Depression, anxiety and comorbid substance use: association patterns in outpatient addictions treatment

Abstract

Depression and anxiety disorders commonly coexist with drug and alcohol use. Several general population surveys suggest non-linear associations between alcohol and depression symptoms. It is unclear whether such association patterns occur in clinical samples and in the context of poly-substance use. The aim of the study was to investigate the association patterns between substance use and common mental disorder (CMD) severity. Patients accessing a UK outpatient addictions service were recruited sequentially via routine treatment contacts. Psychiatric diagnosis and severity of symptoms were established using the revised clinical interview schedule (CIS-R) structured diagnostic interview; yielding WHO ICD-10 diagnoses for CMD. Data on substance use patterns in the last month and severity of dependence were collected using standardised measures. ANOVA and multivariate regression models were employed to investigate associations between CMD symptom severity and substance use patterns. The results of the multivariate regression analyses indicated a linear association between weekly alcohol use and CIS-R severity; this was statistically significant when adjusting for severity of dependence, poly-substance use, gender and age. Other drug use patterns were not directly associated with overall psychiatric symptom scores, but some evidence was found that specific patterns of drug use correlate with specific psychological symptoms. In conclusion, only alcohol use was significantly associated with psychiatric symptom severity in the context of poly-substance use. Contrary to epidemiological surveys in the general population, no evidence was found for nonlinear associations between CMD and substance use in this clinical sample; nor did we find evidence that recent abstinence increases symptom severity.

Disentangling psychopathology, substance use and dependence: a factor analysis

“…This study presents a detailed examination of symptom-level associations between common mental disorders (CMD), substance use and severity of dependence. To our knowledge, such analyses are rare [ 26 ], and offer novel information to validate theories about comorbidity and psychopathological processes. Consistent with the wider literature cited above, we found significant and moderate correlations between psychopathology and severity of dependence in a clinical sample of drug and alcohol users, although these were distinct and separate dimensions.…”

“…Furthermore, most studies in this area examine associations at the level of syndromes or disorders, which could possibly mask specific symptom-level relationships and could also introduce artificial relationships because of double counting of symptoms [ 25 ]. For instance, in a recent study, severity of dependence has been found to correlate with several symptoms of depression and anxiety, whereas only few CMD symptoms were correlated with level of substance use and abstainers were just as likely to have a CMD diagnosis compared to users [ 26 ]. Symptom-level associations such as these have rarely been examined, and until such studies proliferate the debate about causal links will probably continue unabated.…”

A study of the psychotropic prescriptions of people attending an addiction service in England

“…Earlier studies in the USA have also found this frequent co‐occurrence (Kessler et al , 1996; Regier et al , 1990). In clinical populations, the reported prevalence of mood and anxiety disorders among people with SUD is much higher with UK studies showing frequencies of 70 per cent and above (Delgadillo et al , 2012; Weaver et al , 2003). However, the high prevalence of these mental disorders among people with SUD has been a subject of debate due to problems inherent in distinguishing independent mental disorders from substance‐induced mental disorders and the resulting implications on treatment strategies (Schuckit, 2006; O’Brien and Charney, 2004).…”

Multiple obstacles to psychological care from the viewpoint of addiction service users

“…For example, in a multi-national general population survey, approximately 26 per cent of alcohol-dependent and 35 per cent of drug-dependent cases were diagnosed with comorbid affective/mood disorders (Merikangas et al, 1998). The prevalence of mild through to severe depression cases in clinical samples of substance users is thought to be as high as 40-49 per cent (Delgadillo et al, 2013;Weaver et al, 2003).…”