compulsive behaviour is very difficult to stop or control, and is often a result of or a sign of a mental problem [↪ obsessive]
compulsive gambling/overeating/spending etc
Compulsive overspending in these days of credit cards has become more common.
someone who has such a strong desire to eat too much etc that they are unable to control it:
a help group for compulsive overeaters
a book, programme etc that is compulsive is so interesting that you cannot stop reading or watching it
'Gardening World' is compulsive viewing for gardeners.
—compulsiveness noun [uncountable]