Validation of the Marijuana Effect Expectancy Questionnaire-Brief.

Area of Science:

• Psychology
• Substance Abuse Research
• Adolescent Health

Background:

• Understanding adolescent marijuana use is critical.
• Expectancy measures inform prevention and intervention strategies.
• The original Marijuana Effect Expectancy Questionnaire (MEEQ) is lengthy.

Purpose of the Study:

• To evaluate a brief version of the MEEQ (MEEQ-B).
• To assess the psychometric properties of the MEEQ-B.
• To determine its utility in clinical settings for youth.

Main Methods:

• The original MEEQ was reduced to a 6-item scale (MEEQ-B).
• Principal component analysis (PCA) was used to identify underlying factors.
• Internal consistencies and correlations with criterion variables were examined.

Main Results:

• PCA revealed two factors: positive and negative effects, explaining 52.3% of the variance.
• Internal consistencies ranged from 0.42 to 0.60, slightly lower than the original MEEQ.
• The negative effect expectancy scale showed significant correlation with marijuana use indicators (p ≤ .05).

Conclusions:

• The MEEQ-B is a potentially useful tool for clinicians assessing youth marijuana expectancies.
• The measure's brevity enhances its clinical applicability.
• Replication in diverse samples of adjudicated youth is recommended for further validation.