Table 3 Overview of all measures and their measurement time points

1

Socio-demographics (age, gender, sexual orientation, educational attainment, migration background, financial situation)

X

2

Cannabis Use Disorders Identification Test (CUDIT-R)

X

X

X

X

3

Cannabis use

3a

Consumption Patterns (Years of Use, 30-day point prevalence of cannabis and CBD abstinence, Type of Consumption)

X

X

X

X

3b

Defining the personal standard joint

X

3c

TLFB (Cannabis use frequency and amount for the last 7 days in standard joint units)

X

X

X

X

4

Severity of Dependence Scale (SDS)

X

X

X

X

5

Short version of the Alcohol Use Disorders Identification Test (AUDIT-C)

X

X

X

6

National Institute on Drug Abuse Screening (NIDA ASSIST)

X

X

X

7

Drug Abuse Screening Test (DAST-10)

X

8

Perceived Stress Scale (PSS-10)

X

X

X

X

9

Patient Health Questionnaire for Depression (PHQ-9)

X

X

X

10

Generalized Anxiety Disorder Screener (GAD-7)

X

X

X

11

Adult ADHD Self-Report Scale (ASRS-V1.1)

X

12

Mindfulness Attention Awareness Scale (MAAS)

X

X

X

X

13

Comprehensive Inventory of Mindfulness Experiences (CHIME)

X

14

Previous experience in meditation (no official instrument)

X

15

Client Satisfaction Questionnaire for Internet Interventions (CSQ-I)

X^a

16

Negative effects, according to Rozental et al. (2015)

X

17

Use of any services besides CANreduce

X

X

18

Adherence and Retention^b

X