Researchers have long known the efficacy of psychological treatment to reduce violent offending by adult and juvenile offenders. An interesting US study suggests that ‘too little’ treatment may be worse than no treatment at all.
The researchers use an ingenious natural experiment design to investigate the efficacy of ‘strong dose’ vs ‘weak dose’ treatments. In this context, ‘dose’ refers to duration of treatment (typically measured in months), and intensity (typically measured in number of treatment sessions per week).
The study follows up 400 violent offenders who were incarcerated in juvenile treatment facilities in a southern US state between 1987 and 2007. Some received a strong treatment dose, i.e. more than 4.5 months of treatment, and others received a low dose, i.e. less than 4.5 months of treatment. The recidivism measure was the number of convictions within three years of release. All were the most serious/violent offenders in the state.
This natural experiment allowed for comparison of offenders who received a ‘strong’ dose vs a ‘weak’ dose vs ‘no’ treatment.
Treatment involved 2-3 sessions per week which were run by qualified staff, e.g. registered psychologists etc. Each session was four hours long and could be broadly categorised as ‘cognitive behaviour therapy’.
The study shows, inter alia, that a strong treatment dose results in a 54.4% recidivism rate whilst a weak does results in 69.5% rate. No real surprise in this result. What was surprising is that those who received a weak dose were more likely to recidivate than those who received no treatment at all. This result, whilst interesting, needs to be treated with caution.
The study can be criticised on methodological grounds. The researcher uses complex statistical techniques to demonstrate that the ‘strong’ dose group was the same as the ‘weak’ does group in terms of previous offending, severity of offending, gang membership and trauma background. Therefore it is implied that the causal mechanism of increased offending was the low treatment dose.
Take outs for practitioners and policy makers:
- Treatment reduces violent offending
- The most violent offenders should be afforded the most intensive treatment in terms of duration, intensity and delivery by qualified staff.
Haerle, D. R. (2016). “Dosage Matters: Impact of a Violent Offender Treatment Program on Juvenile Recidivism.” Youth Violence and Juvenile Justice 14(1): 3-25.