Aims: This study aimed to validate the presence of a khat use disorder syndrome using DSM-5 criteria and to examine its relationship with increased experience of harms.

Design: Cross-sectional, purposive sample of current khat-chewers, recruited from khat markets and cafes.

Setting: Participants were recruited from the general community and from Adama Science and Technology University in Ethiopia.

Participants: A total of 400 current khat consumers aged 16 and above were recruited between September 2014 and January 2015.

Measures: Survey comprising current clinical symptoms (using a modified Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV), and validated measures of health, psychological distress, quality of life and academic functioning.

Findings: A third [35.5% 95% confidence interval (CI) = 31.0-40.3] of respondents reported daily khat use and a quarter (25.4% 95% CI = 21.4-30.0) using three times or more per week. Using DSM-5 criteria, 10.5% (95% CI = 7.9-13.9) were categorized as experiencing mild, 8.8% (95% CI = 6.4-12.0) moderate and 54.5% (95% CI = 49.6-59.3) severe khat use disorder. Confirmatory factor analysis demonstrated a good fit of symptoms to a single underlying construct, consistent with other substance use disorders. Individuals categorized as experiencing khat use disorder demonstrated significantly greater frequency [odds ratio (OR) = 45.29; 95% CI = 10.97-19.01) and quantity of khat use (OR = 2.35; 95% CI = 1.29-4.29). They also demonstrated increased financial problems associated with use, greater problems with academic functioning and higher rates of self-reported mental health problems, higher psychological distress and poorer quality of life. Treatment access was poor, with only one-third (32.9%) of individuals with khat use disorder reporting life-time access, near-exclusively related to help-seeking from friends and relatives.

Conclusion: The construct of a substance use disorder syndrome for khat using DSM-5 criteria appears valid and performs in a manner consistent with other substances of dependence. Individuals with khat use disorder experience substantial problems in association with khat use. Despite this, there are low levels of help-seeking for these problems.