Depression is a highly recurrent disorder with significant personal and public health consequences. Prevention of recurrence would be extremely desirable, and thus researchers have begun to identify risk factors that are specific to recurrence, which may be different from risk factors for first-onset of depression. Methodological issues in this area of research are briefly reviewed (e.g., the various definitions of "recurrence" and "depression"), followed by a review of studies on specific risk factors, including demographic variables (gender, socio-economic status, marital status), clinical variables (age at first onset, number of prior episodes, severity of first/index episode, comorbid psychopathology), family history of psychopathology, and psychosocial and psychological variables (level of psychosocial functioning, cognitions, personality, social support, and stressful life events). In addition, scar theories are evaluated for their potential to explain how these variables and recurrent depression are linked. Our review suggests that recurrent depression reflects an underlying vulnerability that is largely genetic in nature and that may predispose those high in the vulnerability not only to recurrent depressive episodes, but also to the significant psychosocial risk factors that often accompany recurrent depression.Major depressive disorder is one of the most common forms of psychopathology, one that will affect approximately one in six men and one in four women in their lifetimes . It is also usually highly recurrent, with at least 50% of those who recover from a first episode of depression having one or more additional episodes in their lifetime, and approximately 80% of those with a history of two episodes having another recurrence (American Psychiatric Association, 2000;Kupfer, Frank, & Wamhoff, 1996;Post, 1992). Once a first episode has occurred, recurrent episodes will usually begin within five years of the initial episode (Belsher & Costello, 1988;Lewinsohn, Clarke, Seeley, & Rohde, 1994), and, on average, individuals with a history of depression will have five (Kessler & Walters, 1998) to nine (Kessler, Zhao, Blazer, & Swartz, 1997) separate depressive episodes in their lifetime.Due to the fact that depression can be so recurrent, it can have significant personal and public health consequences. For example, one meta-analysis found that the suicide rate among those with depression is approximately twenty times higher than the rate for the general population (Harris & Barraclough, 1997). In addition, a study of over 3000 adolescents and young adults found that 90% of those with recurrent depression reported "very much" impairment, limiting work productivity and social interactions, and 40% sought professional help as a result (Wittchen, Nelson, & Lachner, 1998). Depression can also have a significant economic impact due to decreased productivity in affected individuals (Klerman & Weissman, 1992); in 1996 the annual direct (e.g., visits to doctors, pharmaceutical costs) and indirect (e.g., time...
