Prevalence of Legal, Prescription, and Illegal Drugs Aiming at Cognitive Enhancement across Sociodemographic Groups in Germany

Figures & data

Table 1. Sample description without and with sampling weights (N = 22,101).

	Unweighted Frequency	Unweighted proportion (in %)	Weighted proportion (in %)
Sex
Male	12,102	54.76	51.29
Female	9,999	45.24	48.71
Age
18–24	710	3.21	7.98
25–34	2,059	9.32	17.93
35–44	3,068	13.88	16.79
45–54	4,401	19.91	17.22
55–64	5,781	26.16	21.57
65–74	4,642	21.00	14.57
75–95	1,440	6.52	3.94
Education
Secondary I and below	1,986	8.99	27.62
Secondary II	5,872	26.57	31.41
University entrance qualification	5,377	24.33	17.90
Tertiary education	8,866	40.12	23.07
Employment status
Full-time	10,247	46.36	48.27
Part-time	4,553	20.60	20.54
In education	666	3.01	6.98
Not employed	6,635	30.02	24.21
Income
Low	3,524	15.94	21.57
Medium	17,160	77.64	74.02
High	1,417	6.41	4.41
Partner living in the household
No	6,451	29.19	35.42
Yes	15,650	70.81	64.58
Place of residence
Urban	15,910	71.99	71.16
Rural	6,191	28.01	28.84
Diagnosis of mental illness
None	16,139	73.02	71.22
Still in treatment (1=yes)	2,585	11.70	13.1
No longer in treatment (1=yes)	3,377	15.28	15.67

Table 2. Prevalence of different drugs used for cognitive enhancement and respective use periods across respondent characteristics in percentages with 95% confidence intervals in square brackets (N = 22,101).

