Antisocial personality disorder (ASPD) is a common adult psychiatric disorder characterized by low self-control, lack of empathy, disregard for others, and high levels of impulsivity and aggression. Many studies have shown that ASPD is one of the most common co-occurring disorders in patients with drug addiction and is a predictor of many drug addictions. For example, among heroin addicts who have a high prevalence of ASPD, factors such as education, age at first drug use, withdrawal time, and daily dose are predictors of ASPD. However, the prevalence and clinical correlates of ASPD among methamphetamine (MA) patients are unknown.

To address this issue, Prof. ZHANG Xiangyang's group from the Institute of Psychology of the Chinese Academy of Sciences (CAS) recruited 627 male MA patients to assess the prevalence and correlates of ASPD among MA patients.

Subjects recruited were MA patients over 18 years old who do not use other drugs in combination, met the diagnostic criteria based on the Chinese version of the the Diagnostic and Statistical Manual of Mental Disorders-V (DSM-5), are not color blind, have no major medical conditions and have more than 6 years of education.

The researchers used a cross-sectional design to collect the demographic information of the subjects. Information such as age, education level, substance use history, medical and psychological status and Body Mass Index (BMI) was collected by one-to-one questioning.

The researchers then used the Mini International Neuropsychiatric Interview, a brief structured diagnostic interview to identify patients with ASPD. Two questionnaires were used to measure direct drug craving. The Drug Craving Questionnaire (DDQ) has three factors: desire and intention, negative reinforcement and control. The Visual Analogue Scale (VAS) was a pain rating scale based on the self-report symptom measures.

As the data were non-normal, the Kruskal-Wallis H nonparametric test and binary stepwise logistic regression analysis were used for statistical analysis.

Results of the study showed that the prevalence of ASPD among Chinese male MA patients was 27.59%. Compared with non-ASPD subjects, patients with ASPD were younger at first drug use, had a longer period of abstinence and use, and had higher drug cravings and intentions, negative reinforcement, total DDQ scores, and VAS.

Further logistic regression analysis revealed that age, age at first drug use, time to abstinence and negative reinforcement scores were factors associated with ASPD in MA patients.

These findings remind us that we should pay attention to MA patients with ASPD earlier and provide early treatment and intervention whenever possible.

This study was supported by the National Program on Brain Science and Brain-like Intelligence Technology of China, the National Natural Science Foundation of China, the International Partnership Program of CAS, among others.