One of the outcomes of childhood distress is addiction and the more adversity an individual experiences in his or her childhood the higher their risk of resorting to addictive behaviour to sooth their pain, even temporarily. In other words addiction (alcohol, drugs, shopping, Internet, etc.) is an attempt to seek something from the outside that the individual is not able to generate from within.
What makes childhood experience significant is that the circuitry that modulates the brain's reward chemicals is underdeveloped in traumatized children thus making them more susceptible to addictive behaviours and conduct disorders.
It is also important to note that although addiction is often multigenerational and runs in families it has nothing to do with genetics but is caused by emotional patterns and behaviours that give rise to the same pain and hence, the same desire to escape from it.