Table 3 Reasons and reported frequencies in each included study for not starting ecstasy use, using less ecstasy, or ceasing ecstasy use.

Addiction, fear of becoming dependent

(fear of addiction^B, feeling dependent on ecstasy^C, addiction/tolerance^O, addiction^P)

0%^B

16%^C

NN^O; 36.3%^P

Availability, price, quality of ecstasy

(financial reasons, high price of ecstasy^A; financial cost^B; financial difficulties^C; knowing that a pill does not contain MDMA, monetary factors, quality factors^E; ecstasy quality... decreased, increased^F; perceived drop in ecstasy quality, money is a problem^I; money problems, MDMA quality^J; availability of ecstasy^M; money^O)

NN^A; 2%^B;

57%^C; NN, NN, NN^E; 34%, 10%^F; 34%^I; NN^M

NN, NN^A *; 34%^I; 1.4, 6.3^J *; NN^O

Changing life circumstances (moving in or out of a certain lifestyle)

(having decided not to do drugs anymore^A; changes in life circumstances^E; I'm getting older, if I was spending less time at clubs, if I was spending less time at pubs, if I was spending less time at parties^I; stopped clubbing^J; growing out of the scene^L; loss of interest^O; moving on^S)

NN^E; 12%^I; NN^L;

NN^A *; 30%, 12%, 7%^I; 5.1^J *; NN^O; 16%^S

Lack of curiosity

(uninterested in the effects, unfamiliarity with the drug and/or its effects^B)

18%, 2%^B

Decreased drug effects (e.g. tolerance) or decreased appreciation of drug effects (e.g. getting bored by effects)

(needing to take more tablets than used to^F; I'm not getting the same rush as I used to get^I; bored of the drug's effects^M)

9%^F; 18%^I; NN^M

Ecstasy is overrated

(ecstasy is boring or overrated^A; not every ecstasy experience is necessarily as good as the last^L)

NN^L

25%^A *

Experienced no effects or unpleasant effects

(experience was unpleasant, found the experience boring^A; not enjoying drug^J; intensity of first experience was overwhelming and not worth the trouble of continuing to use^K; ecstasy did nothing to me^P)

25%, 41%^A

5.6^J *; NN^K; 44%^P

Fear of ecstasy's effects

(fear of the effects^B)

43%^B

Lack of opportunity

(having had no opportunity to take ecstasy^A; lack of opportunity^B)

NN^A; 10%^B

Legal consequences

(external circumstances (legal)^E; getting a criminal record^I; criminal record^J; fear of legal consequences^O)

7%^E; 10%^I; 1.2^J *; NN^O

Minimising ecstasy comedown

(avoiding the ecstasy comedown^Q)

56%^Q

Minimising health risks or fear of health risks

(wariness regarding the effects of ecstasy, health reasons^A; fear of physical harm, fear of psychological harm^B; physical health effects, psychological problems^C; potential health risks, minimise the potential for negative or adverse outcomes^E; worrying about... dying from ecstasy use, risk of brain damage^F; fears about... long-term effects on mental health, long-term effects on physical health, short-term effects on mental health, short-term effects on physical health^I; long-term mental health, short-term mental health^J; avoid potential risks^K; health concerns^O; fear of damage to health^P; avoiding ecstasy-related negative side-effects, avoiding brain damage or neurotoxicity^Q; negative effects^S)

NN^A; 33%, 0%^B

45%, 39%^C; NN, NN^E; 15%, 25%^F; NN, NN^K; 71%, 58%^Q

NN^A *; 67%, 46%, 17%, 13%^I; 5.8, 4.5^J *; NN^O; 62%^P; 14%^S

Noticed mood/affective/cognitive changes in oneself

(external circumstances (medical)^E; feeling depressed a few days after use^F; finding it was doing my head in, it takes it out of you physically, I get depressed, I have some memory loss, it takes longer to come down, I have not been feeling healthy, it makes me less tolerant to others^I; depressed, paranoia, anxiety, memory, concentration, physical health worries, impulsive behaviour, sleeping worries, angry, eating worries^J; depression^M)

27^F; 30%, 17%, 13%, 13%, 12%, 6%^I; NN^M

7%^E; 50%^I; 5.6, 5.4, 5.3, 5.1, 4.9, 4.3, 3.3, 3.1, 3.0, 2.9^J *

Observation of others using ecstasy

(seen the effect on others^B; observation of others using ecstasy^O)

16%^B

NN^O

Other's bad experience/mood/affective/cognitive changes/death

(knowing someone who had a bad experience on ecstasy^F; seeing someone have a bad experience on MDMA, knowing someone who... died as a result of taking MDMA, became mentally ill, became physically ill^I; other's bad experience, other mentally ill^J; other's bad experiences^M)

11%^F; NN^M

31%, 19%, 17%, 14%^I; 2.9, 2.2^J *

Own bad experience

(having a bad experience on ecstasy^F; personally having a bad experience on MDMA^I; bad experience^J; own bad experience^M; problems caused by ecstasy^N; negative personal experiences^O)

22%^F; NN^M

25%^I; 3.4^J *; 60%^N; NN^O

Responsibilities (interference with or increase/decrease in) or relationship problems

(occupational problems, to improve quality of life, relationship problems^C; social factors^E; it places strains on my job/studies, I have more responsibilities, if I thought it... was negatively influencing my work/study, might affect my job^I; work affected^J; fear of reduced efficiency^P)

28%, 17%^C; NN^E; 19.6%, 11.3%^I

NN^A *; 37%^C; 18%, 16%^I; 4.7^J *; 75%^P

Social influence (friends quit using ecstasy)

(peer influence^B; if friends were giving up, most of my friends have given it up^I; friends quit^J; peer-group behaviours, being with people who don't use (many) drugs^M)

7%^B

9%^I; NN, NN^M

22%^I; 1.8^J *

Social influence from relatives

(pressure from relatives, relatives finding out I was taking MDMA^I; relatives finding out, relatives' pressure^J)

2%, 2%^I; 2.0, 1.7^J *