With individuals who have anxiety disorders, panic attacks tend to occur in specific situations, but may also occur in supposedly safe situations. However, with most panic attacks, and especially those associated with panic disorders these panic attacks are not caused by a specific precipitating stimulus, but rather occur without a specific stimulus.

Individuals who experience panic attacks (who will be subsequently referred to as Panickers) tend to have a variety of affective differences when compared to those who have not experienced panic attacks (referred to below as Non-panickers). For example, panickers tend to be more depressed as compared to non-panickers (Barlow, et al. 1984; Beiser & Fleming, 1986; Breier, Charney & Heninger, 1986; Broyles, 1987; Chambless, 1985; Chambless, Caputo, Bright & Gallager, 1984; Katon, et al., 1986; Murray, 1987; Norton, et al., 1986; Norton, et al., 1985).

Norton et al. (1986) examined the relationship between panic attacks and depression. The participants were a non-clinical sample of young adults attending evening classes at a public university. Those individuals who had experienced panic attacks were significantly more depressed than non-panickers. Using a clinical sample, Chambless (1985) found similar results. A positive relationship between the Beck Depression Inventory (Beck, 1978) and panic intensity and frequency were found. Broyles (1987) compared clinical subjects with and without panic attacks. Panickers were significantly more depressed than non-panickers. Thus it would appear that individuals who experience panic attacks tend to be more depressed than subjects without panic attacks.