The Psychiatrist (2009) 33: 88-91. doi: 10.1192/pb.bp.108.020107
© 2009 The Royal College of Psychiatrists
Cocaine use and dependence in clients attending a drug treatment centre in Dublin
Mpho Abel Thula, Registrar
Drug Treatment Centre Board, Trinity Court, 30-31 Pearse Street, Dublin,
Ireland, email:
poster6{at}yahoo.com
Declaration of interest
None.

Abstract
AIMS AND METHOD
To assess the number of cocaine-dependent clients attending a typical
addiction clinic, using urine drug testing for screening and a structured
clinical interview for diagnostic assessment.
RESULTS
Of the 419 clients whose urine records were analysed, 38 were regular users
of cocaine (9.1%), with at least half of their urine samples positive for
cocaine in a 12-week period; 84.2% of these regular users of cocaine satisfied
the criteria for cocaine dependence(7.7% of the total number of those
attending the clinic).
CLINICAL IMPLICATIONS
Publicly funded addiction treatment centres in Ireland are mostly designed
for the treatment of opiate addiction. There is, however, a significant
problem of concomitant cocaine dependence in these centres. Increased
availability of psychological/behavioural treatment programmes with proven
efficacy in cocaine addiction may help improve overall treatment outcome.

Introduction
The Drug Treatment Centre Board in Dublin runs the largest substance
misuse
treatment centre in Ireland, with over 500 clients from
all over Dublin
registered with the clinic. The vast majority
are on substitution treatment
for opiate dependence. However,
cocaine use is increasingly becoming a major
problem in this
group as the use of the drug in the country continues to
increase.
In January 2008, a report by the National Advisory Committee
on
Drugs, and the Drug and Alcohol Information and Research
Unit noted a
significant increase in lifetime cocaine prevalence
rates among all adults
(15-64 years of age) in Ireland, from
2.5% in 2002/2003 to 5.1% 2006/2007
(
National Advisory Committee on Drugs,
2008).
In a national multi-site evaluation in the USA
(
Hubbard et al, 1997),
cocaine misuse was found in 42% of those beginning treatment
with methadone
and in 22% of the same group at 1-year follow-up.
Cocaine misuse during opioid
maintenance treatment has been
associated with poor treatment outcome
(
DeMaria et al, 2000);
a high risk of HIV infection (
Bux et
al, 1995); higher levels
of family, medical, vocational and
legal problems; and continued
focus on drug-related criminal activity
(
Kosten et al, 1987).
Clients with cocaine dependence also have a greater risk of
suicidal behaviour
(
Marzuk et al,
1982).
The aim of the study was to quantify the number of regular users of cocaine
in the treatment centre, using a cut-off point of half weekly urine samples
testing cocaine positive in a 12-week period. The study also sought to find
out what proportion of this cohort of regular users fulfil dependence criteria
as assessed by the Structured Clinical Interview for DSM-IV Axis I disorders
(SCID-I) (First et al,
2002).

Method
Participants
Using the database from the clinic laboratory, information was
obtained
about urine drug test results for all clients attending
the drug treatment
centre over a 12-week period between 7 August
and 30 October 2007 (clients are
required to submit a urine
sample for drug analysis once a week as part of the
treatment
programme). The results were then analysed to find the number
of
clients whose urine samples tested positive for cocaine
in more that 50% of
cases. Only those who provided more than
four samples over the period of
analysis and had provided a
sample within 3 weeks of the commencement date of
the study
were selected for further assessment. All eligible candidates
provided written voluntary consent for involvement in the study.
The study and
all its procedures were approved by the drug
treatment centre board ethics
committee.
Diagnostic measures
Participants fulfilling the study criteria were assessed for cocaine
dependence using SCID-I. The assessment was carried out by a psychiatrist.

Results
Participants
The data from the laboratory showed that 419 clients had submitted
a
minimum of four urine samples for drug testing in the 12-week
period, of which
38 (9.1%) met the inclusion criteria of at
least half for cocaine positive
samples in this period.
Of the 38 candidates who were eligible for assessment for cocaine
dependence, 2 did not give their consent to participate in the assessment
(5.3%) and 3 (7.9 %) could not be assessed for other reasons (1 was in prison,
1 had since stopped attending the clinic and 1 had a very poor attendance
record). Therefore, 33 of the eligible candidates were assessed for cocaine
dependence. The flow of candidates through the study up to the assessment
stage is presented in Fig.
1.
Outcomes
Of the candidates who were assessed using SCID-I, 32 satisfied
the criteria
for cocaine dependence and 1 did not (
Table
1).
Therefore, 84.2% of all eligible candidates satisfied the
DSM-IV
criteria for dependence and 2.6% did not. Of the 32 candidates
who
satisfied the DSM-IV criteria for dependence, 3 (9%) did
not meet the criteria
in the last month before the diagnostic
assessment; 25 (86%) of those who met
the criteria for cocaine
dependence in the previous month had physiological
dependence
to the drug.

