Is there always an underlying cause for developing mental illnesses?

Different therapists and different psychologists say different things. It's either nature or nuture. You were either born that way or you were raised that way. I believe people are born with chemical imbalances in their brains and that's what causes it. It could be a hormonal imbalance that caused it to happen in the past 2 years. Did something traumatic happen to you? Something happens to trigger the brain to become imbalanced.

Look, I have a friend with schizophrenia. First of all, she have inherit the gene responsible for it, otherwise she would never ever develop it.

But during the course of her life she has had many events that has caused stress and anxiety like being kidnapped, not being welcome in a work environment and those things that have triggered the decease.

Now, according to her doctors, she has been informed that for instance, mood swings can be caused by use of drugs (cocaine, heroin etc...). These drugs can trigger some (not all of illnesses) mental conditions.

You said minus ocd. Is ocd in your family? You know most of my maternal relatives are bipolar, but then there I am and I am schizophrenic. Come to find out there was schizophrenia in my maternal grand fathers family. One of my doctors told me all of these illnesses are a spectrum, knid of like a color wheel where everything touches the edge of another. Heredity (genes) plays a large part of this. OCD in one family member may manifest as another illness in a different family member. Look at your family history.

Seems like the therapist is trying to open up conversation with you, so they can learn about who you are. The better they know you, the better they can help you. Try letting them know stuff about you in the past 2-3 years. Also, about things now in the present. In your conversations you might learn if there was something that triggered you that you hadn't thought of before.

nobody can really answer your question--nobody knows if there is ALWAYS an underlying cause for mental illnesses

i certainly know that triggers are normally traumatic and the mind tends to block out/prevent you from remembering traumatic experiences

it hurts to remember

i dont know