As for the other types of debt, you might want to tread a bit more carefully. High levels of credit card debt could indicate an impulsive nature and an inability to delay gratification. Gambling debt can be an even worse sign since it could mean an addiction to gambling and other destructive behaviors.
Does He Show a Desire to Change?
Even if your boyfriend has amassed high levels of problem debt from past credit card use, gambling and other vices, he may still be able to turn things around and lead a successful life. Many young people make some serious mistakes when handling money for the first time, and it is easy for things to spiral out of control.
What separates the otherwise financially responsible guy from the lost cause is the desire to change. If your boyfriend now recognizes the error of his ways and genuinely wants to change, you can give him the support he needs to recover. Whether that support is financial, emotional or both is up to you. But if he acknowledges that he has a problem and is willing to work hard to eliminate his debt, the relationship might be worth saving.