European ADHD in substance use disorders prevalence study.

ADHD (Attention Deficit/Hyperactivity Disorder) is increasingly recognised as
an invalidating and highly prevalent disorder in children and in adults 1.
Patients with ADHD experience inattention, restlessness and impulsivity
throughout there life. Moreover, ADHD is a highly comorbid disorder. Other
psychiatric disorders, such as personality disorders, mood and anxiety
disorders, and substance use disorders are common among adults with ADHD. Among
adult patients with substance use disorders (SUD), ADHD is a common diagnosis,
with a prevalence between 15 and 30 % found in (mostly American) studies 2.
European prevalence studies are scarce. However, clinical experience points to
a similar prevalence among patients in European addiction treatment centres.
ADHD in adults is a relatively new diagnosis; in a lot of European countries,
psychiatric services and especially addiction treatment services lack the
expertise necessary for screening, diagnosing and treating ADHD in addicted
patients 3. Due to symptom overlap, ADHD is not easily differentiated from
other frequently occurring psychiatric disorders (such as bipolar disorder and
borderline personality disorder) 4,5,6. A reliable screening procedure would be
most helpful in the development of adequate treatment services 7.
There is mounting evidence that ADHD is an important (but up to now scarcely
studied) risk factor in the development and persistence of addiction. ADHD is
associated with an early onset of substance abuse, a more rapid transition into
more severe types of substance abuse, and a more problematic course of to the
substance use disorders, including more difficulty in reaching remission 8.
The available studies (done mostly in the United States) point to an ADHD
prevalence of 10-25% in SUD patients, depending on setting and type of
addiction studied. Data on ADHD prevalence in European countries are scarce, a
systematic European prevalence study has not yet been executed. Up to a few
years ago, most of these patients would remain undiagnosed, due to lack of
recognition of the disorder and lack of treatment expertise. Fortunately, a
growing awareness among patients and health providers has helped to make this
disorder more visible.
The relevance of adult ADHD in SUD patients remains unclear. Treatment of ADHD
in childhood helps to prevent the development of addiction in adulthood 9.
However, controlled studies of the effect of ADHD treatment on the prognosis of
addiction are still lacking. Clinical experience shows positive benefits of
treatment mainly on the ADHD symptomatology (inattention, hyperactivity and
impulsivity). There is only anecdotal evidence of a positive influence of ADHD
treatment on the severity and course of the substance use disorders.
This study can be seen as a first step in tackling the problem of ADHD in
addiction. Having a better knowledge of the size and scope of the ADHD in SUD
patients will add to a better understanding of the relevance of ADHD in this
patient group, and of the relation between these two chronic disorders. Only
then, controlled studies of the efficacy of ADHD treatment interventions will
be possible. The current study will, therefore, contribute to the development
of
(1) an adequate program of detection, diagnosis and treatment of ADHD in
addicted patients and
(2) effective prevention methods for SUD in ADHD children/adolescents/young
adults.
This study aims to raise the awareness of this frequently occurring, quite
treatable condition, and to confirm a high prevalence among patients with
substance use disorders. These results should stimulate European addiction
centres to develop treatment programs for these patients.

- to document the presence of adult ADHD in different European populations of
adult patients referred for addiction treatment
- to obtain a reliable estimate of the prevalence of ADHD among adult patients
with substance use disorders
- to test an internationally used screening instrument for adult ADHD (ASRS) on
its accuracy (especially in differentiating from other psychiatric disorders)
and usefulness in this specific patient population
- to validate the adult ADHD screening and diagnostic instruments for the
participating countries
- to gather knowledge about the relationship between ADHD and the onset and
course of SUD, by comparing ADHD patients with patients without ADHD for
comorbidity, age of SUD onset and functional outcome
- to explore the feasibility of multi-site ADHD research in this patient
population

a descriptive, prospective and cross-sectional study, consisting of two parts:
1. screening for ADHD in 500 newly referred patients, by means of the
instruments listed below
2. further diagnostic assessment of 230 patients
(+ screening: - screening = 1:1)
The ADHD prevalence, obtained in these centres, will be used to fix the cut-off
points for the screening instrument, and to determine the prevalence in the
patients who did the screening part only.

Burden associated with participation: limited: filling in of screening
questionnaire (15 minutes), and possibly participating in a full diagnostic
assessment (120 minutes.
Benefits:
* participants: may receive an indication of a possible diagnosis of ADHD and
possibly further diagnostic assessment for this disorder and other often
occurring disorders within this population, with the possibility of proper
treatment.
* participating centres: - increased experience in adult ADHD in addicted
patients
- participation in a first European multi-centre study on this topic
- participation in a European Network of Scientist-Practitioners in this
specific area (ICASA)