Why does Ponyboy have to be so depressed in The Outsiders?

Technically, Ponyboy does not have to be depressed at all, but he is because he lost two friends and is under a lot of stress.Ponyboy and Johnny get along well and grow close when they are hiding out in the abandoned church together. They share similar interests and bond over The Grapes of Wrath and watching sunsets. Ponyboy feels a real connection with Johnny, and when Johnny dies, Ponyboy is deeply depressed. Dally...

Technically, Ponyboy does not have to be depressed at all, but he is because he lost two friends and is under a lot of stress. Ponyboy and Johnny get along well and grow close when they are hiding out in the abandoned church together. They share similar interests and bond over The Grapes of Wrath and watching sunsets. Ponyboy feels a real connection with Johnny, and when Johnny dies, Ponyboy is deeply depressed. Dally loses his mind when Johnny dies and immediately robs a grocery store. When Dally is gunned down by the police, the entire greaser gang is in shock. Ponyboy seems to suffer from Post-Traumatic Stress Disorder because he becomes callous, unfocused, and violent. Ponyboy tries to imagine that Johnny is still alive and attempts to suppress his painful feelings. He loses interests in school and begins to fail classes. Ponyboy has not only lost his two friends, but suffers from a concussion, and is stressed out about the possibility of being taken out of his home. These tragic, stressful events have caused Ponyboy to become deeply depressed.