Persistent depressive disorder (PDD), also known as dysthymia, is a relatively new addition to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). It contains aspects of 2 diseases from the fourth edition of the DSM: chronic major depressive disorder and dysthymic disorder. Evidence suggests the 2 conditions are different enough to warrant changes in treatment.

The hallmark symptoms of PDD are depressed mood occurring for at least 2 years along with 2 or more of the following symptoms: change in appetite, insomnia / hypersomnia, fatigue, low self-esteem, feelings of hopelessness, or impaired concentration. The length of time needed for diagnosis is different for children, only requiring at least a year of symptoms. Onset of symptoms often occurs in the teenage years.

Risk factors include parental loss or separation, family history of depression, and the presence of coexisting anxiety disorders or conduct disorders.

Proper screening in the primary care setting should be conducted.