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People who are alcohol addict, their mind stops working when they drink more alcohol but still they don't make decision which ruin their lives whereas the gambling addicts are so cruel to themselves, their mins is also working yet they keep on playing, take loan, sell their belongings only to play more gamble or recover their losses.
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Alcohol, substance, and gambling addictions, they all sometimes contribute to aggressive behavior of the person, behaviors, and decisions that could ruin their lives or others'. It is not limited to gambling addiction alone.
From the article shared by the OP, the 65-year-old grandfather could be in deep gambling addiction; he would never do what he has done if not.