	Caffeinated drinks(twelve months)	Caffeine tablets(twelve months)	Food supplements and home remedies (twelve months)	Prescription drugs(lifetime)	Prescription drugs(twelve months)	Prescription drug use willingness	Cannabis(lifetime)	Cannabis(twelve months)	Other illegal drugs(lifetime)	Other illegal drugs(twelve months)
Total	62.4 [62.3;62.4]	2.5 [2.5;2.5]	31.4 [31.3;31.4]	5.5 [5.5;5.6]	3.7 [3.7;3.7]	40.5 [40.4;40.6]	10.7 [10.6;10.7]	4.1 [4.1;4.2]	4.1 [4.0;4.1]	1.6 [1.6;1.6]
Sex
Male	63.5 [63.4;63.6]	3.1 [3.1;3.2]	27.1 [27.0;27.2]	5.0 [4.9;5.0]	3.3 [3.2;3.3]	37.4 [37.3;37.5]	12.7 [12.6;12.7]	5.1 [5.1;5.1]	5.0 [4.9;5.0]	2.2 [2.1;2.2]
Female	61.2 [61.1;61.3]	1.8 [1.8;1.9]	35.8 [35.8;36.0]	6.1 [6.1;6.1]	4.2 [4.1;4.2]	43.8 [43.7;43.9]	8.6 [8.5;8.6]	3.1 [3.1;3.2]	3.1 [3.1;3.2]	1.1 [1.0;1.1]
Age
18–24	65.9 [65.6;66.1]	4.8 [4.7;4.9]	30.4 [30.1;30.6]	6.6 [6.5;6.8]	4.5 [4.4;4.6]	43.9 [43.7;44.1]	15.6 [15.4;15.8]	11.1 [11.0;11.3]	5.9 [5.8;6.0]	4.6 [4.5;4.7]
25–34	74.3 [74.1;74.4]	4.7 [4.6;4.7]	34.9 [34.7;35.0]	6.9 [6.8;7.0]	4.8 [4.8;4.9]	42.9 [42.8;43.1]	18.6 [18.5;18.7]	7.1 [7.0;7.2]	8.4 [8.3;8.5]	3.6 [3.6;3.7]
35–44	71.0 [70.8;71.1]	3.5 [3.5;3.6]	33.1 [32.9;33.2]	3.9 [3.8;3.9]	2.2 [2.1;2.2]	38.3 [38.2;38.5]	16.1 [15.9;16.2]	5.5 [5.5;5.6]	5.8 [5.7;5.9]	1.8 [1.7;1.8]
45–54	61.8 [61.6;62.0]	1.6 [1.6;1.7]	30.9 [30.7;31.0]	4.7 [4.7;4.8]	3.2 [3.1;3.2]	39.8 [39.7;40.0]	8.7 [8.6;8.8]	2.2 [2.2;2.2]	3.1 [3.1;3.2]	0.9 [0.9;0.9]
55–64	59.5 [59.3;59.6]	1.3 [1.3;1.3]	29.8 [29.7;30.0]	6.0 [6.0;6.1]	4.0 [4.0;4.1]	39.3 [39.1;39.4]	6.4 [6.3;6.5]	2.3 [2.2;2.3]	1.7 [1.7;1.8]	0.6 [0.6;0.6]
65–74	45.9 [45.8;46.1]	0.8 [0.7;0.8]	28.7 [28.5;28.9]	5.1 [5.0;5.1]	3.6 [3.5;3.6]	39.8 [39.6;40.0]	3.1 [3.0;3.2]	0.9 [0.9;10.0]	1.0 [1.0;1.1]	0.1 [0.1;0.1]
75–95	43.8 [43.4;44.1]	0.6 [0.6;0.7]	30.7 [30.4;31.0]	6.3 [6.1;6.5]	4.6 [4.4;4.7]	43.8 [43.4;44.1]	1.9 [1.9;2.0]	0.9 [0.8;0.9]	1.3 [1.2;1.4]	0.2 [0.2;0.3]
Education
Secondary I and below	57.1 [57.0;57.2]	1.2 [1.2;1.2]	29.4 [29.3;29.5]	6.6 [6.5;6.7]	4.3 [4.3;4.4]	43.3 [43.1;43.4]	7.0 [7.0;7.1]	3.2 [3.2;3.3]	2.6 [2.6;2.6]	1.2 [1.2;1.3]
Secondary II	63.3 [63.2;63.4]	3.0 [3.0;3.1]	31.8 [31.7;32.0]	6.1 [6.0;6.1]	4.5 [4.4;4.5]	41.0 [40.9;41.1]	10.8 [10.7;10.9]	4.2 [4.1;4.2]	4.6 [4.6;4.7]	1.8 [1.8;1.9]
University entrance qualification	66.3 [66.1;66.4]	3.8 [3.7;3.9]	33.6 [33.4;33.7]	5.2 [5.2;5.3]	3.4 [3.4;3.5]	42.3 [42.1;42.5]	14.9 [14.8;15.0]	6.4 [6.3;6.4]	5.7 [5.7;5.8]	2.5 [2.5;2.6]
