Be forewarned, I lean to toward environmental influences for explaining behavior, not toward genetic influences. Put another way, I look for external causation in human behavior. I do not look to genetic causation in human behavior.
I find most external stress causing environments cause human sadness and addiction, not a genetic pre-disposition to alcoholism or drug addiction. I see alcohol as a drug most often used to reduce stress, however temporairly. My work with heroin addicts cinched this theory for me. Too often I've heard statements like these: "Heroin makes me feel like nothing really matters" and "Anxiety disappears."
I see parental ignorance as a major cause for stress causing addictions among abused children. By "abuse" I include verbal abuse, emotional abuse, psychological abuse, and negligence.
Briefly put, addictive behavior arises as a means of self-medicating, long-enduring, mal-adaptive stress from childhood and later. Stress inflicting influences in early years set a deep wide foundation for emotional growth to follow.
For genes, we have no more proof of addiction genes any more than we have proof of race genes. They simply do not exist as causes in the external world. They do exist as potential enablers, biologically, that is.
In stricter terms, we are born into the world as biological bundles of potentiality. Our potentials play out within environmental influences, usually. Genes come into play, not as causes, but as windows of opportunity or walls of closure. For example, few of us become piano players without fingers at birth.
Human behavior is learned behavior. While learning this behavior our genes kick in or kick out. Parental influences do cause behavior in their children. Parental influences do cause emotional stability or emotional instability in their children. Parental genes do not cause instability in their children, generally.
Nothing shows in the body like a sad life created by stress. And a drug addiction begins with a sad life created by stress. Abused children in their turn sometime become sad human beings seeking control of childhood induced stress.
Stresses instinguished during childhood remain during an adult life. Self-medicating drug abuse, including alcoholism, show a sad life in progress What about drug and alcohol abuse recovery?
We know from many psychological and sociological studies that adopted children have the highest rate of chemical abuse. Acceptance, respect, and a feeling of understanding. Given these relationship attributes with adults goes farther than other approaches to recovery. Preaching, condemning, belittling rarely help,
Since philosophy slowly moved aside, or rather emerged as our social sciences, we have learned much. Prior to social scientific investigations social problems remained the relm of individual philosophers. Some of these philosophers were great thinkers and tinkered with power ideas about humanity and the human condition.
Of course suicide received its fair share of attention. Homicide too received a fair amount of attention. In no case did philosophers approach suicide, for example, in a quantifiable manner until Emile Durkheim began researching suicide.
With Durkheim positivist philosophy grew as a social science based on quantifiable methods. Statistical methods became the stuff of social theories. Suicide became the subject studied for its quantifiable information.