3. NPS Use among vulnerable populations in Scotland
As described in the Methods chapter, we explored the use of the multiplier method (using a treatment multiplier) to estimate the prevalence of NPS use amongst vulnerable groups in Scotland. This analysis concluded that it is not currently possible to generate a reliable estimate of overall prevalence.
As a result, this chapter focuses on estimates for one of the key target groups (injecting drug users), where data from the NEO 360 database were more robust. It also describes patterns of NPS use amongst each of the key groups, based on responses to the NPS survey, and presents the perceptions of staff in services about prevalence of NPS use amongst their clients, based on responses to the staff survey.
3.1 Quantitative survey and 'risk' groups
3.1.1 NPS and other drug use amongst NPS survey respondents
As described above, the NPS survey was completed by 424 people, 59% (n=251) in treatment or service settings and 41% (n=173) online. 
- 59% (n=252) of respondents reported having ever taken NPS. 74% (n=184) of those who had taken NPS reported use in the last six months.
- The majority of those using NPS in the last six months reported having taken synthetic cannabinoids (41%, n=104) and benzo-type NPS (41%, n=102), while approximately one fifth reported taking stimulant-type NPS (21%, n=53) and mephedrone (19%, n=48).
- Poly-substance use was very high. Only one person reported being a sole NPS user, with 99% (n=251) of NPS users also reporting traditional drug use.
- 86% (n=364) of all respondents to the NPS survey reported ever using traditional illicit drugs. Use of illicit substances within the last 6 months included: cannabis (40%, n=148), benzodiazepines (29%, n=105), heroin (23%, n=83) and powder cocaine (13%, n=46).
Traditional drug use within the last month amongst NPS users is laid out in Figure 3.1 overleaf. Over half had used cannabis (57%, n=143), two fifths had used benzodiazepines (41%, n=103) and almost a third (32%, n=82) had used heroin within the last month.
Figure 3.1. Last month traditional drug use among NPS users
Base: 252 respondents who reported ever taking NPS
3.1.2 Routes of Administration
Preferred route of administration varied by substance (detailed in figure 3.2). For people who had used NPS in the last 6 months:
- Of the 93 people who answered the question on routes of administration for synthetic cannabinoids, 91 respondents (98%) reported smoking.
- Of the 87 people who answered the question onroutes of administration for benzodiazepine-type NPS, 57 respondents (66%) reported taking it orally and 24 respondents (28%) reported taking it sublingually.
Both stimulant-type NPS and mephedrone were taken in more diverse ways:
- Of the 49 people who answered the question onroutes of administration for stimulant-type NPS, 25 respondents (51%) reported snorting and 16 respondents (33%) reported injecting. Smaller numbers reported swallowing and smoking.
- Of the 44 people who answered the question on routes of administration for mephedrone, 26 respondents (59%) reported snorting and 12 respondents (27%) reported injecting. Smaller numbers reporting swallowing and smoking.
Fig 3.2: Reported NPS use and preferred route of administration 
Base  : (synthetic cannabinoid users n=93, benzodiazepine-type NPS n=87, stimulant-type NPS n=49, mephedrone n=44)
3.2 People who inject drugs
Based on the analysis of needle exchange data for NHS GGC and NHS Lothian, we estimate that there are 190 (confidence interval 114-265)  injecting NPS users in NHS GGC and a further 673 (confidence interval 562-784)  NPS injectors in the NHS Lothian area  .
The NPS survey provides information on 141 people who inject drugs. The levels of NPS use recorded were high. 96% (n=136) of this group reported ever using NPS. The most frequently reported NPS used by this group in the last six months were:
- Benzodiazepine-type NPS (58%, n=82), and
- Synthetic cannabnoids (68%, n=48).
Amongst all PWID, 33% (n=47) reported injecting NPS in the last six months. This was almost exclusively stimulant-type NPS including mephedrone, ethylphenidate and cocaine-type NPS:
- Of the 30 injecting NPS users who had used mephedrone in the last six months, half (n=15) had injected it
- Of the 33 injecting NPS users who had used cocaine-type NPS in the last six months, nearly two thirds (n=20) had injected it
- Of the 14 injecting NPS users who had used ethylphenidate in the last six months, 12 had injected it.
Nine people reported currently injecting NPS. For those that did, the average frequency for injecting was 5 times per day and people reported incidences of equipment sharing and poor injecting technique such as not filtering  ,'missed hits'  or using citric acid  which is not required for the majority of NPS.
PWID were most likely to source NPS from:
- Shops (48% n=67)
- Dealer (47%, n=66)
- Friends or family (34%, n=47)
Small numbers of PWID sourced online (8% n=11) or selected 'other' (5%, n=7). Some respondents sourced from multiple sources.
3.3 Mental health service users
The NPS survey gained information from 99 people currently in contact with mental health services. It found that 95% (n=94) of respondents to the survey, who were currently in contact with mental health services, had ever used NPS. The most frequently reported NPS used by this group in the last six months were:
- Synthetic cannabinoids (55%, n=52)
- Benzodiazepine-type NPS (49%, n=46)
- Stimulant-type NPS (not including ethylphenidate) (31%, n=29), and
- Mephedrone (22%, n=21)
All respondents used NPS with other drugs.
Mental health service users sourced NPS from:
- Shops (47%, n=44)
- Dealer (40%, n=38)
- Friends or family (35%, n=33)
Small numbers reported sourcing online (11%, n=10) or selected 'other' (6%, n=6). Some respondents sourced from multiple sources.
