Marijuana Screening

INTRODUCTION

Similar to the screens developed for alcohol there is a need to develop screening inventory for marijuana due to the widespread use of marijuana. Marijuana use poses unique assessment dilemmas for medical and mental health generalists. Clinically assessing whether marijuana use is a problem or not can be challenging in a context of confusing messages. A marijuana-specific screening inventory may help guide clinicians through the confusion around clinical assessment of marijuana use. This article describes the development and initial psychometric properties of the Marijuana Screening Inventory--Experimental Version (MSI-X). A reliable and valid MSI-X may assist clinicians in screening clients to determine if their marijuana use pattern places them "at risk" and merits more intensive evaluation. Multiple reasons support the need for developing a marijuana-specific screening inventory.

Prevalence Data Support Marijuana-Specific Screening

National prevalence data regarding marijuana use support the need for a marijuana-specific self-report screen. Marijuana, despite its illegality, continues to be the most common and widely used illicit drug in the United States. National surveys of illicit drug abuse suggest lifetime adjusted prevalence rates for marijuana use increased in the last 25 years from 53% to 78% for those between ages 19 and 40. The majority of those using illicit drugs use only marijuana. Past-year marijuana use ranged from 37% to 14% among 19 to 40 year olds. Among the 14 million Americans using illicit drugs in a past month, 59% consumed only marijuana, 17% marijuana with other drugs, and 24% used an illicit drug other than marijuana. Because alcohol-specific screening inventories exist for assessing the 47% to 64% of current alcohol drinkers, it is surprising that similar marijuana specific screens have not been developed for assessing the 37% of past-year marijuana users.

Culturally Confusing Messages and Screening

Assessment dilemmas also emanate from culturally confusing messages about marijuana risks. Cultural, legal, and scientific controversy swirls around the innocuousness, risks, or benefits of marijuana use and confuses public and professional perceptions. These mixed messages complicate marijuana assessment. Pop culture reverberates with messages that marijuana use, even frequent use, is innocuous and acceptable. Efforts to legalize marijuana, especially for medicinal purposes, further clouds the marijuana risks issue. Decriminalization of personal marijuana use in many European countries raises benchmark questions regarding our own laws.

Continuing scientific and clinical debate among health care professionals about harmful or nonharmful aspects of marijuana use complicates assessment. Reviews providing scientifically balanced information on the benefits and risks of marijuana use still leave the public and many clinicians uncertain regarding marijuana risks. It's not surprising that questions of bow to accurately screen and assess for problematic marijuana use may become confused within this context.

Clinical Assessment Dilemmas and Screening

Clients and clinicians arrive at clinical encounters confused about what constitutes a marijuana use problem. Clients rarely mention marijuana as a primary or secondary problem. Clinicians may not know when or how to assess for, or recognize, marijuana use problems. Clinical assessment dilemmas flow from other areas. First, marijuana quantity and frequency clinical risk guidelines are not clear, adding to the general conceptual confusion regarding what constitutes a problem marijuana use pattern. Second, DSM IV-TR criterion for abuse and dependence may be unclear when applied to marijuana. Third, lab tests and general drug questionnaires are inadequate to assess marijuana use patterns. How these issues complicate marijuana assessment merit further explanation.

Many citizens use marijuana, but sorting out who does so at a quantity and frequency level defined as problematic is clinically more challenging. Quantity and frequency guidelines specific to marijuana use are not clearly established as they are for alcohol. Marijuana dose level variations complicate quantity and frequency assessment. Separate criteria measures are not clearly defined for marijuana quantity and frequency, for what constitutes "experimental," "frequent," or "heavy" marijuana use and such constructs are not clearly correlated with negative outcomes.

General criticism exists regarding DSM statistical validity and reliability. Clinician differences in replicating DSM diagnoses may amplify when applying DSM IV-TR criteria to cannabis dependence and abuse. The DSM-IV-TR states: "There are NO unique criteria sets for Cannabis Dependence or Abuse," and "cannabis Withdrawal is not included". Questions remain whether cannabis "dependence" is psychological only or whether valid "withdrawal" phenomena exist. Subjective clinical judgment enters into Cannabis Abuse criterion distinctions regarding the meaning of "recurrent" or "maladaptive pattern". For example, legal consequence risks are present with any marijuana use level, but may remain latent, or risk exposure only if the person drives or buys. Regarding the "legal" or "driving" problems with marijuana to allow steady clinical agreement that a "recurrent" "maladaptive pattern" exists as behavioral frequency cutoffs are not suitably obvious.