How many of you remember the term homeostasis from high school? Although a very simplified model of the human body, most body systems are set up to maintain chemical concentrations and other parameters at constant levels, regardless of what is happening outside the body. The body acts a shock absorber or buffer, resisting quick change that would “shock” the system and likely kill the person. The body adapts – not fully – but enough to maintain life.
How does this apply to drug use? Various drugs of abuse have something in common. They lead to the release of large quantities of dopamine – the “feel-good” chemical. Certain activities, such as sex, also do this and having such a system in place is adaptive for the species as it leads to procreation. However, opiates hijack this system, creating a rush of dopamine, not because one ise engaging in behavior to naturally release dopamine, but because the opiate does it autonomously. Thus, a brain swimming in dopamine becomes the “new normal” and activities that were once pleasurable – like sex – pale in comparison to the “high” experienced when you take the drug.
Over time, the body adapts further and one needs more and more drug to feel good – and eventually simply to avoid getting sick – and addiction is the result.
So what happens when you take the drug away? In the short term, there is withdrawal. That is certainly unpleasant but can be avoided with a careful detoxification process. However, even when detox is complete many patients don’t feel entirely normal. They often can’t enjoy life and slip into depression – which often leads them right back into the cycle of drug abuse.
The reason this occurs can be understood through the concept of homeostasis. Drug use causes brain changes at the receptor level. Just as it took months or years for the receptors to adjust to the high level of exogenous opiates, it takes months or years for the receptors to re-adjust to sobriety. During that time, a patient often feels depressed, cannot find joy in life and is often unmotivated to pursue his/her interests and to take back family and work responsibilities.
Recent studies have demonstrated that the brain will eventually return to a relatively normal state but that may take 3-7 years depending upon a number of factors. That is a long time to feel depressed and frankly, without the help of medication, most patients cannot maintain sobriety for long enough to allow the brain to heal.
What is the solution? Luckily, scientists have developed medications that can mimic the effects of opiates on dopamine receptors. Moreover, these drugs are not addicting and do not cause physical dependence or withdrawal. One such example is Wellbutrin – an antidepressant that works as a dopamine reuptake inhibitor, effectively increasing the effect of dopamine in regions of the brain affected by addiction.
So often I hear from a patient “But doctor – I know it’s all in my head” as a way of dismissing the very real symptoms he/she is experiencing. My response – I agree. “Yes, it is all in your head”, I say but not in the way you are thinking. After a short lesson in neurobiology the patient realizes that he is not “crazy” or “wrong” about the way he/she is feeling. These symptoms are completely legitimate and expected. Moreover, they can be treated with a judicious combination of medications that will provide the bridge to sobriety that many patients need to be successful.