Hello, I'm Alicia. Thanks for your question. I'm happy to help you today. I have extensive experience in working with people with drug and alcohol addictions, so I believe I can help you develop a better understanding of relapse and the recovery process.
To start, it sounds like you already understand the significance of "hitting rock bottom" - without serious consequences (such as jail, losing one's job, etc) people with drug addictions don't develop a sense of what's at stake - the reward of using is greater, to them, than what might seem like trivial consequences of family issues, fighting with one's spouse, etc. So it sounds like your son in law's brother hit rock bottom and learned from it, but his learning was only temporary and he relapsed - the draw of the "high" is so strong for most addicts that relapse is a very common part of the recovery process.
To answer your question, then, the brain changes in response to continued substance abuse
. Depending on the substance of choice, the brain responds to many drugs with an increase in the production of dopamine, which is a brain chemical - or neurotransmitter -responsible for pleasure and the control of the reward center of the brain. The need becomes physical, then, because the brain requires more and more of the substance to continue to feel the same high. So the addiction becomes stronger - even after treatment, this craving usually remains present. And what's more is that often, the brain changes after extensive substance abuse - so there are changes in the areas of the brain related to judgment and behavioral control that can also persist despite treatment. The need to use again, then, can be caused by the physical need or by external stimuli in your son in law's brother's environment (stress
, difficulties re-engaging in "normal" life - even if he made positive changes, it can be very difficult to uphold them at times.) or a combination of both, which is usually the case. So even the slightest thing (that might seem slight to outsiders) can trigger the desire to use again. It often takes a number of attempts before someone can truly become and stay clean.
Don't give up hope on your son-in-law's brother. It can be heartbreaking to witness this process, but it's something he must go through if he wants to help himself get better. Your support and the support of others around him (family, friends) as well as the proper treatment (even if he's had treatment already, it can take a number of attempts before someone can stay clean) can help him in recovery. Also, you might find these links helpful:
I hope that helps. Best wishes.