but also to ensure that staff are adequately trained to ask about and respond to NPS use. This should include staff working in emergency care given the rates of NPS users that reported presenting at emergency departments. As identified in the staff focus groups, asking directly about NPS use was important, and may involve reviewing standard assessment paperwork and procedures, which often ask about NPS use as part of a drug history. A desire for specialist treatment responses was highlighted by both NPS and staff survey respondents. What those services could look like and what adaptions could be made to existing services may be useful to explore.

Sources of information and the fast-changing nature of NPS highlighted information needs for both staff and NPS users. There is already a cohort of people who use NPS who derive significant value from providing clear, detailed accounts of use to facilitate safe use among others [173] . Such a population of users represent a potential resource for others and demonstrate a peer education model that could be applied for other groups. Leaflets were as popular a source of information as talking to staff, and also popular were documentaries, which highlighted that a range of information forms could be useful for different groups. Research conducted by drug charity Lifeline into awareness campaigns, found that use of film in the form of cartoons was highlighted by service users as a potential way of reaching people including vulnerable young people and those with literacy barriers. [174]

Some services struggled around providing effective NPS specific treatment options, and focused on existing approaches such as Motivational Interviewing. Interviewees who had taken NPS, by contrast, did not express views on this but rather emphasised the importance of continuity of care between service user and service provider and the impact of individual key workers. This is confirmed by other studies, which find appropriate treatment, and finding staff motivating, are a key element in satisfaction with treatment by service users. [175]

Finally, NPS and staff survey respondents articulated broadly similar views on the impact of the Psychoactive Substances Act. Both groups saw NPS users shifting back to or towards traditional drug use, and among those who maintained NPS use, a shift from purchasing via shop to purchasing via dealers. Few NPS survey respondents anticipated moving to buying online, which is in contrast to what might be expected from recent research into drug purchases on the dark net [176] or staff expectations. Many of the participants here were unstably accommodated and therefore most likely lacking Internet access to successfully navigate online drug purchases.

Online drug markets often rely on buyer feedback to rate vendors, ensuring an overall emphasis on quality and purity [177] to maintain good vendor reputation. This eBay-like approach is not adopted in street sales, where buyers are much more vulnerable to the inclusion of impurities in or 'cutting' of the substances purchased, and even the substance purchased not being what they expected to buy [178] . This could be a significant consequence of the shift from purchasing primarily via shops to dealers amongst the populations discussed here.