RESULTS
Table 1 presents the retabulated data from all three studies. It is important to note that the rates of MDD (primary plus secondary) among relatives of probands with MDD without anxiety (MDD), panic disorder with or without depression (PD ± MDD), and agoraphobia with or without depression (Ag/PD ± MDD) were not significantly different from each other and all were significantly greater than the rate observed among relatives of controls (Table 2). The rate of MDD among relatives of MDD probands with chronologically secondary panic disorder (MDD + PD) was higher than the rates of MDD among relatives of other types of probands. The rate of MDD among relatives of panic disorder and agoraphobic probands could be lower because of the fact that it represents an average rate from families of panic disorder and/or agoraphobic probands with and without depression. It is important to note that the rates of MDD among relatives of MDD probands with or without panic (MDD ± PD) is not significantly elevated when compared to the rates of MDD among relatives of PD ± MDD and Ag/ PD ± MDD probands. If the pattern is similar to that observed among relatives of MDD probands, then there could be a significantly elevated rate among relatives of anxious probands with chronologically secondary depression when compared to the rates among relatives of anxious-only probands. Unfortunately, the published data do not allow the separation of anxious probands into those groups. Nevertheless, these results demonstrate that when overall rates of diagnoses 
are tabulated without regard to the primary/secondary distinction, the frequency of depression among relatives of panic disorder and agoraphobic probands is significantly elevated when compared to relatives of control probands and is the same as the rate of MDD among relatives of probands with MDD and no anxiety. This suggests that there may be some familial association between the two disorders. However, additional analyses, not possible with these published data, are necessary to understand more clearly this possible relationship. The frequency of anxiety diagnoses is also significantly elevated among relatives of ill probands regardless of diagnosis. However, the rates are much higher when the diagnosis of the proband is either panic disorder or agoraphobia. It remains to be seen if the rates of anxiety are dependent on whether the proband has an additional diagnosis of MDD.