One facet of the human condition is the extent of control people feel they have over their lives. Successful people, for example, tend to view their achievements as a product of their own sweat, labor, risk taking and decision-making. By contrast there is a take on life that is essentially powerless. This is the person who feels no matter what they do, or where they turn, negative things will happen to them. It can easily lead to a fatalistic mind-set where life is hard, people aren't to be trusted and happiness is for others to enjoy.
One major implication of a victim mentality is a view that problems cannot be solved. Here is a person who is generally passive and waits for the next knock-back or put down. They feel frustrated, angry, and depressed at the hand they feel they've been dealt. Instead of viewing themselves as having a role or responsibility for their situation they are inclined to point the finger at external circumstances or other people for their perceived misfortune.
I suspect most people will recognize at least some of these characteristics in themselves. If times are tough it can sometimes be hard not to wonder what we've done to deserve it? Sensitivities tend to increase and we might become more tetchy, irritable and less forgiving. This however tends to be a low point in life and with a bit of time or effort the situation is resolved and we get back in the saddle. Imagine, if you can, the debilitating effect such a mindset can have if it rarely if ever changes. Every aspect of life from relationships, to work, to leisure time will be affected. Moreover, living with someone who views him or herself as a victim can be emotionally draining.
Some victims are more verbal than others. They may moan and complain and see the negative in every situation. This isn't always the case. Some simmer quietly beneath an outward mask of fortitude but inside they feel anxious, resentful and discouraged.
Although the expression of victim mentalities may differ the common thread is that victim mentality is learned and this at least gives some hope that it might change. Victim mentality can also vary somewhat in extent and depth. Because it is so closely associated with negative thinking it is just possible the person could become depressed. If psychological therapy is sought for depression it is inevitable that the therapist will pick up the negative core beliefs that seem to be underpinning the depression.
Breaking out of victim mentality isn't an easy thing to do and it does seem to require insight and motivation. For those who live or work with someone who has a victim mentality it's perhaps useful not to feed or challenge their perception of injustice so much as encourage them to consider their own solutions.