[Davis Webb]

Originally Posted by DenverSteve

All and both - but it doesn't matter. Depression is a condition that should not be ignored and should be discussed, diagnosed and treated by a qualified medical doctor. To your question, the below cites numerous etiologies.

Depression is a heterogeneous disorder in which a number of underlying presentations may share a common phenomenology but have different aetiologies. Despite considerable work on the aetiology of depression including neurobiological, genetic and psychological studies, no reliable classificatory system has emerged that links either to the underlying aetiology or has proven strongly predictive of response to treatment. A number of classification systems/subgroupings have been used, including reactive and endogenous depression, melancholia, atypical depression, depression with a seasonal pattern/seasonal affective disorder and dysthymia. These have been based on varying combinations of the nature, number, severity, pattern and duration of symptoms, and in some cases the assumed aetiology.

Not sure that helps us out here. All and both never really narrows things down. Are you saying there is no increase in incidence, or there is?