
Evidence Based Treatment for Lasting Recovery
Table of Contents
There is a vast body of evidence to show that residential treatment for addictions can enable people to lead drug-free lives.
At Castle Craig, we strive to provide the highest standard of treatment and the results show that our treatment is effective. Castle Craig has produced several outcome studies over a number of years and these have shown consistently good results.
Many of our studies use the Christo Inventory for Substance Misuse Services (CISS). This independent tool is a widely used outcomes tool in the UK.
Oliver Barnes Report
Castle Craig commissioned an independent review of the evidence supporting Castle Craig’s treatment programme. Read the review paper here.
Addiction Treatment Research Reports
In this section, we are making available a number of addiction treatment research reports that we think are relevant to those interested in learning more about the disease of addiction, as well as seeing the detailed evaluations about Castle Craig.
We do our own research and we commission independent bodies to research the efficacy of our services to prove that they are of the highest standard possible. This includes an independent analysis of our outcomes data.

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Evaluation of Patient Outcomes 2015
This study followed 233 patients admitted to Castle Craig between 2011-2012 for alcohol, drug and gambling addictions. The patients in this study were all from Holland.
75% of patients completed treatment, others prematurely self-discharged against medical advice, and a small number were prematurely discharged for rule violations or on medical grounds.
We received a 70.9% response rate (158 of the sample) which showed that:[1]
- 91.8% of followed-up patients improved, 8% remained the same, and none got worse.
- 73.4% were totally abstinent from all drugs or alcohol at follow-up.
- 81.6% achieved low problem severity at follow-up.
It concludes that not only do a vast number of patients leaving Castle Craig show significant improvements in their quality of life, and drug and alcohol use habits, but these changes continue for extended periods of time. A secondary finding is that patients readmitted to treatment following a relapse are significantly more likely to achieve a good outcome.
To download the full study download this PDF.
Outcomes for Patients at Castle Craig Hospital 2010
Outcomes evaluation for one patient with a primary gambling addiction, 89 drug and 66 alcohol-dependent patients from the Netherlands entering Castle Craig Hospital between 7th May 2007 to 16th December 2008 and staying in treatment for more than 1 day. This study finds complete abstinence at follow up in over 61% of cases.
Summary of findings
- One patient with a primary gambling addiction, and 89 drug and 66 alcohol-dependent patients from the Netherlands entered Castle Craig Hospital between 7th May 2007 to 16th December 2008 and stayed in treatment for more than 1 day.
- Most patients were addicted to alcohol or cocaine.
- Patients were generally quite dysfunctional at intake. The average intake CISS total score of the 156 patients was 11.0 and their greatest problems were with drug or alcohol use, lack of support, psychological problems, lack of occupation, and poor health.
- Drug-dependent patients tended to have greater problems with social functioning, viral risk, and criminality.
- Alcohol-dependent patients tended to have greater problems with health and working relationships.
- Patients were generally more dysfunctional than those attending outpatient alcohol or drug services (based on the CISS comparison scores see Appendix).
- The patients’ average wait between referrals to treatment entry was 7.3 weeks.
- 62% of patients completed treatment, 32% of patients prematurely self-discharged against medical advice, 6% of patients were prematurely discharged for rule violations, and one patient was prematurely discharged on medical grounds.
- The average treatment duration for patients’ taking a planned discharge was 21 weeks, and the average treatment duration for prematurely discharged patients was 9 weeks.
- Premature treatment discharge was a little more likely among the drug users.
- Follow-ups were successfully completed on 113 of the 156 patients (72.4% response rate).
- Thirty-nine patients could not be contacted and four patients died.
- The average follow-up period was 67 weeks.
- 92% of followed-up patients improved, 8% remained the same, and none got worse.
- 63% of patients completing treatment did well, whereas only 35% of patients taking an unplanned discharge (for whatever reason) had a good outcome.
- The average intake CISS score of the 113 followed-up patients was 10.6 and the average follow-up CISS score was 4 indicating a highly significant improvement in general functioning.
- Reductions in drug/alcohol use at follow-up were accompanied by improvements in all other CISS domains.
- Even those who were not totally abstinent at follow-up appeared to have benefited from their experience in treatment, probably by gaining a period of respite during which to recover from the consequences of their excessive drinking or drug use.
- The following success rates are conservatively based by including all 156 patients on the assumption that the 43 patients, not followed-up (response rate = 72.4%) showed no improvement or otherwise had poor outcomes.
