Chronology of illness in dual diagnosis heroin addicts: The role of mood disorders.

Background: Recent celebrity deaths have been widely reported in the media and turned the public attention to the coexistence of mood, psychiatric and substance-abuse disorders. These tragic and untimely deaths motivated us to examine the scientific and clinical data, including our own work in this area. The self-medication hypothesis states that individuals with psychiatric illness tend to use heroin to alleviate their symptoms. This study examined the correlations between heroin use, mood and psychiatric disorders, and their chronology in the context of dual diagnosis.

Methods: Out of 506 dual diagnosed heroin addicts, 362 patients were implicated in heroin abuse with an onset of at least one year prior to the associated mental disorder (HER-PR), and 144 patients were diagnosed of mental illness at least one year prior to the associated onset of heroin use disorder (MI-PR). The retrospective cross-sectional analysis of the two groups compared their demographic, clinical and diagnostic characteristics at univariate and multivariate levels.

Results: Dual diagnosis heroin addicts whose heroin dependences existed one year prior to their diagnoses (HER-PR) reported more frequent somatic comorbidity (p≤0.001), less major problems at work (p=0.003), more legal problems (p=0.004) and more failed treatment for their heroin dependence (p<0.001) in the past. More than 2/3 reached the third stage of heroin addiction (p=<0.001). Their length of dependence was longer (p=0.004). HER-PR patients were diagnosed more frequently as affected by mood disorders and less frequently as affected by psychosis (p=0.004). At the multivariate level, HER-PR patients were characterized by having reached stage 3 of heroin dependence (OR=2.45), diagnosis of mood disorder (OR=2.25), unsuccessful treatment (OR=2.07) and low education (OR=1.79).

Limitations: The main limitation is its retrospective nature. Nonetheless, it does shed light on what needs to be done from a clinical and public health perspective and especially prevention.

Conclusions: The data emerging from this study, does not allow us to determine a causal relation between heroin use and mental illness onset. However, this data, even if requiring longitudinal studies, suggest that self-medication theory, in these patients, can be applied only for chronic psychoses, but should not be applied to patients with mood disorders using heroin.