Substance abuse and depression are often seen together in teens. For example, when teens get drunk, they often feel excited, stimulated and euphoric. Later in the evening (if they haven't passed out), they may feel depressed and irritable. It is interesting that these negative feelings and the hangover the following morning do not deter many teens from continuing to drink. This is partly because drinking is a very social activity, and teens may not want to lose the benefits associated with being part of a group. Also, they may be looking for the relaxed feeling they get while becoming drunk. However, if they start to drink frequently, they may develop symptoms of depression that persist between the drinking bouts and find that drinking no longer provides a lift. Parents who are not aware of their teen's alcohol use may see that their teen is depressed, but may not realize that this depression is secondary to alcohol abuse.

Teens who are heavy users of alcohol, cigarettes or marijuana are more likely to be depressed than those who are moderate, light or non-users of these drugs. There are a number of theories about why this is so. One theory suggests that depressed teens drink or take other drugs in an attempt to improve their mood, in effect, treating them selves for depression. Another proposes that a tendency to substance abuse is genetically linked with a tendency to depression. Other theories postulate that the same personality, familial and cultural factors that contribute to depression may also be linked to substance abuse. Some researchers believe that substance use causes depressive disorders. It is likely that all of these are true to some extent.

Substance use as self-treatment does not usually work. The teen may experience temporary relief from depressed feelings, but this relief is usually short-lived. Some drugs may help with specific symptoms, like marijuana increasing appetite. But these drugs do not cure depression; in fact, they may make depression worse, may make academic difficulties worse and may even increase the risk of suicide.

Excerpted from Helping Your Teen Overcome Depression: A Guide for Parents - By Dr. Miriam Kaufman, BScN, MD, FRCP.