Addiction is any compulsive behavior or obsessive thinking that generates serious damage and losses and that, despite efforts and attempts, the person cannot stop. It could be addiction to alcohol, drugs, medication, sex, romance, flirting, food, gambling, or negative emotions. For all these cases there is full recovery.

Anxiety is excessive preoccupation with the future, to the point that we lose the pleasure of the present moment. She can be  with or without legitimate reasons, but in all cases they cause serious damage to the personal or professional life of those who suffer. When a person feels that they are isolating or running away through behavior that dulls their feelings, it may be that the person needs professional help.

Feeling sad is legitimate and important. Depression is different from sadness. Depression is a more persistent state that involves a feeling of low vitality, negative thoughts and a lack of existential feeling for long periods with or without reasons.

Life is the school of loss. The problem happens when we can't overcome them, which can be a trauma. In these cases we acquire maladaptive behaviors that hinder our relationships  and our ability to trust life and others. Over time, an avoidant behavior (one that runs away from pain) can turn into a phobia. Professional help in these cases is indicated.