Examined the factor structure of the Hospital Anxiety and Depression Scale (HAD) using data from 624 male vs female Swedish adults (aged 30-39 vs 40-49 vs 50-59 yrs), and compared the HAD with the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI). A secondary aim was to examine the factor structure of the HAD. Results indicate that the factor structure was quite strong, consistently showing 2 factors in the whole sample as well as in the different subsamples. The correlations between the total HAD scale and the BDI and the STAI, respectively, were stronger than those obtained using the different subscales of the HAD (the anxiety and depression subscales). As expected, there was also a stronger correlation between the HAD and the nonphysical items of the BDI. It was somewhat surprising that the factor analyses were consistently extracting 2 factors, "depression" and "anxiety", while on the other hand both the BDI and the STAI tended to correlate more strongly with the total HAD score than with the specific depression and anxiety HAD subscales. Nevertheless, the HAD appeared to be a useful clinical indicator of the possibility of depression and clinical anxiety.