Treatment of Comorbid Depression and Substance Abuse in Young People

This study is for young people who are dealing with both depression and drug or alcohol problems at the same time. It tests whether a talking therapy called CBT (Cognitive Behavioural Therapy), specifically designed for both issues together, can help reduce depression and substance use. For those who do not fully respond to CBT, there is also a pilot trial of an antidepressant medicine called sertraline. You may be eligible if: - You are between 16 and 26 years old - You are currently experiencing a major depressive episode (lasting more than one month) - You also have a substance use problem — either a diagnosis of abuse or dependence, or you use any illegal drug at least weekly, or you drink more alcohol than the NHMRC guidelines recommend - English is your preferred language - Your estimated IQ is above 80 You may NOT be eligible if: - You have a current or past history of psychosis, significant head injury, seizures, neurological disease, thyroid problems, or are taking steroids - You are participating in any other study or have been in one in the past 30 days - You have taken an antidepressant in the past 30 days - You are pregnant or breastfeeding, or are a woman of childbearing age not using an accepted form of contraception Talk to your doctor about whether this trial might be right for you.