Tertiary education	64.5 [64.3;64.6]	2.3 [2.3;2.3]	31.4 [31.2;31.5]	3.7 [3.7;3.8]	2.1 [2.1;2.1]	35.1 [35.0;35.2]	11.6 [11.5;11.7]	3.4 [3.4;3.5]	3.8 [3.7;3.8]	1.1 [1.1;1.2]
Employment status
Full-time	67.7 [67.6;67.8]	3.3 [3.3;3.4]	30.5 [30.4;30.6]	4.4 [4.4;4.5]	2.9 [2.9;3.0]	38.1 [38.0;38.2]	12.3 [12.3;12.4]	4.0 [3.9;4.0]	4.8 [4.8;4.9]	1.7 [1.7;1.7]
Part-time	63.0 [62.8;63.1]	2.2 [2.2;2.3]	34.9 [34.8;35.1]	6.8 [6.6;6.8]	4.5 [4.5;4.6]	41.4 [41.3;41.6]	10.8 [10.7;10.9]	4.4 [4.4;4.5]	4.6 [4.5;4.6]	2.3 [2.3;2.4]
In education	65.6 [65.4;65.8]	3.8 [3.7;3.9]	31.8 [31.5;32.0]	5.9 [5.8;6.0]	3.4 [3.3;3.5]	44.9 [44.7;45.2]	15.9 [15.7;16.1]	11.3 [11.1;11.5]	4.9 [4.8;5.0]	3.0 [2.9;3.1]
Not employed	50.3 [50.2;50.5]	0.7 [0.7;0.7]	30.0 [29.9;30.1]	6.6 [6.5;6.7]	4.6 [4.5;4.7]	43.1 [43.0;43.3]	5.8 [5.7;5.9]	2.1 [2.1;2.2]	1.9 [1.8;1.9]	0.5 [0.5;0.5]
Income
Low	65.7 [65.6;65.9]	2.9 [2.9;3.0]	33.0 [32.8;33.1]	9.3 [9.2;9.4]	6.8 [6.8;6.9]	46.7 [46.5;46.8]	13.1 [13.0;13.2]	7.0 [6.9;7.1]	5.8 [5.7;5.8]	2.7 [2.7;2.8]
Medium	61.6 [64.5;61.6]	2.4 [2.4;2.4]	30.9 [30.8;31.0]	4.5 [4.5;4.6]	2.9 [2.8;2.9]	38.9 [38.8;39.0]	10.0 [9.9;10.0]	3.3 [3.3;3.3]	3.5 [3.4;3.5]	1.2 [1.2;1.3]
High	59.6 [59.3;59.9]	2.0 [1.9;2.1]	31.3 [31.0;31.5]	3.5 [3.4;3.6]	2.4 [2.3;2.5]	36.6 [36.3;36.9]	10.9 [10.7;11.1]	4.5 [4.4;4.6]	5.8 [5.6;5.9]	2.6 [2.5;2.7]
Partner living in the household	62.4 [62.3;62.4]	2.5 [2.5;2.5]	31.4 [31.3;31.4]	5.5 [5.5;5.6]	3.7 [3.7;3.7]	40.5 [40.4;40.6]	10.7 [10.6;10.7]	4.1 [4.1;4.2]	4.1 [4.0;4.1]	1.6 [1.6;1.6]
No
Yes	63.5 [63.4;63.6]	3.1 [3.1;3.2]	27.1 [27.0;27.2]	5.0 [4.9;5.0]	3.3 [3.2;3.3]	37.4 [37.3;37.5]	12.7 [12.6;12.7]	5.1 [5.1;5.1]	5.0 [4.9;5.0]	2.2 [2.1;2.2]
Place of residence
Urban	62.7 [62.6;62.8]	2.6 [2.5;2.6]	31.6 [31.5;31.7]	5.5 [5.5;5.5]	3.6 [3.6;3.7]	40.7 [40.7;40.8]	11.4 [11.4;11.5]	4.5 [4.5;4.6]	4.6 [4.5;4.6]	1.9 [1.8;1.9]
Rural	61.6 [61.5;61.8]	2.3 [2.3;2.4]	30.8 [30.7;30.9]	5.6 [5.5;5.7]	3.9 [3.9;4.0]	39.8 [39.7;40.0]	8.9 [8.8;9.0]	3.2 [3.2;3.2]	2.8 [2.8;2.9]	1.1 [1.0;1.1]
Diagnosis of mental illness
None	60.5 [60.4;60.6]	2.1 [2.1;2.1]	27.8 [27.7;27.9]	2.7 [2.7;2.8]	1.7 [1.7;1.8]	34.7 [34.6;34.8]	8.9 [8.8;8.9]	3.1 [3.1;3.1]	2.8 [2.8;2.9]	1.0 [0.9;1.0]
Still in treatment (1 = yes)	67.1 [66.9;67.2]	4.5 [4.4;4.5]	41.3 [41.1;41.5]	15.8 [15.7;16.0]	13.0 [12.8;13.1]	57.9 [57.7;58.0]	15.6 [15.4;15.7]	6.9 [6.8;7.0]	6.8 [6.7;6.9]	3.6 [3.5;3.6]
No longer in treatment (1 = yes)	67.1 [66.9;67.3]	2.8 [2.7;2.8]	39.2 [39.0;39.4]	9.5 [9.4;9.6]	4.9 [4.9;5.0]	52.2 [52.0;52.3]	14.9 [14.8;15.1]	6.6 [6.5;6.7]	7.3 [7.2;7.5]	3.0 [3.0;3.1]

