The Gambling Disorder Test (GDT)

The Gambling Disorder Test (GDT) (Pontes et al., 2025) is a brief standardized psychometric test designed to assess Gambling Disorder (GD code: 6C50) according to the most recent WHO diagnostic framework proposed in the ICD-11.

The development of the GDT marks a significant shift in how GD is assessed in light of recent scientific developments. This is because most research on GD utilizes popular assessment tools that are highly problematic, such as the Problem Gambling Severity Index (PGSI) (Ferris & Wynne, 2001), which does not reflect the current clinical and theoretical understanding of GD. Specifically, the PGSI was developed over 20 years ago based on the DSM-IV which did not consider GD a behavioral addiction but an impulse-control disorder instead.

Additionally, the PGSI was developed in reference to the South Oaks Gambling Screen (SOGS) (Lesieur & Blume, 1987) which has its own significant limitations. More specifically, the SOGS was developed based on the DSM-III and has been reported to produce high rates of false-positive diagnosis, overestimating the true number of affected individuals in the general population (Stinchfield, 2002).

To overcome these issues, the GDT was developed based on data from a large, nationally representative sample of adults from the United Kingdom. The overall development process ensured that the final items were directly aligned with the four core diagnostic features of GD as defined by the WHO, emphasizing its clinical relevance, as well as diagnostic, and conceptual alignment. The GDT is a brief and cost-effective tool that can be freely used by clinicians to assist in the clinical assessment of GD and by researchers conducting research on GD.

In the original psychometric development and validation study published in the prestigious refereed journal Psychological Assessment, the GDT has shown excellent psychometric properties in terms of:

• Construct validity: (i) factorial validity; (ii) population cross-validity, and (iii) concurrent validity.

• Internal consistency: (i) Cronbach’s alpha; (ii) McDonald’s Omega; (iii) Composite Reliability; and (iv) Factor Determinacy.

• Measurement invariance: (i) Gender invariance (full scalar).

It is important to note that further research, including, but not limited to, longitudinal and cross-cultural designs, are necessary to expand the initial validation findings reported. At present, the GDT is available in the following languages:

• English 🇬🇧: Download here