In 2008 anti-depressants were the third most commonly prescribed drug in America, however many scientists are starting to question their utility in curing the symptoms of depression, a very frequent concurrent disorder of addiction. While anti-depressants are still lauded as a tool in supporting the treatment of depression, new concepts arise, in particular the application of the idea of brain plasticity to the treatment of depression.
In depressed brains, the serotonin signal that communicates with neurons is weakened- therefore it was postulated in the 1960s that selective serotonin reuptake inhibitors (SSRIs) would improve the symptoms and quality of life of depressed patients. Patients showed significant improvements in symptoms, leading to the growth in development and sale of anti-depressants such as Prozac, Paxil and Zoloft.
What comes next?
While there has been evident success with the treatment of depression with SSRIs since the 1960s, current studies begin to show that they may not be as effective as has been believed in the past. Siddartha Mukherjee postulates that depression might be much like a heart attack – there are a number of varying causes for the disease (like smoking, high cholesterol) that manifest in one symptom that causes heart attack: a blood clot. Might depression not be the same? Perhaps much like aspirin can help treat a heart attack no matter what the leading cause of the clot may be, SSRIs can address the eventual symptom of low serotonin no matter what the causes are.
This is incredibly significant, and many current studies point to the reality that this is the case- while SSRIs are useful at treating the resulting symptoms of depression- such as lethargy, lack of motivation, unhappiness- they are not necessarily the wonder drug at addressing the causes of depression scientists once imagined them to be.
Some studies have even shown that the placebo effect was as much as 82% effective for some test subjects as ingesting an SSRI. While this shows SSRIs have negligible effects for those with mild or moderate depression, there remain to be significant improvements quality of life for those with severe depression.
Neural Growth: The discovery that changed how we understand the brain
The idea of how SSRIs function changed significantly in the 1980s when neuroscientist Fred Gage determined that neural growth did occur, but only in the olfactory bulb, where smells are processed, and the hippocampus, where memories are stored. In further studies that placed mice in either enriched or barren environments, he determined that mice living in the enriched cages were demonstrating the same neural growth in the hippocampus as mice in barren cages administered Prozac.
Blocking neural growth led the mice in barren environments to revert to symptoms of depression, whether they were administered Prozac or not. Gage demonstrated that there is more to treating depression than simply boosting serotonin levels in the brain, but that neural growth has a key role to play.
This leads many scientists to postulate that perhaps neural death is a major factor in causing certain types of depression- whether through a stress, genetics, substance abuse or environmental factor- and that the key to addressing this problem is finding ways to stimulate growth.
Depression and Addiction Treatment
Much like new theories on how to treat depression, the techniques for addiction treatment are very similar: there is much focus on neural growth. Since substance abuse severely damages the functioning of certain areas of the brain, much of recovery consists of neural regrowth through cognitive therapy, and other activities such as exercise and meditation. As the damage from substance abuse relates to the compromise of neural transmitters, many of these techniques also apply to the treatment of depression.
Source: Am J Psychiatry 158:377–382, 2001. (NIDA)
This image demonstrates the decrease in dopamine transporters in the brain of a methamphetamine addict.
There is a high rate of connection between substance abuse and depression. The Epidemiologic Catchment Area study (1980-85) conducted by the National Institute on Health (NIH) demonstrated that nearly one-third of all individuals with depression had a concurrent substance abuse problem at some time in their lives. In addition, the National Comorbidity Survey (1990-1) showed that men demonstrating alcohol dependence had a rate of depression three times higher than average, and women four times higher. Depression can emerge as a cause of substance abuse, or a result of the stresses on the mind and everyday life that accompany addiction.
For this reason it is very important for rehab centres such as Sobriety Home and Searidge Foundation to keep up to date with these new developments – concurrent disorders are very common with substance abuse. By treating concurrent disorders like depression with the latest research, it will be possible to treat addiction as well.
For more information and support for depression, have a look at the following links:
NY Times: Post-Prozac Nation by Siddartha Mukherjee
NIDA: Drugs, Brains and Behaviour: The Science of Addiction
Depression Hurts: http://www.depressionhurts.ca/en/
Canadian Network for Mood and Anxiety Treatments (CANMAT). Help & resources. Depression: Am I clinically depressed? http://www.canmat.org/resources/depression/depression_intro.html
Mood Disorders Society of Canada: http://www.mooddisorderscanada.ca/index.php
On Depression and cocaine abuse: http://www.drugabuse.gov/news-events/nida-notes/2008/12/long-term-cocaine-self-administration-depresses-brain-activity