3.4 Vulnerable young people
The NPS survey gained information from 69 vulnerable young people. It found that 56% (n=39) of vulnerable young people who responded to the survey had ever used NPS. The most frequently reported NPS used by this group in the last six months were:
- Synthetic cannabinoids (48%, n=19)
- Benzodiazepine-type NPS (31%, n=12)
- Mephedrone (23%, n=9), and
- Stimulant-type NPS (not including ethylphenidate) (21%, n=8)
One respondent reported using NPS only, with the rest combining NPS use with traditional drugs.
Vulnerable young people sourced NPS from:
- Shops (51%, n=20)
- Friends or family (31%, n=12)
- Dealer (26%, n=10)
Small numbers reported sourcing online (15%, n=6) or selected 'other' (5%, n=2). Some respondents sourced from multiple sources.
3.5 Homeless people
The NPS survey gained information from 92 people currently affected by homelessness, this included people in homelessness projects and rough sleepers. It found that 87% (n=76) had ever used NPS. The most frequently reported NPS used by this group in the last six months were:
- Synthetic cannabinoids (63%, n=48)
- Benzodiazepine-type NPS (59%, n=45)
- Stimulant-type NPS (not including ethylphenidate) (21%, n=16), and
- Mephedrone (17%, n=13)
All respondents used NPS with other drugs.
People affected by homelessness sourced NPS from:
- Dealer (54%, n=41)
- Shops (49%, n=37)
- Friends or family (35%, n=27)
Small numbers reported sourcing online (7%, n=5) or selected 'other' (4%, n=3). Some respondents sourced from multiple sources.
3.6 Men that have sex with men ( MSM)
The NPS survey gained information from 70 men who identified as MSM. It found that 54% (n=38) had ever used NPS. The most frequently reported NPS used by this group in the last six months were:
- Mephedrone (37%, n=14), and
- GHB/ GBL (32%, n=12)
There were small numbers using other types of NPS including benzodiaepine-type NPS (13%, n=5) and synthetic cannabinoids (10%, n=4). All respondents used NPS with other drugs.
From the 30 MSM who answered where they sourced NPS from, respondents said they got NPS from:
- Dealers (43%, n=13)
- Shops (43%, n=13)
- Friends or family (40%, n=12)
Small numbers reported sourcing online (7%, n=2) or selected 'other' (7%, n=2). Some respondents sourced from multiple sources.
3.7 Service Provider Survey Results
The staff survey addressed staff perceptions of prevalence and trends in presentation. The majority of staff surveyed were from Tayside (21%, n=38), Lothian (20%, n=37) and Greater Glasgow & Clyde ( GGC) (17%, n=32) NHS regions. The majority worked with people with mental health issues (84%, n=154), homeless people (74%, n=136) and PWID (72%, n=132). 70% (n=128) worked in drug and alcohol support services.
3.7.1 Service Provider Perception of Client Drug Use
In most services, staff perceived that the bulk of clients took only traditional drugs, with 65% (n=114) of staff perceiving that more than half of their clients only used traditional drugs. In comparison to this, 84% (n=101) of staff responding to this survey felt that less than a quarter of their clients only used NPS. 12%  (n=19) of staff thought that more than half of their clients used both traditional drugs and NPS. Further detail is laid out in Figure 3.3.
Fig. 3.3: Staff perception of client drug use by percentage of client group presenting for NPS, traditional drugs or both
Base  (respondents to question on only traditional drug use n=175, only NPS n=120, both traditional drugs & NPS n=158)
3.7.2 Staff Perceptions of Client Presentation over Time
When asked about how patterns of presentation in relation to NPS use and traditional drug use had changed over the previous six months, overall staff felt that things had remained largely the same. This is described in Fig. 3.4 overleaf.
- Fewer staff (18%, n=33) felt that they had seen a decrease in ' NPS only' presentations since autumn 2015, compared to those that had seen an increase (25%, n=46) in NPS only presentations.
- A lower proportion of staff (14%, n=26) felt that they had seen a decrease in combined NPS and traditional drug presentations since autumn 2015 than had seen an increase (26%, n=47).
This suggests that trends are not consistent across all regions and all services, but that there has potentially been a slight upward trend in presentations related to NPS use to services since the autumn of 2015.
Fig. 3.4: Staff Perception on Patterns of Presentation: Spring 2016 compared to Autumn 2015
Service providers were also asked which NPS were of particular concern. 57% of staff reported concern about benzodiazepine-type NPS, and 53% reported concern about mephedrone use. All NPS that cause staff concern are described in Table 3.2.
Table 3.2: NPS staff worry about
|None of the above||20||11|
The prevalence of NPS use among vulnerable populations in Scotland remains a challenge to measure. The under reporting of NPS use by vulnerable populations to services highlighted in the survey combined with limited existing data within services and availability of national data sets meant that developing a complete estimate of prevalence was not possible.
Nonetheless, this chapter has begun to develop our knowledge of patterns of NPS use amongst key vulnerable groups in Scotland. Of those completing the NPS survey, over half reported having ever used NPS, although the last six month use rate was lower. This could suggest a downward trend in NPS use, or a high rate of NPS experimentation compared to continued use. Staff perceptions of trends were of an overall slight upward trend in NPS-related presentation, although these varied geographically and by type of service.