Alexis experiences persistent feelings of sadness, loss of interest in activities, changes in appetite, and difficulty sleeping for more than two weeks. According to the DSM-5, which psychological disorder is Alexis most likely experiencing?

Understand that Major Depressive Disorder (MDD) is characterized by a depressed mood or loss of interest/pleasure in most activities, along with other symptoms such as appetite changes and sleep disturbances, lasting at least two weeks.

Compare the symptoms with other disorders listed: Generalized Anxiety Disorder involves excessive worry, Obsessive-Compulsive Disorder involves intrusive thoughts and repetitive behaviors, and Bipolar I Disorder includes episodes of mania, which are not described here.