- Being totally abstinent from all drugs or alcohol at follow-up 46%
- Achieving low problem severity at follow-up (CISS < 6, see appendix) 52%
- Showing any reduction in measured levels of dysfunction 69%
In reality, the success rates are most likely to be higher because some of the missing patients would not have been contactable due to having recovered and being in full time occupation.
- The following success rates are thus more liberally based by including the 4 patients that died but not including the other 39 patients that could not be contacted for follow-up (n = 117).
- Being totally abstinent from all drugs or alcohol at follow-up 61%
- Achieving low problem severity at follow-up (CISS < 6, see appendix) 69%
- Showing any reduction in measured levels of dysfunction 89%
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Outcomes for Cocaine Addicted Patients at Castle Craig Hospital 2007
Outcomes evaluation for all cocaine-addicted patients admitted between 15th January 2004 and 31st July 2006 and staying in treatment for more than one day. This study finds complete abstinence at follow-up in 66% of cases.
Summary of findings
- The sample comprised all cocaine-addicted patients who entered treatment between 15th January 2004 to 31st August 2006 and stayed in treatment for one or more days.
141 patients met these criteria, 74 from Scotland, 66 from the Netherlands, and 1 from the USA. - Scottish patients’ average age of 34 years was significantly lower than the Dutch patients’ average age of 37 years.
- Scottish patients’ average CISS total score of 14.1 was significantly higher than the Dutch patients’ average CISS total score of 12.6.
- Patients’ greatest problems were with drug or alcohol use, lack of occupation, lack of support, and psychological problems.
- Patients dependent only on cocaine and alcohol tended to have fewer problems with Viral Risk and Criminal Behaviour.
- Patients with higher levels of dysfunction at intake tended to either drop out of primary or go on to extended care.
- In comparison to those entering extended care, dropouts from primary (excluding 21 primary completers) were more likely to have greater social functioning problems, greater criminal involvement, and greater compliance problems.
- 48% of patients left treatment prematurely. However, 92% of patients completed detoxification.
- The average treatment duration of 19 weeks for patients completing treatment was significantly longer than the prematurely discharged patients’ average treatment duration of 8 weeks.
- The average CISS total score of 12.3 for patients completing treatment was significantly lower than the prematurely discharged patients’ average CISS score of 14.5.
- At treatment entry, completers tended to have fewer social functioning problems, fewer occupation problems, less criminal involvement, and fewer compliance problems.
- Patients’ age, gender, nationality, and drug use patterns were unrelated to premature discharge.
- Follow-ups were successfully completed on 107 of the 141 patients (76%).
- The average follow-up period was 79 weeks.
- Patients completing treatment were significantly more likely to have a good outcome.
- The average treatment duration (16 weeks) of the 84 good-outcome patients was significantly longer than the average treatment duration (10 weeks) of the 57 poor-outcome patients.
- Patients entering extended care were significantly more likely to have a good outcome.
- Patients’ gender, nationality, drug use pattern, age, and CISS total score at treatment entry were unrelated to the outcome.
- There was no significant relationship between CISS total scores at treatment entry and subsequent outcomes among the 60 patients who did not go into extended care.
- Among the 81 patients entering extended care, the average CISS score of 12.8 for patients with a good outcome was significantly lower than the poor outcome patients’ average CISS score of 14.2.
- Reductions in all of the 10 CISS outcome domains were highly significant. Thus indicating that reductions in drug/alcohol use were generally accompanied by improvements in all other aspects of the patients’ lives.
- For all 141 patients, 92% successfully completed detoxification.
For all 141 patients, the following ‘Success’ rates are conservatively based on the assumption that the 34 patients not followed-up all showed no improvement or otherwise had poor outcomes.
- Being totally abstinent from all drugs or alcohol at follow-up 46%
- Achieving low problem severity at follow-up (CISS < 7, see appendix) 60%
- Showing any reduction in measured levels of dysfunction 74%
For the 73 Patients who completed all their treatment, the following ‘Success’ rates are conservatively based on the assumption that the 10 patients not followed up all showed no improvement or otherwise had poor outcomes.
- Being totally abstinent from all drugs or alcohol at follow-up 66%
- Achieving low problem severity at follow-up (CISS < 7, see appendix) 78%
- Showing any reduction in measured levels of dysfunction 84%
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Treating Addiction Since 1988
Outcomes for Lanarkshire Patients at Castle Craig Hospital 2004
Outcomes evaluation for 28 drug and 61 alcohol-dependent patients (48 males, 41 females) from the Lanarkshire area admitted between 5th August 2002 to 20th February 2004 and staying in treatment for more than 3 days, who left follow-up contact addresses or telephone numbers with the hospital. The study finds complete abstinence at follow-up in 45% of cases.
