Toward patient-tailored therapy in agonist opioid treatment: The role of psychopathology, craving behavioural covariates, stress reaction and methadone blood concentration. A case series

Background: A patient-tailored therapeutic approach in the field of Heroin Use Disorder (HUD) still seems to be in its infancy. The study of patients' specific psychopathology, craving behaviours and stress reactivity pointed to novel information in making treatment choices and improving outcomes. Indeed, biological features appear to be scarce. Methods: We enriched the standard assessment procedure by adding the study of psychopathology, craving behaviours and stress reactivity changes during treatment. After 6 months of methadone treatment (during the maintenance phase) 10 patients were asked to fill in the same questionnaires once more, and they performed a blood withdrawal using dried blood spot methodology to check for blood methadone levels. Results: All patients displayed clinical improvement after entering treatment, without relevant side effects. Despite this, 4 of them continued to use heroin and cocaine in the next six months. The psychopathological symptoms showed a significant reduction in severity, and the typology was relatively stable over time. Craving behaviours exhibited a general improvement, but not in the specific case of risk behaviours. In contrast, stress reactivity tended to worsen. Both a positive correlation between dried blood spot methadone level, and differences in the psychopathology and severity of behavioural craving were ascertained. No correlation, however, was detected between differences in stress reactivity and methadone blood spot level concentration. Conclusions: This case series suggests that, in the HUD field, clinicians should take advantage of information deriving from correlations between patients' clinical and biochemical characteristics to permit a better personalization of diagnostic and therapeutic interventions. Craving behavioural covariates, 5-factor psychopathological dimensions, stress reaction and the monitoring of dried blood spot methadone concentration should be proposed as parameters to be used in patient-tailored therapy.