1. To use or not to use?
An exploration of cannabis use motives and constraints
Dr Liz Temple

2. Why this topic? Changes in legal status of cannabis use
Decriminalisation/legalisation (medicinal vs. recreational)
Increased availability of cannabis and cannabis products
Possible impacts of increased access
Increased use by current users?
Increased number of users?
Earlier initiation of use?
More problematic use?
Depends on why people choose to use or not use

3. Three studies Study 1: Initiation of cannabis use
Study 2: Motives for current cannabis use
Study 3: Constraints on cannabis use

4. Study 1 Initiation of cannabis use
Methodology
anonymous online questionnaires
recruitment through online forums, social media, university student samples
Participants
945 adults (63% male)
18-73 years (M=29.6; SD = 11.7)
used cannabis at least once in their life
Context of first cannabis use
mean age at first use: 16 years (SD = 3.09)
85% used with friend/s; sibling (4%), boy/girlfriend (4%)
at friend’s home (35%), public space (21%), or in own home (18%)

5. Access vs. Interest Prior to Initiation of Use
All
(N = 870)
Age at first use
Subsequent daily use
<16 yrs
(N = 415)
16+ yrs
(N = 455)
Yes
(N = 564) No
(N = 216)
No Access
59 %
No interest
26 %
27 %
28 %
Concerned
6 %
5 %
7 % 
7 %
Wanted to
32 %
22 %
29 %
21 %
Access
16 %
19 %
4 %
12 %
No knowledge
11 %
13 %
9 %
Age at 1st use: 2(6, N=870) = 24.4, p <.001
Daily Use: 2(6, N=870) = 17.6, p =.007

6. Motives/Affect Associated with Initiation of Use
All
(N = 945)
Age at first use
Subsequent daily use
<16 yrs
(N = 415)
16+ yrs
(N = 455)
Yes
(N = 564) No
(N = 216)
Planned 1st use
58 %
57 %
59 %
61 %
52 %
 Motive/Affect
Curious
79 %
80 %
78 %
77 %
Excited
49 %
51 %
48 %
53 %
40 %
Happy
30 %
32 %
27 %
33 %
21 %
Unsure
22 %
Worried
13 %
12 %
14 %
Pressured
4 %
5 %
3 %
6 %
Planned 1st use: 2(1, N=870) = 6.0, p =.015
Excited: 2(1, N=870) = 13.9, p <.001
Happy: 2(1, N=870) = 14.7, p <.001

7. Study 1 Key Findings Access vs. Interest Prior to Initiation of Use
Lack of access (obviously) delays initiation of cannabis use
But, lack of interest in using is a stronger preventative
Concern about negative effects is not a particularly strong preventative (& may backfire)
Motives/Affect associated with Initiation of Use
Curiosity is the primary motivation for initial use
No differences associated with being younger/older at initiation
Planned initiation, being excited and happy about use are associated with subsequent daily use

8. Study 2 Motives for cannabis use
Methodology
anonymous online questionnaires
recruitment through online forums, social media, university student samples
Participants
978 adults (60% male)
aged (M=28.9; SD = 10.9)
had used cannabis within the previous 12 months
Cannabis use
mean age at first use: 16 years (SD = 3.39)
34 % use daily/most days; 22% weekly; 18% monthly; 26% < monthly
17% dependent (Severity of Dependence Scale)

9. Main Reason for Use All (N = 904) Daily/near daily use Dependent YesNo
(N = 588)
(N = 159)
(N = 740)
To relax
33 %
34 %
29 %
35 %
To socialise
14 % 
6 %
18 %
15 %
9 % 
To have fun
27 %
36 %
Relieve pain
9 %
10 %
Relieve distress
5 %
3 %
12 %
4 %
Help sleep
11 %
Daily/near daily use Dependent
To relax: ns ns
To socialise: 2(1, N=904) = 23.4, p <.001 ns
To have fun: 2(1, N=904) = 8.7, p =.003 ns
Relieve pain: 2(1, N=904) = 21.9, p <.001 ns
Relieve distress: 2(1, N=904) = 13.2, p <.001 2(1, N=904) = 17.6, p <.001
Help sleep: 2(1, N=904) = 14.8, p <.001 2(1, N=904) = 8.5, p =.003

10. Demographic & patterns of use differences
% Male
Age
(M & SD)
Age 1st use
% Use alone
Usual level intoxication
To relax
63 %
31 (11.2)
16.3
39 %
2.2 (1.0)
To socialise
56 % 
26 (8.8)
16.7
16 %
2.3 (1.0)
To have fun
73 %
27 (10.8)
15.8
33 %
2.6 (1.1)
Relieve pain
53 %
36 (12.9)
16.2
66 %
2.0 (1.2)
Relieve distress
41 %
28 (9.5)
15.4
64 %
2.1 (1.0)
Help sleep
40 %
27 (9.0)
15.6
43 %
2.7 (1.2)
Daily/near daily
62 %
31 (11.3)
56 %
2.4 (1.2)
Dependent
55 %
27 (8.6)
52 %
2.7 (1.1)
Reasons for Use Daily/near daily Dependent
% Male: p < ns ns
Age: p < p <.001 p =.015
Age 1st Use: ns p < p =.019
Use alone: p < p < p <.001
Intoxication: p < ns p <.001

11. Study 2 Key Findings Reasons for Use
Most common reasons given for use are to relax or have fun
Daily/near daily users differ from less frequent users on most reasons for use
Dependent users more likely to use to relieve psychological distress and help sleep than non-dependent users, but otherwise similar
Differences associated with Reasons for Use
To relax: older, more male, lower intoxication, sometimes use alone
To socialise: youngest, mod intoxication, rarely use alone
To have fun: younger, mostly male, higher intoxication, sometimes use alone
Relieve pain: oldest, lower intoxication, mostly use alone
Relieve distress: more female, lower intoxication, mostly use alone
Help sleep: younger, more female, higher intoxication

