Assessment of clinical outcomes of medicinal cannabis therapy for depression: analysis from the UK Medical Cannabis Registry

Figures & data

Table 1. Baseline data about patient demographics and medical history (n = 129).

Demographic details	n (%)/mean ± SD
Sex
Male	95	(73.6%)
Female	34	(26.4%)
Age (years)	35.6 ± 11.1
Occupation
Armed forces occupations	1	(0.8%)
Clerical support workers	4	(3.1%)
Craft and related trades workers	5	(3.9%)
Elementary occupations	19	(14.7%)
Managers	7	(2.3%)
Professional	11	(8.5%)
Service and sales workers	6	(4.7%)
Skilled agricultural, forestry and fishery workers	1	(0.8%)
Technicians and associate professionals	11	(8.5%)
Other occupations	10	(7.8%)
Unemployed	34	(26.4%)
Unspecified	20	(15.5%)
BMI (kg/m^2)	26.9 ± 6.3
Medical history	n (%)/median (IQR)
Smoking status
Never smoked	29	(22.5%)
Ex-smoker	40	(31.0%)
Current smoker	60	(46.5%)
Smoking pack years (current or ex-smokers)	10.0 (4.0–20.0)
Weekly units of alcohol consumption	1.0 (0.0–6.0)
Recreational cannabis use
Never used	12	(10.9%)
Ex-user	27	(20.9%)
Current user	88	(68.2%)
Cannabis gram years (current or ex-users)	6.5 (2.0–20.0)
Current antidepressant medication
Amitriptyline	3	(2.3%)
Citalopram	14	(10.9%)
Duloxetine	2	(1.6%)
Escitalopram	1	(0.8%)
Fluoxetine	5	(3.9%)
Fluvoxamine	1	(0.8%)
Lofepramine	2	(1.6%)
Mirtazapine	11	(8.5%)
Paroxetine	1	(0.8%)
Reboxetine	1	(0.8%)
Sertraline	21	(16.3%)
Trazodone	2	(1.6%)
Venlafaxine	19	(14.7%)
Not currently on antidepressants	57	(44.2%)

Table 2. Primary, secondary, and tertiary indications for cannabis-based medicinal products of study participants (n = 129).

Indication	Primary n (%)	Secondary n (%)	Tertiary n (%)
Depression	129 (100%)	-	-
Anxiety	-	42 (32.6%)	4 (3.1%)
Attention deficit hyperactivity disorder	-	4 (3.1%)	0 (0.0%)
Autism spectrum disorder	-	1 (0.8%)	3 (2.3%)
Chronic pain	-	3 (2.3%)	4 (3.1%)
Eating disorder	-	1 (0.8%)	0 (0.0%)
Insomnia	-	3 (2.3%)	8 (6.2%)
Migraine	-	1 (0.8%)	1 (0.8%)
Obsessive compulsive disorder	-	0 (0.0%)	1 (0.8%)
Post-traumatic stress disorder	-	2 (1.6%)	2 (1.6%)

Table 3. Median (IQR) baseline and follow-up scores for PHQ-9, GAD-7, SQS, EQ-5D-5L, and PGIC at 1, 3, and 6 months.

		n	Baseline Score	Follow-Up Score	T	z-score	p-value
PHQ-9	1 month	103	15.00 (9.00–21.00)	8.00 (4.00–14.00)	645.00	−6.39	<0.001
	3 months	68	15.50 (7.00–25.00)	7.00 (2.25–12.75)	214.50	−5.70	<0.001
	6 months	33	12.00 (5.00–20.50)	7.00 (2.00–9.50)	78.50	−3.33	<0.001
GAD-7	1 month	107	12.00 (7.00–18.00)	6.00 (3.00–11.00)	643.00	−6.63	<0.001
	3 months	72	11.00 (6.25–16.75)	5.00 (2.00–9.00)	138.50	−6.03	<0.001
	6 months	34	9.50 (4.75–14.50)	5.50 (2.75–9.00)	155.00	−2.44	0.015
SQS	1 month	107	4.00 (2.00–6.00)	6.00 (4.00–8.00)	3446.50	5.94	<0.001
	3 months	71	4.00 (2.00–6.00)	7.00 (4.00–8.00)	1834.00	5.34	<0.001
	6 months	33	5.00 (3.00–7.00)	6.00 (4.00–8.00)	261.00	2.19	0.029
EQ-5D-5L Mobility	1 month	107	1.00 (1.00–2.00)	1.00 (1.00–2.00)	117.00	−2.92	0.003
	3 months	71	1.00 (1.00–2.00)	1.00 (1.00–1.00)	30.50	−2.54	0.011
	6 months	33	1.00 (1.00–1.50)	1.00 (1.00–1.00)	8.00	−1.13	0.257
EQ-5D-5L Self-Care	1 month	107	1.00 (1.00–2.00)	1.00 (1.00–2.00)	132.00	−2.62	0.009
	3 months	71	1.00 (1.00–2.00)	1.00 (1.00–1.00)	71.00	−2.40	0.016
	6 months	33	1.00 (1.00–2.00)	1.00 (1.00–2.00)	22.50	−0.54	0.589
EQ-5D-5L Usual Activities	1 month	107	3.00 (2.00–3.00)	2.00 (1.00–2.00)	290.00	−5.72	<0.001
	3 months	71	2.00 (2.00–3.00)	1.00 (1.00–2.00)	70.00	−5.03	<0.001
	6 months	33	2.00 (2.00–3.00)	2.00 (1.00–2.00)	37.00	−2.82	0.005
EQ-5D-5L Pain and Discomfort	1 month	107	2.00 (1.00–3.00)	1.00 (1.00–2.00)	329.00	−4.47	<0.001
	3 months	71	2.00 (1.00–3.00)	1.00 (1.00–2.00)	70.00	−4.53	<0.001
	6 months	33	2.00 (1.00–2.00)	1.00 (1.00–2.00)	28.00	−1.70	0.090
EQ-5D-5L Anxiety and Depression	1 month	107	3.00 (2.00–4.00)	3.00 (2.00–3.00)	307.50	−6.20	<0.001
	3 months	71	3.00 (3.00–4.00)	2.00 (2.00–3.00)	162.50	−4.83	<0.001
	6 months	33	3.00 (2.00–4.00)	2.00 (2.00–3.00)	41.00	−3.35	<0.001
EQ-5D-5L Index Value	1 month	107	0.54 (0.31–0.74)	0.74 (0.61–0.85)	4453.50	6.36	<0.001
	3 months	71	0.55 (0.33–0.74)	0.77 (0.63–0.88)	1984.50	5.62	<0.001
	6 months	33	0.65 (0.43–0.81)	0.75 (0.66–0.88)	353.50	2.94	0.003
PGIC	1 month	106	-	6.00 (5.00–6.00)	-	-	-
	3 months	71	-	6.00 (5.00–6.00)	-	-	-
	6 months	34	-	6.00 (6.00–6.00)	-	-	-

