The mere concurrence of illicit drug use and crime is not enough to conclude that illicit drug causes crime. According to qualitative research based in the European Union (EMCDDA - QED) there is little evidence of crime consequences from the vast recreational drugs scene across Europe. Alternatively there is an almost universally identified connection between "hard" dependent drug use, poverty, prostitution and crime.
Prison generally does not have a rehabilitative effect. Prisons may exacerbate harm caused by drug use - this harm may then be spread to the community outside prisons. There is also an adverse impact of arrest and imprisonment on employment, that fact increases the later involvement in crime. Owing to these and other pressures, interventions have been suggested and developed as a more effective way of working with problem drug users who commit crimes.
There is some evidence that law-enforcement measures as an alternative to prison for drug users offenders have a positive impact in reducing or mitigating crime. A panoply of diversion measures exist ranging from the informal and discretional powers of individual police officers to those based on discretionary power of magistrates and judges. The objectives of alternatives to prison vary but basically two can be identified: (a) to reduce criminal justice costs as well criminogenic effect in the case of minor offences; (b) to coerce severe drug addictsinvolved in crime to undertake appropriate treatment.
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