For a person who is already going through changes in their mood due to puberty, it may be difficult for you to identify changes related to drug abuse. Much of the effectiveness of illicit substances is centered around changes to the brain. Most drugs, like marijuana, cocaine, and heroin directly target various neurotransmitters, like GABA and dopamine receptors. However, with regular substance abuse, the effects caused by drugs can bleed over into everyday life, causing significant mood changes to a previously stable, happy teen.
When using drugs, many teens are subject to erratic moods that go beyond the typical moodswings associated with adolescence. Teens may be anxious, absent-minded, paranoid, aggressive in inappropriate situations, or may seem apathetic and disinterested in fun activities.
Changes to how neurotransmitters respond in the brain can make it much harder for teens to be happy when not on drugs after they have been abusing them for sometime. This leads to switching from moodiness to depressive symptoms at an erratic rate. Alternately, when on drugs, teens may be exhilarated and excited, showing extreme enthusiasm, pleasure, or relaxation. When they are not on drugs or have more, they will want or feel like they need their new drug of choice to balance them out again. This can breed a drug seeking behavior that can spiral out of control real quick.
Some teens, especially those who have developed a dependency and a growing tolerance to illicit substances, may also show signs of withdrawal when access is restricted. While different for every substance, common effects to mood include agitation, irritability, paranoia, and anxiety. Teens may also be quick to anger or extremely irritable until more drugs are secured. For more information about how drug abuse changes the brain, check out the addicted brain video.