The 2004 evaluation for Lanarkshire patients admitted between 5th August 2002 and 20th February 2004.
Summary of findings
- 28 drug and 61 alcohol-dependent patients (48 males, 41 females) from the Lanarkshire area entered Castle Craig between 5th August 2002 to 20th February 2004 and stayed in treatment for more than 3 days and also left follow-up contact addresses or telephone numbers with the hospital.
- Their average length of stay in primary treatment was 5 weeks. 35% then went on to extended care where their average length of stay was 10 weeks.
- Females were more likely to enter extended care than males.
- 67 of 89 patients were followed up on average about 50 weeks later. 89% improved, 9% remained the same, and 2% got worse.
- These patients were generally quite dysfunctional at intake. The average intake CISS total score of the 67 patients was 11.9 and their greatest problems at intake were with drug or alcohol use, lack of occupation, lack of support, psychological problems and health problems.
- Drug-dependent patients tended to have greater problems with social functioning, viral risk, criminality, compliance and working relationships. They were thus also more likely to leave primary treatment prematurely.
- Patients were generally more dysfunctional than those attending outpatient alcohol or drug services (based on the CISS comparison scores see Appendix).
- The average follow-up CISS score was 4.1, thus indicating a highly significant improvement.
- Reductions in drug/alcohol use at follow-up were accompanied by improvements in all other CISS domains.
- Even those who were not totally abstinent at follow-up appeared to have benefited from their experience in treatment, probably by gaining a period of respite during which to recover from the consequences of their excessive drinking or drug use.
- The following ‘success’ rates for all Lanarkshire patients are conservatively based on the assumption that the 21 patients not followed up all showed no improvement or otherwise had poor outcomes.
- Being totally abstinent from all drugs or alcohol at follow-up 45%
- Achieving low problem severity at follow-up (CISS < 6, see appendix) 54%
- Showing any reduction in measured levels of dysfunction 67%
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Outcomes of NHS Funded Alcohol Dependent Patients at Castle Craig Hospital 2002
Outcomes evaluation for 60 alcohol-dependent patients funded by Fife NHS Health Board area admitted between 12th December 1999 to 12th March 2002 and staying in treatment for more than 3 days. Follow up at 1.3 years after discharge shows 90% improved, 45% still abstinent. The study finds complete abstinence at follow up in 45% of cases.
Their average length of stay in primary treatment was 5.3 weeks. 20% then went on to extended care were their average length of stay was 10.4 weeks.
Even those who were not totally abstinent at follow-up appeared to have benefited from their experience in treatment, probably by gaining a period of respite during which to recover from the consequences of their excessive drinking.
The following ‘success’ rates for all patients from Fife are conservatively based on the assumption that the 11 patients not followed-up all showed no improvement or otherwise had poor outcomes.
Extended Care Unit Follow Up Study 2000
Outcomes evaluation of 206 clients referred to the Extended Care Unit at Castle Craig between 31st September 1997 and 31st August 1999. All clients, including those leaving without completing treatment were included in the study, no one was excluded.
The study finds that 31% of the total group had achieved continuous unbroken abstinence, and an additional 13% of the total group were classified as in a good outcome category, (i.e. no more than 3 brief relapses and with a minimum period of 3 months continuous abstinence prior to assessment.) As well as detailed statistics, the paper contains a discussion on the cost-effectiveness of residential treatment for addiction.
Extended Care follow-up study, 1999
Dr Margaret McCann, MB BCh Medical Director, Castle Craig Hospital
A study in 1999 investigated the results of 96 severely dependent patients who were admitted into the extended care programme after the first phase of treatment was complete.
The results showed that 62% of those who completed treatment had remained abstinent for a minimum, of 3 months and up to a minimum of 420 days.
Methadone Increases Craving for Heroin
A study of chronic opiate users receiving methadone substitution treatment.
By H. Valerie Curran et Al, Department of Psychology, University College London. The Camden and Islington NHS Trust, London, UK. The project took place at the Camden and Islington Substance Misuse Services, an outpatient service in London.
Aims: To assess the acute-on-chronic effects of methadone on drug craving, mood and cognitive and psychomotor functioning in patients on long-term methadone substitution treatment.
