Diagnosis, treatment, and burden of illness among adults with attention-deficit/hyperactivity disorder in Europe

Figures & data

Table 1 Sociodemographic characteristics of adults with and without ADHD in Europe and the US

	Germany (n1=100; n2=100)	Northern Europe (n1=130; n2=149)	UK (n1=101; n2=100)	Europe (n1=331; n2=349)	US (n1=100; n2=100)
Age, mean (SD)
ADHD	38.7 (10.9)	35.3 (11.5)*	33.3 (9.5)*	35.7 (10.9)*	40.7 (12.5)
Non-ADHD	41.8 (12.3)	41.8 (13.5)	40.4 (13.5)	41.4 (13.1)	41.4 (13.9)
Age at the first ADHD diagnosis, mean (SD)
ADHD	9.23 (9.31)	6.78 (7.27)	8.95 (7.90)	8.18 (8.18)	12.34 (9.56)
Non-ADHD	–	–	–	–	–
Male, %
ADHD	49.0	46.9	56.4	50.5	33.0*
Non-ADHD	51.0	51.7	50.0	51.0	50.0
Married/partner, %
ADHD	44.0*	42.3*	51.5*	45.6*	40.0
Non-ADHD	65.0	65.8	69.0	66.5	47.0
College education, %
ADHD	26.0	36.9	51.5	38.1	52.0
Non-ADHD	21.0	39.6	41.0	34.7	52.0
Employed, %
ADHD	55.0	42.3*	72.3	55.3*	62.0*
Non-ADHD	64.0	66.4	61.0	64.2	78.0
Self-reported good health, %
ADHD	48.0*	48.5*	68.3	54.4*	74.0*
Non-ADHD	77.0	76.5	77.0	76.8	91.0
Current smoker, %
ADHD	47.0	45.4*	53.5*	48.3*	24.0*
Non-ADHD	38.0	25.5	24.0	28.7	13.0
Ever alcoholism, %
ADHD	22.0*	13.9*	24.8*	19.6*	7.0
Non-ADHD	8.0	2.7	4.0	4.6	4.0

Notes:

* Significant differences between ADHD and non-ADHD respondents with and without ADHD in each country/region (P<0.05). n₁ and n₂ represent the sample sizes of adults with and without ADHD, respectively, in each country.

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; SD, standard deviation.

Figure 1 Self-reported comorbidities experienced within the past 12 months among adults with and without ADHD in Europe and the US.

Note: The differences between adults with and without ADHD for each comorbidity in each country were significant (P<0.01).
Abbreviations: ADHD, attention-deficit/hyperactivity disorder; GAD, Generalized Anxiety Disorder.

Table 2 Diagnosis history of adults with ADHD in Europe and the US

	Germany (n=100), %	Northern Europe (n=130), %	UK (n=101), %	Europe (n=331), %	US (n=100), %
Prior to diagnosis, consulted with
PCP	49.0	48.5	63.4	53.2	42.0
Psychiatrist	54.0	62.3	45.5	54.7	50.0
Psychologist	43.0	53.9	33.7	44.4	35.0
Pediatrician	10.0	8.5	8.9	9.1	8.0
First diagnosed bya
PCP	19.0	17.1	41.6	25.2	29.0
Psychiatrist	51.0	50.4	26.7	43.3	45.0
Psychologist/therapist	21.0	23.3	10.9	18.8	20.0
Pediatrician	6.0	3.9	4.0	4.6	3.0
Time to first diagnosisa
At first visit	28.6	16.2	10.8	18.6*	42.1
Within 6 months (but not at first visit)	33.0	38.5	36.1	36.1*	47.7
Diagnoses prior to initial ADHD diagnosis
Depression	58.0	46.9	45.5	49.9	50.0
Anxiety	43.0	22.3	33.7	32.0	34.0
Alcoholism	15.0	7.7	11.9	11.2	7.0
Other substance abuse	11.0	13.1	7.9	10.9	11.0
Conduct disorder	36.0	20.0	6.9	20.9*	5.0
Learning disability	26.0	15.4	15.8	18.7	17.0
Bipolar disorder	9.0	9.2	11.9	10.0	10.0
Schizophrenia	4.0	2.3	5.0	3.6	1.0
Autism	5.0	10.8	13.9	10.0*	1.0
Asperger syndrome	6.0	7.7	15.8	9.7*	1.0
Any other mental health conditions	11.0	13.1	7.9	10.9	7.0
Patient experience with ADHD diagnosis
Took too long to get ADHD diagnosis	62.8	46.8	46.7	51.6*	39.0
PCP not knowledgeable about ADHD	47.8	30.8	29.2	35.7	40.5
Had difficulty getting referrals	34.6	27.0	40.5	33.2	22.4
PCP hesitant to diagnosis ADHD	46.6	35.0	39.8	40.2*	25.8

