What class of psychological disorders involves disturbances in mood states?

Mood Disorders are characterized by significant disturbances in a person's mood or emotional state. This class of disorders includes conditions such as depression and bipolar disorder, where individuals experience extreme mood swings ranging from elation to deep sadness. The defining feature of mood disorders is their direct impact on the individual's emotional well-being and functioning, which can affect various aspects of life, including relationships, work, and general health.

The other classes mentioned, such as Dissociative Disorders, which involve disruptions in consciousness or identity, Personality Disorders, which are characterized by enduring patterns of behavior and inner experiences that deviate from cultural expectations, and Schizophrenia, which centers around disturbances in thought processes and perceptions, do not primarily focus on mood alterations. Thus, the focus on emotional states distinctly positions Mood Disorders as involving the most recognizable disturbances in mood.