Substance misuse in the psychiatric emergency service; a descriptive study

Abstract

Substance misuse is frequently encountered in the psychiatric emergency service (PES) and may take many forms, ranging from formal DSM-IV diagnoses to less obvious entities such as hazardous consumption. Detecting such patients using traditional screening instruments has proved problematic. We therefore undertook this study to more fully characterize substance misuse in the PES and to determine whether certain variables might help better screen these patients. We used a prospectively acquired database of over 18,000 visits made to four PESs during a 2-year period in the province of Quebec, Canada. One of the variables acquired was a subjective rating by the nursing staff as to whether substance misuse was a contributing factor to the visit (graded as direct, indirect, or not at all). Substance misuse accounted for 21% of all diagnoses and alcohol was the most frequent substance used. Patients were divided into those with primary (PSM), comorbid (CSM) or no substance misuse (NSM). Depressive disorders were the most frequent primary diagnoses in CSM, whereas personality and substance misuse disorders were frequent secondary diagnoses in PSM. Although many variables significantly differentiated the three groups, few were sufficiently detailed to be used as potential screening tools. Those situations that did have sufficient details included those with a previous history of substance misuse, substance misuse within 48 hours of the visit, and visits graded by the nursing staff as being directly and/or indirectly related to substance misuse. Variables related to substance misuse itself were the primary predictors of PSM and, less significantly, CSM. The nursing staff rating, although promising, was obtained in less than 30% of all visits, rendering its practical use difficult to assess.

Keywords: epidemiology; prospective study; psychiatric emergency service; substance misuse.

Figure 1

The relative contributions of the different substances to a primary or comorbid substance misuse diagnosis.¹ Notes: ¹P < 0.001, Pearson chi2 and likelihood-ratio.

Figure 2

The secondary diagnoses¹ of primary substance misuse and the primary diagnoses of comorbid substance misuse visits.² Notes: ¹AD (adjustment disorders), PER (personality disorders), DEP (major affective disorders), SCH (schizophrenia/chronic psychotic disorders), ANX (anxiety disorders), SM (substance misuse disorders), Other (all other DSM-IV disorders). ²P < 0.001, Pearson chi2 and likelihood-ratio.

Figure 3

Discharge recommendations¹ following the psychiatric assessment.² Notes: ¹Crisis center (both hospital-based and community-based), Outpatient (referred to the hospital outpatient service), Fam. physician (referred to their family physician), Day Hospital (referred to a hospital-based day hospital), Comm. care (social resources, intensive community follow-up, emergency housing or shelter), SM (substance misuse) resources (detoxification centers, both inpatient or outpatient), None (no specific recommendation was made), Other (refused treatment, left without being assessed, transfer to another emergency service, returned to the medical emergency service for further medical treatment). ²Assessed in a total of 8,073 visits. P < 0.001, Pearson chi2 and likelihood-ratio.

Figure 4

The age distribution of visits tagged as being without, with primary or with comorbid substance misuse.