The prescription of methadone as a treatment method began in the Netherlands in 1968. During the first few years, methadone was prescribed to morphine dependent patients. Following the introduction of heroin in the Netherlands in 1972, treatments with methadone were primarily directed towards achieving abstinence from heroin addiction. Generally, these methadone reduction programs suffered from high drop-out rates, and there was a serious threat that they would loose contact with many addicts. Paralleling the rapid increase in the number of heroin addicts during the 1970s, and the introduction of HIV/AIDS in the mid 1980's, the aim of oral methadone prescription in the Netherlands shifted from achieving abstinence towards achieving stabilization and the reduction of drug related harm. Prevention of risk-behaviors and the provision of medical care through regular contact with the addict became the primary objective of methadone maintenance programs for those patients who refused counseling and continued their use of illicit drugs. In this period of increasing risk of infection and increasing necessity - for the purpose of AIDS-prevention - to at least stay in contact with the addict, the high drop-out rates in the methadone reduction programs were considered unacceptable by both treatment agencies and policy makers.
Currently, many of the Dutch methadone programs can be referred to as so-called "low-threshold" maintenance programs, characterized by the absence of mandatory counseling, absence of sanctions in case a urine test reveals illicit substance use, and relatively low dosages of methadone. These programs are aimed at the reduction of health risks and improvement of the quality of life of those addicts who are unable or unwilling to give up their drug use. Due to their low-threshold character, a high percentage of heroin addicts in the Netherlands (50-80%), including "poor performers", are reached by these programs (Bieleman et al., 1995; NDM, 2001).
Although no controlled studies on the effectiveness of the methadone treatments have been conducted in the Netherlands, there is extensive clinical experience with dispensing methadone, and naturalistic follow-up studies provide some insight into their outcomes. In 1988, a survey was conducted on the dispensing of methadone in the Netherlands (Driessen, 1990). According to this study, the estimated number of heroin addicts in the Netherlands then was 24,000 (1). Of these, an estimated 17,000 addicts (71% of the total) had been in contact with a treatment program at least once during the previous year (Figure 1). Among this group, approximately 4,500 had been in drug-free treatment (e.g. inpatient and outpatient detoxification, residential treatment centers, therapeutic communities, and drug-free prison programs). Approximately 12,500 had received methadone on a regular basis, most of them for many years (the average time in treatment amounted to approximately 8 years). According to the treatment staffs of the methadone maintenance programs, 36% of the 12,500 methadone patients (4,500 persons) were well regulated, meaning that they exhibited little or no drug use, were compliant with treatment efforts and showed some degree of social integration. Another 40% (5,000 persons) were not adequately regulated, meaning that they had frequently used illicit drugs, had been less than compliant with treatment efforts and achieved low levels of social integration. Finally, 24% (3,000 persons) were considered as being extremely problematic. These persons used various illicit substances on a daily basis, manifested symptoms of physical and/or mental problems, exhibited high levels of criminality, and showed no evidence of social integration.