Figure 1. Box plots showing the change in PHQ-9 from baseline at 1, 3, and 6 months. Wilcoxon signed-rank tests were used for comparison between time intervals, *p < 0.050.

Table 4. Subgroup analysis of median (IQR) changes in PHQ-9 from baseline at 1, 3, and 6 months. Subgroups were compared using Mann-Whitney U tests.

	1 month			3 months			6 months
	n	Median (IQR)	p-value	n	Median (IQR)	p-value	n	Median (IQR)	p-value
Baseline anxiety
GAD-7 < 5	11	−1.0 (−2.0, 4.0)	0.002	9	−2.0 (−3.0, 0.5)	0.010	8	−2.0 (−3.8, −1.0)	0.190
GAD-7 ≥ 5	92	−6.0 (−10.0, −1.0)		59	−7.0 (−12.0, −2.0)		25	−9.0 (−14.0, 1.0)
Cannabis status
Cannabis naïve	10	0.5 (−4.5, 2.3)	0.017	4	3.0 (0.0, 3.0)	0.002	4	1.0 (−1.8, 5.3)	0.041
Current or ex-user	93	−5.0 (−10.0, −1.0)		64	−6.0 (−11.0, −2.0)		29	−6.0 (−14.0, −0.5)
Baseline depression severity
Mild-moderate	71	−2.0 (−7.0, 1.0)	<0.001	49	−3.0 (−9.0, 0.5)	<0.001	23	−2.0 (−6.0, 2.0)	<0.001
Severe	32	−8.5 (−17.0, −3.3)		19	−11.0 (−18.0, −6.0)		10	−14.5 (−19.0, −12.0)
Antidepressant medication
Not prescribed	44	−3.0 (−10.0, −0.3)	0.883	33	−5.0 (−12.0, −2.0)	0.347	19	−5.0 (−12.0, 0.0)	0.529
Currently prescribed	59	−5.0 (−9.0, −1.0)		35	−5.0 (−9.0, 0.0)		14	−3.5 (−15.3, −0.3)

Table 5. Adverse events recorded by participants (n = 129).

Adverse event	Mild	Moderate	Severe	Total (%)
Agitation	0	1	0	1	(0.8%)
Amnesia	3	1	0	4	(3.1%)
Anorexia	1	2	0	3	(2.3%)
Anxiety	0	3	0	3	(2.3%)
Ataxia	3	0	0	3	(2.3%)
Blurred vision	1	0	0	1	(0.8%)
Cognitive disturbance	4	2	1	7	(5.4%)
Concentration impairment	8	2	2	12	(9.3%)
Confusion	1	2	0	3	(2.3%)
Constipation	4	2	1	7	(5.4%)
Delirium	2	1	0	3	(2.3%)
Depression	0	1	1	2	(1.6%)
Diarrhea	0	0	3	3	(2.3%)
Dizziness	3	2	0	5	(3.9%)
Dry mouth	10	2	0	12	(9.3%)
Dysgeusia	2	0	0	2	(1.6%)
Dyspepsia	1	0	0	1	(0.8%)
Fatigue	5	7	2	14	(10.9%)
Headache	7	3	1	11	(8.5%)
Increased appetite	1	0	0	1	(0.8%)
Insomnia	3	3	7	13	(10.1%)
Lethargy	5	6	0	11	(8.5%)
Muscular weakness	1	0	0	1	(0.8%)
Nausea	3	4	0	7	(5.4%)
Psychosis	0	0	1	1	(0.8%)
Pyrexia	1	0	0	1	(0.8%)
Rash	0	1	0	1	(0.8%)
Respiratory infection	0	2	0	2	(1.6%)
Somnolence	0	7	0	7	(5.4%)
Suicidal ideation	0	0	1	1	(0.8%)
Tremor	0	1	0	1	(0.8%)
Upper abdominal pain	2	0	0	2	(1.6%)
Vertigo	1	1	0	2	(1.6%)
Vomiting	2	1	0	3	(2.3%)
Weight loss	2	0	0	2	(1.6%)
Total (%)	76 (58.9%)	57 (44.2%)	20 (15.5%)	153	(118.6%)