Depression is a highly recurrent disorder with significant personal and public health consequences. Researchers have begun to identify risk factors specific to recurrence, which may differ from those for first-onset depression. Methodological issues, including definitions of "recurrence" and "depression," are reviewed, 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). Scar theories are evaluated for their potential to explain how these variables and recurrent depression are linked. The review suggests that recurrent depression reflects an underlying genetic vulnerability that predisposes individuals to recurrent episodes and significant psychosocial risk factors. Major depressive disorder is common, affecting one in six men and one in four women. It is highly recurrent, with 50% of those recovering from a first episode having additional episodes, and 80% of those with two episodes having another recurrence. Recurrent episodes typically begin within five years of the initial episode, with individuals having five to nine episodes in their lifetime. Depression has significant personal and public health consequences, including higher suicide rates and economic costs. Research on recurrence focuses on identifying risk factors, which may differ from those for first-onset depression. Studies have examined demographic variables, clinical features, family history, and psychosocial factors. Gender, socio-economic status, and marital status are not significant risk factors for recurrence. Age at first onset and number of depressive episodes are related to recurrence, though further research is needed to disentangle their roles. Severity of the first episode, as indicated by a severe symptom picture, is also a risk factor for recurrence. Comorbid psychopathology, particularly dysthymia, is associated with increased risk for recurrence. Family history of psychopathology, including depression, is linked to recurrence, with genetic factors playing a significant role. Studies suggest that recurrent depression is influenced by genetic and non-shared environmental factors. Research on genetic loci has identified potential susceptibility loci for recurrent depression, indicating a genetic component. Overall, recurrent depression is linked to a genetic vulnerability that predisposes individuals to recurrent episodes and associated psychosocial risks.Depression is a highly recurrent disorder with significant personal and public health consequences. Researchers have begun to identify risk factors specific to recurrence, which may differ from those for first-onset depression. Methodological issues, including definitions of "recurrence" and "depression," are reviewed, 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). Scar theories are evaluated for their potential to explain how these variables and recurrent depression are linked. The review suggests that recurrent depression reflects an underlying genetic vulnerability that predisposes individuals to recurrent episodes and significant psychosocial risk factors. Major depressive disorder is common, affecting one in six men and one in four women. It is highly recurrent, with 50% of those recovering from a first episode having additional episodes, and 80% of those with two episodes having another recurrence. Recurrent episodes typically begin within five years of the initial episode, with individuals having five to nine episodes in their lifetime. Depression has significant personal and public health consequences, including higher suicide rates and economic costs. Research on recurrence focuses on identifying risk factors, which may differ from those for first-onset depression. Studies have examined demographic variables, clinical features, family history, and psychosocial factors. Gender, socio-economic status, and marital status are not significant risk factors for recurrence. Age at first onset and number of depressive episodes are related to recurrence, though further research is needed to disentangle their roles. Severity of the first episode, as indicated by a severe symptom picture, is also a risk factor for recurrence. Comorbid psychopathology, particularly dysthymia, is associated with increased risk for recurrence. Family history of psychopathology, including depression, is linked to recurrence, with genetic factors playing a significant role. Studies suggest that recurrent depression is influenced by genetic and non-shared environmental factors. Research on genetic loci has identified potential susceptibility loci for recurrent depression, indicating a genetic component. Overall, recurrent depression is linked to a genetic vulnerability that predisposes individuals to recurrent episodes and associated psychosocial risks.