Concurrent Disorders Support Services (CDSS) serves people experiencing both a psychiatric disorder together with a substance use issue.

The term concurrent disorders (CD for short) may also refer to both psychiatric and gambling issues, but CDSS does not deal with gambling or any addictions other than substance use.

The term concurrent disorders is sometimes confusing because:

• Other terms used to describe both issues have been dual disorders, dual diagnosis, co-morbidity and co-occurring disorders.

• Other countries may use it to describe a person with a psychiatric disorder and developmental disability. In Ontario, a psychiatric disorder and developmental disability is called a dual diagnosis.

(Centre for Addiction and Mental Health)