Abstract
Objective: By comparing the co-occurring symptoms instead of co-occurring diagnoses, we will determine if there are symptoms independent of DSM diagnoses that are capable of differentiating between pathological gamblers (PG) and non-pathological gamblers. Method: This study identified past 12-month co-occurring sub-diagnostic psychiatric symptoms (i.e. shadow symptoms) among the 43,093 individuals who participated in the National Epidemiological Survey on Alcohol and Related Conditions. We compared the prevalence of these shadow symptoms among individuals with five or more DSM-IV (PG) symptoms to the prevalence among individuals who gamble with no associated problems. Factor analyses applied to 428 non-duplicated past-year symptoms compiled from 29 DSM-IV diagnostic schedules yielded 13 symptom clusters that included 212 symptoms. Results: Most (58%) PGs reported symptoms that were not directly related to gambling, but were more prevalent among gamblers without gambling-related problems. Conclusions: These findings provide evidence that people who satisfy DSM-IV diagnostic criteria (e.g. pathological gambling) are likely to report meaningful co-occurring sub-clinical symptoms that are associated with other diagnostic classes. Consequently, diagnostic classification should be complemented with an awareness of co-occurring sub-clinical symptom patterns (i.e. shadow syndromes).