Notes:

* Significant differences between respondents with and without ADHD in Europe and the US (P<0.05);

a a test for the difference between Europe and the US was performed for the variable itself, not for each category of the variable.

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; PCP, primary care physician.

Table 3 Pharmacological and nonpharmacological treatments for adults with ADHD in Europe and the US

	Germany (n=100), %	Northern Europe (n=130), %	UK (n=101), %	Europe (n=331), %	US (n=100), %
Currently treated with ADHD medicationa	54.0	62.3	58.4	58.6	57.0
Methylphenidate	40.0	50.8	35.6	42.9*	10.0
Amphetamine	5.0	4.6	19.8	9.4*	31.0
Atomoxetine	6.0	3.9	6.9	5.4	11.0
Clonidine	9.0	3.1	15.8	8.8*	0.0
Guanfacine	3.0	0.0	1.0	1.2	0
Other	8.0	6.9	3.0	6.0	8.0
Combination	13.0	6.9	17.8	12.1*	3.0
Ever received nonpharmacological Tx	72.0	59.2	74.3	67.7*	54.0
Counseling	50.0	26.9	39.6	37.8	40.0
CBT	34.0	32.3	33.7	33.2*	15.0
Mediation/breathing exercise	28.0	16.9	15.8	19.9	21.0
Diet/supplements	20.0	12.3	27.7	19.3*	10.0
Biofeedback, neurofeedback, or QEEG training	3.0	3.9	5.0	3.9	7.0
Interactive metronome training	8.0	3.9	12.9	7.9	3.0

Notes:

* Significant differences between respondents with ADHD in Europe and the US (P<0.05);

a the percentage of respondents who indicated taking each of the medications listed (multiple choice allowed).

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; CBT, cognitive behavioral therapy; QEEG, quantitative electroencephalogram; Tx, treatment.

Table 4 Self-reported negative impact of ADHD on health and psychosocial functioning among adults with ADHD in Europe and the US

	Germany (n=100), %	Northern Europe (n=130), %	UK (n=101), %	Europe (n=331), %	US (n=100), %	Europe vs US (ADHD)a
						OR	P-value
Negatively impacted on
Overall physical health	65.0	46.2	45.5	51.7	27.0	2.78	<0.001
Overall mental health	73.0	66.9	61.4	67.1	54.0	1.77	0.033
Career success	73.0	63.9	56.4	64.4	62.0	1.08	0.787
Self-esteem	73.0	65.4	67.3	68.3	62.0	1.24	0.428
Relationship with children	53.0	49.4	51.4	51.1	32.2	1.85	0.076
Relationship with significant others	70.6	58.9	61.4	63.2	44.3	1.85	0.036
Relationship with co-workers	61.7	59.3	63.3	61.3	42.1	1.74	0.049
Relationship with all others	72.0	62.3	65.4	66.2	49.0	2.05	0.006
Ability to be a good parent	44.9	45.9	44.9	45.3	37.7	1.27	0.476

Notes:

a ORs are of those reporting negative impacts of ADHD among adults with ADHD in Europe compared with their US counterparts, controlling for sociodemographics and comorbidity variables. OR >1 indicates greater odds of reporting negative impacts of ADHD among adults with ADHD in Europe.

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; OR, odds ratio; SD, standard deviation; vs, versus.