Figure 1. Treatment situation in the Netherlands

Data from 1991 indicate that three-quarters (78%) of all methadone maintenance patients had continued using heroin, and more than a third (37%) were still using heroin on a daily basis (Driessen, 1992). At that time, nearly all methadone maintenance programs offered a broad spectrum of additional services, including psychosocial counseling, medical counseling and treatment, social work and - in some centers - psychotherapy. Despite their availability, however, only 49% of these clients took advantage of social work assistance, 28% took part in medical counseling, 13% in psychiatric counseling, 2% in psychotherapy, 2% in family therapy and 6% in group therapy (Driessen, 1992).
In 1993-1994, the cohort of methadone clients interviewed in 1991 was again approached, to obtain information about the developments in their status after 2-2.5 years (Driessen et al., 1999). In the course of this follow-up period, nine of the original 599 subjects had died (1.5%), of whom one person due to a drug overdose, 8.4% was found to be abstinent (for at least three months), and by far the largest group (90.1%) was still using illicit drugs and/or methadone. From this latter group (of whom 96% had participated in a methadone maintenance program in the year before the follow-up interview), 32% was considered to be integrated, 61% not integrated, and 7% very problematic drug users (Driessen et al., 1999).
These early data (Driessen, 1990, 1992, 1999) are supported by a more recent study, conducted in Amsterdam (Buster and Van Brussel, 1996). This study found that 5,545 heroin addicts living in Amsterdam had received methadone between 1994 and 1995. Based on the results of urinalysis tests, 65-70% of them were found to still be using heroin regularly or even daily. This high level of illegal heroin use cannot be explained (as it sometimes has been) as a byproduct of low methadone dosages (less than 50 milligrams), however, because in 1995 in Amsterdam, the average daily methadone dose amounted to almost 60 milligrams (Van Brussel et al., 1996).
In addition to the 11,500 patients in methadone maintenance programs in 1995, there were more than 1,400 drug-related admissions to a general psychiatric hospital and more than 3,000 drug-related admissions to addiction treatment clinics in the Netherlands (Gageldonk et al., 1997). Finally, some outpatient drug-free treatment is provided by the Dutch Consultation Centers for Alcohol and Drugs. It should be noted that these numbers can not be simply added to obtain figures for the Netherlands as a whole, because some patients use more than one of the above services during the registration period and therefore could be counted more than once. It is, however, quite certain that the amount and the types of services, which are currently provided to heroin addicts, are very similar to those in 1988 (Driessen, 1990).
In 1993, the Netherlands Institute of Mental Health (NcGv) surveyed 1,900 patients and ex-patients from the Consultation Centers for Alcohol and Drugs (Jongerius et al., 1994). The results of this survey indicated that 62% of the methadone patients were (very) satisfied with the treatment they had received. Almost 60% reported a reduction in their heroin use as a result of this treatment, and nearly one third reported abstinence in terms of illicit drug use. Despite these positive outcomes, 47% of the patients reported that methadone had made it more difficult for them to achieve abstinence, and 10% reported that methadone treatment had not had any positive impact on them. These data are very similar to those collected earlier by Driessen (1992), in which 47% reported one or more major complaints, especially regarding dispensing times, the lack of take-home prescriptions and the undesired contact with other drug addicts.
In the Netherlands, there are many different regimes offered by methadone programs, but no data are available on the relationship between methadone dose-levels, the various forms of counseling provided in the programs, and the results of the treatment. However, data provided by the Amsterdam Municipal Health Service indicate that there has been an increase in the average daily methadone dosage from 43 milligrams in 1989 to 56 milligrams in 1995 (Van Brussel et al., 1996), and similar developments have been reported in other cities in the Netherlands (NDM, 2001). This average is, however, still lower than the recommended dose-level used in programs in the United States (Parrrino, 1992). According to the American guidelines, the effective daily methadone dosage should be about 80 milligrams plus or minus 20 milligrams. However, a national survey showed in the US indicated that many programs had dose limits below these effective ranges and that many programs applied time limits regarding the maximum length of stay allowed in the program (D'Aunno and Vaughn, 1992). Given the fact, that most patients who receive methadone in the Netherlands are either unable or unwilling to give up their heroin use, higher methadone doses, which would prevent them from experiencing the euphoric effects of heroin (Korf et al., 1998), are often unacceptable to the patient. Consequently, prescribing higher doses of methadone is likely to promote elevated drop-out rates, thereby undermining one of the main aims of the Dutch methadone treatment system - to reach as many addicts as possible for prevention, medical supervision and treatment.
The effectiveness of this pragmatic approach is evidenced, among other measures, by the relatively small proportion of injecting drug users who are AIDS patients in the Netherlands (12%) compared to the United States (24%) and Europe at large (38%) (Van Laar et al., 1995). In addition, deaths attributable to drug addiction (as a primary or secondary cause) of death remain quite low in the Netherlands, where only 33 drug-related deaths of Dutch residents were registered in 1995 (De Zwart and Van Wamel, 1998). In Amsterdam and Rotterdam, the cities with by far the largest population of heroin users and addicts, 16 and 14 deaths occurred respectively in 1996 (De Zwart and Van Wamel, 1998).

Taken together, these findings suggest that methadone maintenance treatment is widely available in the Netherlands. At least 50% of all heroin addicts are currently enrolled in one of these programs, which serve a stable and aging population of chronic heroin addicts with long addiction and treatment careers. It was also observed that a substantial number of the methadone patients regularly use illegal heroin and other illegal drugs. Approximately 8,000 of the 12,500 methadone maintenance patients function at less than optimal levels, exhibiting low levels of medical and psychosocial functioning, and about 3,000 of them are engaged in high levels of criminal behavior.
There has been a growing awareness of the limited success of the treatment efforts in these sub-populations, despite extensive attempts by professionals to improve the living conditions of these chronically addicted patients. In addition, there have been repeated calls for reductions in the public nuisance which results from their criminal behavior. These aspects have led to various attempts to prescribe opioids other than oral methadone for the treatment of chronic, and especially treatment-resistant heroin addicts in the Netherlands. These efforts are briefly discussed in the next paragraph.

(1) It should be noted that this estimate by Driessen (1990) is slightly lower than the estimate by Schroeder and Broex (1998) in paragraph 1.3.