Longitudinal

Longitudinal is a term that is used to describe (or specify) the course of of some mood disorders. It describes whether or not someone fully recovers between different mood episodes.
==Longitudinal course specifiers in the DSM==
The DSM uses longitudinal course specifiers to describe the following mood disorders:
*Recurrent major depressive disorder
*Bipolar I disorder
*Bipolar II disorder
A person can experience either of the following:
*With full interepisode recovery - if full remission occurs between the last two mood episodes
*Without full interepisode recovery - if full remission does not occur between the last two mood episodes
The second specifier can be similar to double depression, when both major depressive disorder and dysthymic disorder are present. It depends on which mood disorder occurred first. If dysthymic disorder was present and then 
major depressive disorder developed, it is referred to as double depression. If major depressive disorder was present which developed into dysthymic disorder, it is usually considered major depressive disorder in remission.