3.5 PRUEBAS DE LABORATORIO
3.5.3 PRUEBAS ESPECIALES
3.5.3.2 Prueba de Taponamiento de Permeabilidad (P.P.T)
The majority o f participants were recruited in London (68%), and the other 32% in Manchester. Approximately half o f the participants were employed in full-time work (48%), 15% worked part-time, 23% were students and 13% were unemployed. Data from 34 users were discarded because none o f these participants completed the interview beyond question number 7. Two respondents were excluded as they were not regular users o f MDMA (i.e. consumed at least once every two months). The resulting 430 participants (238 male, 192 female) had an age range o f 17-36 years (mean 24.40, ± 3.72). There was a significant gender difference in age whereby men (mean 24.92 ± 3.86 years), were roughly one year older than women (mean 23.72 ± 3.44 years), [t422=3.34, p<0.001].
Patterns o f MDMA use
The interview produced data on the demographics o f drug use. These included measures o f frequency o f use when participants first started using and current frequency of use; typical amount taken in a single session when first started using and currently; and a measure o f the length o f time over which MDMA had been taken. Given that there was data concerning both initial and current drug use, it was also possible to look at changing patterns o f use over time (Table 2.1).
Average length o f consumption was 5.2 years (range =1-12 years). Males had been using MDMA for longer than females [t423=2.12, p<0.05]. Pearson product-moment correlations were carried out in order to investigate whether length o f MDMA use was connected with users’ age. Not surprisingly, age was found to be significantly correlated with years o f MDMA use in both male [r=0.65, p<0.001] and female [r=0.57, p<0.001] participants.
Table 2.1 Table o f means (s.d.) showing patterns o f MDMA use
Variable measuring MDMA use Total Mean Men Women
Length o f consumption
(years) 5.17(2.08) 5.35 (2.13) 4.93 (1.98)
Frequency o f consumption when first
Started using (days/month) ^ 2.79 (3.03) 2.94 (2.97) 2.60 (3.11) Current frequency o f consumption^
(days/month) 1.85 (3.03) 1.95 (3.41) 1.74 (2.49)
Change in frequency o f consumption
(Initial-» current use) ^ -0.86 (3.50) -0.95 (4.01) -0.76 (2.76) Amount consumed when first
Started using (no. tablets) 1.21 (0.85) 1.20 (0.79) 1.22 (0.92) Current amount consumed
(no. tablets) 1.78(1.10) 1.82(1.07) 1.73(1.13)
Change in amount consumed
(InitiaMcurrent use) (no. tablets) 0.60(1.17) 0.63 (1.27) 0.54(1.04)
The flill coding schem e for the explanation o f frequency data is presented in Table 2.2.
The frequency o f MDMA consumption data was converted from its original ranked values (see first column in Table 2.2) to give a measure o f number o f days on which MDMA was consumed per month. A 30 day month was assumed so that if a participant reported consuming MDMA on a daily basis, they were given a score o f 30; if they consumed 2-3 times a week they scored 12, and so on. When participants first started using they took MDMA on average 2-3 days/month. This fell to 1.85 days/month at the time o f interview. Conversely, the amount o f MDMA consumed in a typical session had increased from an initial average o f 1.2 tablets to 1.8 tablets currently.
Table 2.2 Coding scheme for frequency measures.
Frequency of Consumption Original Ranked Value New Value
Every day 1 30
2-3 times a week 2 12
Once a week 3 4
Once a fortnight 4 2
Once every three weeks 5 1.4
Once a month 6 1
Once every couple o f months 7 0.5
Figures 2.1a and 2.1b illustrate that whereas users take MDMA less frequently currently compared to when they first started, they tend to use a greater quantity in one session. These differences were verified statistically using the Wilcoxon matched- pairs signed-ranks test (as the data was not normally distributed). The increase in amount used over sessions was highly significant [z =12.52, p <0.001], as was the reduction in fi-equency of use [z =9.60, p < 0.001].
Users themselves confirmed this decline in frequency o f MDMA use (Table 2.3). When asked directly whether they were currently taking MDMA more or less often than when they first started using, 64% reported that they were using less frequently compared to 20% who thought they were using more frequently. There were no significant differences between male and female participants in terms o f changes in frequency o f use over time.
Table 2.3. Number o f participants reporting changes in frequency o f MDMA consumption since they first started using.
Change in frequency of use N um ber of participants (% of sample)
Have not changed use patterns 62 (15.4%)
Currently using more frequently 82 (20.3%)
F igure 2.1a. A com parison o f frequency o f M D M A use w hen participants first started using and currently
Frequency w hen first started F requency currently 45 40 - 35 - 30 - (U c oc « 25 - CC CL C * 5 t 20 - « a 10 - F requency o f use
F igu re 2.1b. A m ount o f M D M A used by particip an ts w hen they first started and currently
Amount used when first started Amount used currently
60 - 50 - « C
s
20 - 10 - 1/4 1/2 1 ta b let 1-2 3 -4 5-6 6 + ta b le t ta b let ta b lets ta b lets ta b le ts ta b letsUse o f other Drugs
The most common drugs used other than MDMA when participants first started using were tobacco (80.1%), amphetamine (speed; 55.0%) and cannabis (53.1%). Only 3 o f the 422 participants (0.7%) initially never used any other drug conjointly with MDMA.
The overall pattern of drugs mixed with MDMA did not change fi'om initial to present consumption with tobacco, amphetamine and cannabis remaining the most jfrequently used (Table 2.4). When asked about how often participants combined current MDMA use with other drugs (including tobacco and alcohol), 59% o f participants reported always mixing MDMA with another drug.
Table 2.4. A comparison o f other drugs used conjointly with MDMA when participants first started using and currently.
Drugs used % of participants using % of participants using drug when first started drug currently (n=408)
Tobacco 80.1 77.2 Amphetamine 55.0 57.4 Cannabis 53.1 52.9 Alcohol 44.3 44.1 Acid 27.3 24.5 Cocaine 22.0 21.8 Temazepam 17.8 19.1 None 0.7 1.5
Particular combinations of drugs currently mixed with MDMA were examined in order to establish whether there was a certain group o f users who mixed with a wide cocktail o f drugs and others who only used one other drug in combination with M D M \ (Table 2.5). The average number o f drugs used in combination with MDMA was 3 (not including MDMA itself), with 79.8% o f participants using either 2, 3 or 4 other drugs.
Table 2.5. Number o f ‘other’ drugs taken in combination with MDMA.
Number of ‘other’ drugs used currently
(including alcohol and tobacco)
Percentage of participants using this combination (n=408)
0 (never mix) 1.5 1 other drug 6.9 2 other drugs 28.9 3 other drugs 32.8 4 other drugs 18.1 5 other drugs 9.8 6 other drugs 1.5 7 other drugs 0.5