Table 6 Health care resource utilization (in the past 6 months) of adults with and without ADHD in Europe and the US

	Germany (n1=100; n2=100)	Northern Europe (n1=130; n2=149)	UK (n1=101; n2=100)	Europe (n1=331; n2=349)	US (n1=100; n2=100)	Europe vs US (ADHD)a
						Diff/OR	P-value
Total provider visits, mean (SD)
ADHD	12.5 (13.8)*	7.2 (10.5)*	7.8 (10.5)*	9.0 (11.8)*	3.5 (4.6)*	5.48b	<0.001
Non-ADHD	4.3 (9.1)	2.4 (3.7)	2.8 (5.0)	3.1 (6.1)	1.8 (3.9)	–	–
ER visits, (%)
ADHD	30.0*	19.2*	44.6*	30.2*	21.0	1.21c	0.519
Non-ADHD	7.0	7.4	18.0	10.3	11.0	–	–
Hospitalizations, (%)
ADHD	32.0*	15.4*	33.7*	26.0*	13.0	1.58c	0.195
Non-ADHD	5.0	7.4	9.0	7.2	10.0	–	–

Notes:

* Significant differences between adults with and without ADHD in each country/region (P<0.05);

a the figures above show the differences in health care resource utilization between adults with ADHD cohorts in Europe and the US, controlling for the interaction between ADHD status and region, as well as sociodemographics and comorbidity variables

b differences in the least squares means. A difference of more than zero indicates more frequent visits to health care providers by adults with ADHD in Europe

c differences in the least squares means, expressed in terms of OR. OR >1 indicates greater odds of using resources among ADHD cohorts in Europe. n₁ and n₂ represent the sample sizes of adults with and without ADHD, respectively, in each country.

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; Diff, difference; ER, emergency room; OR, odds ratio; SD, standard deviation; vs, versus.

Table 5 Level of work productivity/activity impairment (during the past week) of adults with and without ADHD in Europe and the US

	Germany (n1=100; n2=100), Mean (SD)	Northern Europe (n1=130; n2=149), Mean (SD)	UK (n1=101; n2=100), Mean (SD)	Europe (n1=331; n2=349), Mean (SD)	US (n1=100; n2=100), Mean (SD)	Europe vs US (ADHD)a
						Diff	P-value
Absenteeism
ADHD	19.5 (28.2)*	13.1 (22.1)*	24.0 (26.4)*	19.4 (26.1)*	8.0 (20.5)	10.29	0.006
Non-ADHD	6.3 (21.4)	3.1 (13.2)	6.3 (21.6)	4.9 (18.3)	2.5 (9.8)	–	–
Presenteeism
ADHD	45.0 (29.6)*	38.7 (26.5)*	52.1 (27.7)*	45.8 (28.3)*	28.0 (27.1)*	12.72	0.003
Non-ADHD	15.9 (22.3)	16.1 (23.2)	19.6 (23.6)	17.0 (23.0)	12.8 (24.3)	–	–
Overall work impairment
ADHD	52.8 (32.8)*	46.4 (28.4)*	60.8 (30.4)*	54.0 (31.1)*	32.2 (30.4)*	17.42	<0.001
Non-ADHD	19.7 (28.2)	18.4 (25.8)	24.4 (29.0)	20.4 (27.4)	13.9 (25.2)	–	–
Activity impairment
ADHD	56.6 (25.9)*	50.6 (26.4)*	55.5 (27.0)*	53.9 (26.5)*	41.9 (31.8)*	4.82	0.356
Non-ADHD	29.4 (30.8)	24.5 (27.5)	31.1 (33.0)	27.8 (30.2)	17.0 (26.0)	–	–

Notes:

* Significant differences between adults with and without ADHD in each country/region (P<0.05);

a the figures above present the differences in the least squares means of the outcomes between respondents with and without ADHD in Europe and the US, controlling for the interaction between ADHD status and region and for sociodemographics and comorbidity variables. A difference of more than zero indicates a higher level of work productivity/activity impairments among adults with ADHD in Europe. n₁ and n₂ represent the sample size of adults with and without ADHD, respectively, in each country.

Abbreviations: ADHD, attention-deficit/hyperactivity disorder; Diff, difference; SD, standard deviation; vs, versus.