Discussion
The study aimed to assess the extent of cocaine dependence among
clients
attending treatment for opiate addiction. The results
showed that 9.1% of
clients attending an opioid dependence
treatment clinic were regular users of
cocaine and 84.2% of
these satisfied the DSM-IV criteria for cocaine
dependence
as assessed by SCID-I. In total, 7.7% of clients attending the
clinic had cocaine dependence. This compares well with previous
studies of
cocaine dependence in this population group, where
9% of daily cocaine misuse
was found in patients 6 months after
admission into methadone maintenance
treatment, falling to
6% after 12 months
(
Dobler-Mikola et al,
2005). Although most
available data tend to quote cocaine use and
cocaine misuse,
this study set out to find the rates of cocaine dependence in
a chosen population group.
The 2007 report from the National Advisory Committee on Drugs in Ireland
noted that treatment programmes in Ireland are not designed for stimulant
users and that opiate-based treatment services have to deal with increasing
numbers of individuals presenting with cocaine-related problems
(National Advisory Committee on Drugs,
2007). Cocaine use is higher among individuals with opiate
dependence in maintenance treatment than among the general population
(Haasen et al, 2004).
Although effective substitution pharmacological treatment is available for
opioid dependence, there is no similarly effective intervention for primary
cocaine dependence (de Lima et al,
2002). However, psychosocial interventions, mainly contingency
management and cognitive-behavioural approaches, have been effective in the
management of cocaine addiction (Rawson
et al, 2002).
Drug treatment programmes focusing mainly on opiate addiction need to adapt
so that they can deal with increasing numbers of cocaine users
(National Advisory Committee on Drugs,
2007). This will require resources and training in
non-pharmacological approaches that have been shown to be effective in
treating cocaine addiction.
Limitations
The sample of those who were eligible for assessment was quite small. Of
the 38 clients eligible for diagnostic assessment, 5 (13%) could not be
assessed, which could have affected the outcome. At any given time, patients
who fail to stabilise on opioid agonist maintenance are placed on a low-dose
regime for a defined period of time as part of contingency management and do
not have to provide urine samples. Therefore, they would not be included in
this study. This group tend to be more likely to be misusing cocaine as well
as opiates. Excluding this group could have underestimated the prevalence of
cocaine dependence in the clinic.
Diagnostic assessment was carried out by one individual which could have
resulted in bias.
Despite the limitations of the study, the results show that there is a
significant cocaine dependence problem among clients attending opioid
treatment centres. Appropriate services need to be put in place to address
this.

Acknowledgments
I thank the clients at the Drug Treatment Centre, Dublin, who
took part in
the study and Dr Brion Sweeny for his guidance.

References
- BUX, D. A., LAMB, R. J. & IGUCHI, M. Y. (1995)
Cocaine use and HIV risk behavior in methadone maintenance patients.
Drug and Alcohol Dependence,
37, 29-35.[CrossRef][Medline]
- DE LIMA, M. S., DE OLIVIERA SOARES, B. G., REISSER, A. A., et
al (2002) Pharmacological treatment of cocaine dependence: a
systematic review. Addiction,
97, 931
-949.[CrossRef][Medline]
- DEMARIA, P. A. JR., STERLING, R. & WEINSTEIN, S. P.
(2000) The effect of stimulant and sedative use on treatment
outcome of patients admitted to methadone maintenance treatment.
American Journal of Addictions,
9, 145-153.[CrossRef][Medline]
- DOBLER-MIKOLA, A., HÄTTENSCHWILLER, J., MEILI, D., et
al (2005) Patterns of heroin, cocaine and alcohol abuse
during long-term methadone maintenance treatment. Journal of
Substance Abuse Treatment, 29, 259
-265.[CrossRef][Medline]
- FIRST, M. B, SPITZER, R. L, GIBBON, M., et al
(2002) Structured Clinical Interview for
DSM–IV–TR Axis I Disorders (research version, patient
edition). Biometric Research, New York Psychiatric
Institute.
- HAASEN, C., PRINZLEVE, M., ZURHOLD, H.,et al
(2004) Cocaine use in Europe: a multi-centre study.
European Addiction Research,
10, 139
-146.[CrossRef][Medline]
- HUBBARD, R. L., CRADDOCK, S. G., FLYNN, P. M., et al
(1997) Overview of 1-year follow-up outcomes in the Drug Abuse
Treatment Outcome Study (DATOS). Psychology of Addictive
Behaviors, 11, 261
-278.[CrossRef]
- KOSTEN, T. R., ROUNSAVILLE, B. J. & KLEBER, H. D.
(1987) A 2.5-year follow-up of cocaine use among treated opioid
addicts: have our treatments helped? Archives of General
Psychiatry, 44, 281
-284.[Abstract/Free Full Text]
- MARZUK, P. M., TARDIFF, K., LEON, A. C., et al
(1982) Prevalence of cocaine use among residents of New York City
who committed suicide during a one-year period. American Journal of
Psychiatry, 149, 371
-375.
- NATIONAL ADVISORY COMMITTEE ON DRUGS (2007)
An Overview of Cocaine Use in Ireland II. The
Stationery Office Dublin.
- NATIONAL ADVISORY COMMITTEE ON DRUGS & THE DRUG AND ALCOHOL
INFORMATION AND RESEARCH UNIT (2008) Drug Use in
Ireland and Northern Ireland: First Results from the 2006/2007 Drug Prevalence
Survey. NACD.
- RAWSON, R. A., HUBER, A., McCANN, M. J., et al
(2002) A comparison of contingency management and
cognitive-behavioral approaches during methadone maintenance treatment for
cocaine dependence. Archives of General Psychiatry,
59, 817
-824.[Abstract/Free Full Text]