Definition for Mood disorder
From Biology Forums Dictionary
1) Mood disorder is a group of diagnoses in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV TR) classification system where a disturbance in the person's mood is hypothesized to be the main underlying feature. The classification is known as mood (affective) disorders in ICD 10.
2) Mood disorders are chronic, pervasive emotional states that significantly alter the person's thoughts, behavior, and normal functioning.