Clinically Depressed Four-Year-Old?

Yes, kids as young as four years of age can be clinically depressed. The intensity and frequency of your daughter's sadness over not having a father would certainly suggest that she merits being seen by a children's therapist. There are therapists who specialize in the treatment of young children and depression. Ask your pediatrician for her recommendations and call the social services departments of the major pediatric centers and children's hospitals in your area. You might also inquire about parents' support groups for yourself.

You are correct that she would not have a memory of her father that is causing her to miss him if he died when she was nine months old. You say that you have been open with her, but have you told her how her father was killed? I wonder how she has processed your explanations of his death. As she became more socialized and saw that most other kids had fathers, her sadness and loneliness grew. While some non-compliance with adults and arguing with peers can be attributed to her age, you speak of her being mean. That concerns me because it's willful and hurtful. I think that she is overwhelmed with confusion and sadness, centered on her not having a daddy. This daily misery has gone on too long not to be addressed therapeutically. I know that you will find your little girl the psychological help that she needs. Her present condition is not going to magically disappear or necessarily get better with age. Her fixation on her father might also be obscuring other chronic emotional difficulties that she is unable to articulate. That's why a seasoned specialist needs to see her, because therapeutic work with a child this young is a complex task.