ASSESSMENT OF SUBSTANCE ABUSE: DRUG ABUSE SCREENING TEST (DAST)

The assessment of drug use and related problems is important for both prevention and clinical care. Measures that are both reliable and valid provide tools for health education, for identifying problems (early if possible) in health care and community settings, and for evaluating the effectiveness of treatment. As well, this information is useful for matching individual needs and readiness for change with tailored interventions.

The Drug Abuse Screening Test (DAST) was designed to be used in a variety of settings to provide a quick index of drug-related problems. The DAST yields a quantitative index of the degree of consequences related to drug abuse. This instrument takes approximately 5 minutes to administer and may be given in questionnaire, interview, or computerized formats. The DAST provides a brief, self-report instrument for population screening, identifying drug problems in clinical settings and treatment evaluation.

DAST-20 and DAST-10 Versions.

The DAST was modeled after the widely used Michigan Alcoholism Screening Test (Selzer, 1971). Measurement properties of the DAST were initially evaluated using a clinical sample of 256 drug-alcohol-abuse clients (Skinner, 1982). The 20-item DAST has excellent internal consistency reliability (alpha) at 0.95 for total sample and 0.86 for the drug-abuse sample. Good discrimination is evident among clients classified by their reason for seeking treatment. Most clients with alcohol-related problems scored 5 or below, whereas the majority of clients with drug problems scored 6 or above on the 20-item DAST. The DAST-10 correlates very highly (r = 0.98) with the longer DAST-20 and has high internal consistency reliability for a brief scale (0.92 for the total sample and 0.74 for the drug-abuse sample).

Subsequent research has evaluated the DAST with various populations and settings including psychiatric patients (Cocco & Carey, 1998; Maisto et al., 2000; Staley & El Guebaly, 1990), prison inmates (Peters et al., 2000), substance-abuse patients (Gavin et al., 1989), primary care (Maly, 1993), in the workplace (El-Bassel et al., 1997), and adapted for use with adolescents (Martino et al., 2000). Overall, these studies support the reliability and diagnostic validity of the DAST in diverse contexts.

Advantages.

1. The DAST is brief and inexpensive to administer. Versions are being developed in different languages (French and Spanish).
2. It provides a quantitative index of the extent of problems related to drug abuse. Thus, one may move beyond the identification of a drug problem and obtain a reliable estimate of the degree of problem severity.
3. The DAST has been evaluated and demonstrated excellent reliability and diagnostic validity in a variety of populations and settings.
4. Routine administration of the DAST would provide a convenient way of recording the extent of problems associated with drug abuse, ensuring that relevant questions are asked of all clients/patients.
5. The DAST can provide a reference standard for monitoring changes in the population over time, as well as for comparing individuals in different settings.

Limitations.

1. Since the content of the DAST items is obvious, individuals may fake results.
2. Since any given assessment approach provides an incomplete picture, there is a danger that DAST scores may be given too much emphasis. Because the DAST yields a numerical score, this score may be misinterpreted.

Administration, Scoring and Interpretation.

The DAST may be administered in a questionnaire, interview, or computerized format. The questionnaire version allows the efficient assessment of large groups. The DAST should not be administered to individuals who are presently under the influence of drugs, or who are undergoing drug withdrawal. Under these conditions the reliability and validity of the DAST would be suspect. Respondents are instructed that "drug abuse" refers to (1) the use of prescribed or over-the-counter drugs in excess of the directions and (2) any non-medical use of drugs. The various classes of drugs may include cannabis, (e.g., marijuana, hash), solvents or glue, tranquillizers (e.g., valium), barbiturates, cocaine, stimulants, hallucinogens (e.g., LSD), or narcotics (e.g., heroin). Remember that the questions do not refer to the use of alcoholic beverages.

The DAST total score is computed by summing all items that are endorsed in the direction of increased drug problems. Guidelines for interpreting DAST scores and recommended action are given in Table 1. A score of 3 or more on the DAST-10 and 6 or more on the Dast-20 indicates the likelihood of substance abuse or dependence (e.g., DSM IV, American Psychiatric Association). This diagnosis would need to be established by conducting a further diagnostic assessment.

Availability. Copies of the DAST may be obtained from H. Skinner, (E-mail: [email protected]), or from the Centre for Addiction and Mental Health, 33 Russell Street, Toronto, Ontario, Canada M5S 1A8, telephone: 1-800-463-6273 (http://www.camh.net). A computerized version of the DAST is included in the Computerized Lifestyle Assessment (Skinner, 1994) published by Multi-Health Systems, Toronto (http//www.mhs.com); call 1-800-268-6011 in Canada or1-800-456-3003 in the United States.

BIBLIOGRAPHY

Cocco, K. M. and Carey, K. B. (1998). Psychometric properties of the Drug Abuse Screening Test in psychiatric outpatients. Psychological Assessment, 10, 408-414.

El-Bassel, N., Schilling, R. F., Schinke, S., et al. (1997). Assessing the utility of the Drug Abuse Screening Test in the workplace. Research on Social Work Practice, 7, 99-114

Gavin, D. R., Ross, H. E., and Skinner, H. A. (1989). Diagnostic validity of the DAST in the assessment of DSM-III drug disorders. British Journal of Addiction, 84, 301-307.

Maisto, S. A., Carey, M. P. and Carey, K. B., et al. (2000). Use of the Audit and the DAST-10 to identify alcohol and drug use disorders among adults with a severe and persistent mental illness. Psychological Assessment, 12, 186-192.

Maly, R. C. (1993). Early recognition of chemical dependence. Primary Care, 20, 33-50.

Martino, S., Grilo, C. M. and Fehon, D. C. (2000). Development of the Drug Abuse Screening Test for adolescents (DAST-A). Addictive Behaviors, 25, 57-70.

Peters, R. H., Greenbaum, P. E., Steinberg, M. L., et al. (2000). Effectiveness of screening instruments in detecting substance use disorders among prisoners. Journal of Substance Abuse Treatment, 18, 349-358.

Skinner, H. A. (1982). The Drug Abuse Screening Test. Addictive Behaviors, 7, 363-371.

Skinner, H. A. (1994). Computerized lifestyle assessment manual. Toronto: Multi-Health Systems.

Staley, D., and El Guebaly, N. (1990). Psychometric properties of the Drug Abuse Screening Test in a psychiatric patient population. Addictive Behaviors, 15, 257-264.

Harvey A. Skinner