Design and participants: A double-blind, cross-over design was used to compare the effects of a 33% increase in patient’s daily dosage of methadone with a matched placebo linctus. Eighteen patients completed the study; all were assessed pre-and post-drug on two separate testing days.
Findings: Methadone significantly increased both positive craving (expected positive effects) and negative craving (expected relief of withdrawal discomfort) for heroin. Patients were unable to distinguish between methadone and placebo treatments. No differences between treatments emerged in cognitive or psychomotor effects. In terms of mood, patients were more alert and more contented following placebo than following methadone.
Conclusions: Additional methadone may “prime” cravings for heroin in methadone substitution patients.
Addictions Psychiatry in Practice, Summer 1997
Read the paper by Dr Margaret McCann CEO and Co-Founder of Castle Craig Hospital.
Supported by statistics, it gives a comprehensive overview of the UK’s addiction problem and the resources and methodology available to meet this growing challenge. The underlying message is that recovery is certainly possible and ‘virtually all studies show patients are better off after treatment than before.’
The Lord President’s Report On Alcohol Misuse And The Implication For Alcoholism Services In Scotland
Presented to: 36th International Congress on Alcohol and Drug Dependence Glasgow August 19, 1992.
this paper reviews the specialist alcoholism residential services in Scotland for each Health Board Area following the publication of the Lord President of the Council report “Action Against Alcohol Misuse”. A comparison is made of Scotland’s existing services with those in Norway and Alberta.
The report concludes that the extent and the seriousness of the illness of alcoholism together with alcohol-related harm in Scotland are greatly underestimated and states:
‘Doctors, Health Boards and the government must have more compassion for the sick alcoholic who deserves treatment and is worthy of our care.’
The Impact of the NHS Reforms in Scotland on a Non-NHS Patient Facility which uses the ‘Minnesota Model’ Approach to Treatment
This report by Peter J McCann, Chairman and Co-Founder of Castle Craig Hospital, dates from around 1995. It details the evolution of funding for treatment from public health sources in the light of the various NHS reforms that have taken place, since the Hospital’s foundation in 1988. It makes the point that running costs at that time were comparable with costs in the NHS for similar services.
The Effectiveness of Residential Rehabilitation Services in the Treatment for Drug and Alcohol Problems
The report reviews and compares the extent of the Drug and Alcohol problems in Scotland and England and the treatment available at that time. It highlights the dearth of funding for residential treatment in certain regions of Scotland and the absence of patient choice. It concludes:
‘It is clear on the basis of the research that has been undertaken that abstinence-based residential rehabilitation services can have a significant beneficial impact on facilitating individuals recovery from dependent drug and alcohol use. ‘
Conferences We Attend
We regularly attend conferences in the UK and abroad. In addition, members of our staff have travelled worldwide to hear and contribute to the latest developments in addiction theory and treatment practice.
This ensures we remain an authority on addiction treatment and allows our knowledge to shape our treatment programme and the treatment experiences of our patients.
White Papers
Addiction Treatment Outcome Studies
New Research Findings: Hyperbaric Oxygen Therapy is of “Profound Importance” to Opiate Detox
The Impact of the NHS Reforms using the “Minnesota Model” Approach
How Can Castle Craig Help?
How Do I Pay For Rehab?
One concern we sometimes hear from people is how they will fund their rehab treatment. The cost of rehab varies depending on what kind of accommodation you choose. You can pay for treatment at Castle Craig privately, or through medical insurance, and some people receive funding through the NHS.
How Long Is the Rehab Programme?
Residential rehab treatment starts at four weeks and can go up to 12+ weeks. Research shows us that the longer you stay in rehab and are part of the residential therapy programme, the longer the likelihood of continued abstinence and stable recovery.
Who Will I Speak to When I Call?
When you call you will reach our Help Centre team who will give you all the information you need to help you decide whether to choose treatment at Castle Craig. Once you have decided that you would like to have a free screening assessment you will be put in touch with our admissions case managers who will guide you through the admissions process.
What Happens at the End of My Treatment?
Castle Craig thoroughly prepares patients before departure by creating a personalised continuing care plan which is formulated following discussions with the medical and therapeutic team. We offer an online continuing care programme which runs for 24 weeks after leaving treatment, in order to ensure a smooth transition back into your everyday life. Patients leaving treatment automatically join our Recovery Club where they can stay connected via our annual reunion, events, online workshops and recovery newsletters.