Table 3. Overlap among different use outcomes for cognitive enhancement (N = 22,101).

	1)	2)	3)	4)	5)	6)	7)	8)	9)	10)
Overlap in percent (with 95% confidence intervals in brackets)^a
1) Caffeinated drinks (twelve months)		3.8 [3.8;3.8]	39.6 [39.5;39.7]	7.1 [7.1;7.2]	4.9 [4.8;4.9]	45.4 [45.3;45.5]	13.9 [13.8;13.9]	5.7 [5.7;5.7]	5.5 [5.4;5.5]	2.2 [2.2;2.2]
2) Caffeine tablets (twelve months)	94.6 [94.4;94.8]		77.4 [77.0;77.8]	29.6 [29.2;30.0]	23.8 [23.4;24.2]	68.6 [68.2;69.0]	33.6 [33.2;34.0]	20.9 [20.5;21.2]	21.5 [21.2;21.9]	15.2 [14.8;15.5]
3) Food supplements and home remedies (twelve months)	78.8 [78.7;78.9]	6.2 [6.1;6.2]		10.6 [10.5;10.7]	7.6 [7.5;7.6]	55.2 [55.1;55.3]	14.1 [14.0;14.2]	6.3 [6.2;6.4]	6.0 [6.0;6.0]	2.7 [2.7;2.8]
4) Prescription drugs (lifetime)	80.7 [80.5;80.9]	13.4 [13.2;13.6]	60.3 [60.1;60.6]		67.1 [66.8;67.3]	77.2 [76.9;77.4]	25.7 [25.4;25.9]	16.0 [15.8;16.2]	18.2 [18.0;18.5]	11.3 [11.1;11.4]
5) Prescription drugs (twelve months)	81.9 [81.6;82.2]	16.1 [15.8;16.3]	63.9 [63.6;64.3]	100		80.9 [80.60;81.2]	25.7 [25.3;26.0]	17.9 [17.6;18.1]	18.7 [18.4;19.0]	13.9 [13.7;14.2]
6) Prescription drug use willingness	70.0 [69.9;70.0]	4.2 [4.2;4.3]	42.8 [42.7;42.9]	10.5 [10.5;10.6]	7.4 [7.3;7.5]		15.1 [15.0;15.2]	6.8 [6.7;6.8]	6.8 [6.7;6.8]	3.0 [2.9;3.0]
7) Cannabis (lifetime)	81.0 [80.8;81.1]	7.9 [7.8;8.0]	41.4 [41.2;41.6]	13.3 [13.1;13.4]	8.9 [8.8;9.0]	57.3 [57.1;57.5]		38.8 [38.5;38.9]	25.3 [25.1;25.4]	10.3 [10.2;10.6]
8) Cannabis (twelve months)	85.8 [85.6;86.0]	12.6 [12.4;12.8]	47.7 [47.4;48.0]	21.4 [21.1;21.7]	16.0 [15.8;16.2]	66.4 [66.1;66.7]	100		33.5 [33.1;33.8]	22.4 [22.1;22.7]
9) Other illegal drugs (lifetime)	84.0 [83.8;84.3]	13.2 [13.0;13.5]	46.1 [45.8;46.4]	24.8 [24.5;25.1]	17.0 [16.8;17.3]	67.1 [66.9;67.5]	66.4 [66.0;66.7]	34.1 [33.7;34.4]		40.0 [39.7;40.3]
10) Other illegal drugs (twelve months)	85.2 [84.8;85.6]	23.3 [22.8;23.8]	52.5 [52.0;53.0]	38.2 [37.7;38.7]	31.7 [31.2;32.2]	74.0 [73.5;74.4]	67.9 [67.4;68.4]	57.1 [56.6;57.6]	100
Pairwise correlations^b
1) Caffeinated drinks (twelve months)
2) Caffeine tablets (twelve months)	.11
3) Food supplements and home remedies (twelve months)	.23	.16
4) Prescription drugs (lifetime)	.09	.17	.15
5) Prescription drugs (twelve months)	.08	.17	.14	.81
6) Prescription drug use willingness	.13	.09	.20	.18	.16
7) Cannabis (lifetime)	.13	.12	.08	.12	.10	.12
8) Cannabis (twelve months)	.10	.13	.07	.14	.14	.11	.60
9) Other illegal drugs (lifetime)	.09	.14	.07	.17	.17	.11	.37	.31
10) Other illegal drugs (twelve months)	.06	.17	.06	.18	.18	.09	.24	.34	.62

Notes: ^aNumbers represent the proportion of people to whom both the row information and column information apply (e.g., the number in the first row and the second column indicates that 3.8% of those who reported consuming caffeinated drinks also reported consuming caffeinated tablets). ^bPearson’s coefficients are presented.

Figure 1. Twelve-month prevalence and respective frequencies of using legal drugs for cognitive enhancement in percentages (N = 22,101).

Figure 2. Past twelve months (

) and prior to the past twelve months (□) prevalence and respective frequencies of using prescription drugs for cognitive enhancement. Notes: ^anot all respondents provided substance names; thus, the number of users reflected in the graph is lower than that in the general prevalence information. ^binformation of analgesics and sedatives was generated from open answers.

Figure 3. Past twelve months (

) and prior to the past twelve months (□) prevalence and respective frequencies of using illegal substances for cognitive enhancement (N = 22,101).

Figure 4. Coefficient plots of twelve-month use of legal drugs for cognitive enhancement (N=22,101). Notes:

unadjusted estimates;

adjusted estimates.

Figure 5. Coefficient plots of prescription drug use for cognitive enhancement (N=22,101). Notes:

unadjusted estimates;

adjusted estimates.

Figure 6. Coefficient plots of illegal drug use for cognitive enhancement (N=22,101). Notes:

unadjusted estimates;

adjusted estimates.