only one or two symptoms to no more than a mild degree), while others experience many
years with few or no symptoms  between discrete episodes. It  is important to distinguish
individuals who present for treatment during an exacerbation of a chronic depressive ill-
ness from those whose symptoms developed recently. Chronicity of depressive symptoms
substantially increases the likelihood of underlying personality, anxiety, and substance
use disorders and decreases the likelihood that  treatment will be followed by full symp-
tom resolution. It is therefore useful to ask individuals presenting with depressive symp-
toms to identify the last period  of at least 2 months during wh ich they were entirely free of
depressive symptoms. 
Recovery typically begins within 3 months of onset for two in five individuals with ma-
jor depression and within 1 year for four in five individuals. Recency of onset is a strong
determinant of the likelihood of near-term recovery, and many individuals who have been
depressed only for several months can be expe cted to recover sponta neously. Features as-
sociated with lower recovery rates, other th an current episode duration, include psychotic
features, prominent anxiety, persona lity disorders, and symptom severity.
The risk of recurrence become s progessively lower over time as the duration of re-
mission increases. The risk is higher in in dividuals whose preceding episode was severe,
in younger individuals, and in individuals who have already experienced multiple epi-
sodes. The persistence of even  mild depressive symptoms du ring remission is a powerful
predictor of recurrence.
Many bipolar illnesses begin with one or mo re depressive episodes, and a substantial
proportion of individuals who initially appear to have ma jor depressive disorder will
prove, in time, to instead have a bipolar disorder. This is more likely in individuals with