12. Study 3 Constraints on cannabis use
Methodology
anonymous online questionnaires
recruitment through online forums, social media, university student samples
Participants
451 adults (69% female)
aged (M=34.3; SD = 12.9)
General population (i.e., users & non-users)
Cannabis use
38% had never used cannabis, 28% had used, but not in past 12 months, 34% were current users
mean age at first use: 17 years (SD = 4.4)
31 % of current users use daily/most days & 19% dependent (Severity of Dependence Scale)

13. Constraints on cannabis use
Based on Richard Hammersley’s Constraint Theory
Hammersley, R. (2014). Constraint theory: A cognitive, motivational theory of dependence, Addiction Research & Theory, 22(1)
Morals: 8 items; α = .92; “It’s against my family’s religion”
Others: 7 items; α = .91; “My family disapproves of cannabis use”
Lifestyle: 7 items; α = .92; “My schedule limits when I can use cannabis”
Social: 6 items; α = .92; “I do not know many people who use cannabis”
Effects: 5 items; α = .90; “I have experienced effects of use that were unpleasant”
Stress/Other: 10 items; α = .95; “I have found better ways to relax”
Like Effects: 5 items; α = .88; “I appreciate it more if I don’t take it all the time”
Health: 5 items; α = .86; “Smoking is bad for my health”
Dependence: 6 items; α = .90; “I do not want to become addicted to cannabis”
Legal: 5 items; α = .88; “I’m worried about getting in trouble with the law if caught”
Availability: 6 items; α = .93; “I have to travel too far to get cannabis”
Cost: 7 items; α = .92; “Cannabis is too expensive”
Self Beliefs: 6 items; α = .93; “I think it is irresponsible for me to use cannabis”

14. Never Used
(N = 146)
Past Use
(N = 121)
Current Use
(N = 148)
Significance
Morals
1.5 (1.4)
1.5 (1.0)
1.6 (0.6) ns
Others
1.3 (1.4)
1.6 (1.2)
2.1 (0.8)
<.001
Lifestyle
1.2 (1.2)
2.1 (1.4)
2.5 (0.8)
Social
0.9 (0.9)
1.5 (1.2)
Effects
0.6 (0.9)
2.0 (1.3)
2.3 (0.8)
Stress/Other
0.8 (0.8)
1.4 (0.9)
2.1 (0.7)
Like Effects
0.7 (1.0)
1.4 (1.2)
2.6 (0.9)
Health
1.4 (1.0)
2.0 (1.2)
2.2 (0.8)
Dependence
2.1 (0.9)
Legal
1.0 (1.1)
1.4 (1.1)
1.9 (0.8)
Availability
0.9 (1.0)
1.3 (1.1)
1.7 (0.7)
Cost
2.4 (0.7)
Self Beliefs
2.6 (1.2)
.001

15. Daily/near daily use
(N = 44)
Less frequent use
(N = 104)
Significance
Morals
1.6 (0.5)
1.6 (0.6) ns
Others
2.3 (0.7)
2.0 (0.9)
.012
Lifestyle
2.2 (0.7)
2.6 (1.0)
.015
Social
2.0 (0.5)
2.2 (0.8)
Effects
1.8 (0.6)
2.5 (0.8)
<.001
Stress/Other
2.4 (0.6)
2.1 (0.7)
.016
Like Effects
2.9 (0.9)
2.5 (0.9)
.004
Health
Dependence
1.9 (0.7)
Legal
1.8 (0.8)
Availability
Cost
2.4 (0.8)
Self Beliefs
2.1 (0.8)

16. Dependent
(N = 21)
Non-dependent
(N = 127)
Significance
Morals
1.7 (0.5)
1.6 (0.6) ns
Others
2.6 (0.6)
2.0 (0.8)
.002
Lifestyle
2.8 (0.6)
2.5 (1.0)
Social
2.2 (0.5)
2.1 (0.8)
Effects
2.1 (0.6)
2.3 (0.9)
Stress/Other
2.4 (0.6)
2.1 (0.7)
Like Effects
3.6 (0.7)
2.4 (0.9)
<.001
Health
2.5 (0.7)
Dependence
3.3 (0.8)
1.9 (0.7)
Legal
1.8 (0.8)
Availability
1.6 (0.4)
1.7 (0.8)
Cost
2.4 (0.8)
Self Beliefs
2.5 (0.6)

17. Study 3 Preliminary Findings
Caveats
Scale still in development
Data collection on-going
Constraints on Use
Current Users differ from Past Users and Never Used groups on most constraints
May be related to lack of applicability of some items to these groups
Constraints appear associated more with regulation of Frequency of Use than of Dependence
No differences at all on morals
Strongest constraints:
Never Used & Past Users: Self Beliefs
Less Frequent & Non-dependent Users: Lifestyle
Current, Daily/near daily & Dependent Users: Like Effects

18. Conclusions & Future Directions
Controlling access to cannabis acts to delay early initiation of use, however, individuals’ lack of interest in using is a stronger factor
how do we encourage this lack of interest?
is it linked to Self Belief constraints?
While there is some overlap, motives for use and constraints on use are more strongly associated with differences in frequency of use, than in dependence
Why is this the case?
Is this due to the strength of addiction process (e.g., habituation, withdrawal avoidance, etc.)?
Reasons for use & non-use of cannabis are complex
Environmental, social and individual factors at play
As always, more research is needed