In previous studies Lloyd et al found that people with a history of hypomanic experiences reported more gambling problems online,11 and that their gambling was driven by the desire to experience enjoyment and to regulate mood.12 The major finding presented here is that people with a diagnosis of type 2 bipolar disorder were at significantly higher risk of gambling problems than those with a diagnosis of type 1 disorder. The characteristic feature of type 2 bipolar disorder is the presence of hypomanic rather than manic symptoms and an absence of the psychotic symptoms often observed in type 1 disorder.13,17 Therefore, these data suggest that the characteristics of mild mood elevation involving enhanced reward focus, sleeplessness and distractibility constitute particular risk factors for problematic use of gambling services. In addition, our finding that a quarter of patients with gambling problems reported that more than half of their gambling in the past 12 months had involved the internet highlights the potential for gambling-related harm in people with bipolar disorder using internet gambling services that are available 24 h a day through fast-developing technologies.18
