Is depression caused by a chemical imbalance in the brain?
You’ve seen it in television ads, read it in newspaper articles, maybe even heard it from your doctor: depression is caused by a chemical imbalance in the brain that medication can correct. According to the chemical imbalance theory, low levels of the brain chemical serotonin lead to depression and depression medication works by bringing serotonin levels back to normal. However, the truth is that researchers know very little about how antidepressants work. There is no test that can measure the amount of serotonin in the living brain – no way to even know what a low or normal level of serotonin is, let alone show that depression medication fixes these levels. While antidepressant drugs such as Prozac increase serotonin levels in the brain, this doesn’t mean that depression is caused by a serotonin shortage. After all, aspirin may cure a headache, but it doesn’t mean that headaches are caused by an aspirin deficiency. Furthermore, many studies contradict the chemical imbalance theory of
