I have heard that depression causes or is a consequence of a chemical imbalance in the brain. Would this inhibit a potential paranormal experience or make one more likely? Do you know of any studies regarding reported paranormal experiences and the mental health of the of the witness involved. I know this will become tied in with the potential effects of medication being taken, but it's just a thought.

I don't know about depression (which today is used even for states which are not "classic" depression, like chronic fatigue from overwork) but here's an interesting thing.
Dr James Fleming McHarg, Royal Navy military surgeon, much respected psychiatrist in his civilian life and pioonering neurosurgeon, investigated the relation between brain disfunctions and paranormal experiences.
His studies particulary focused on temporal lobe disfunctions, though all the patients who confirmed having had "paranormal" experiences also suffered from very serious ailments, like epilepsy or various brain deformities.
And that's all.

It is not yet known what causes mental disorders. Chemical imbalances noted among patients could be a symptom rather than a cause.

I don't think (based upon just my own experience) that meds make any difference as to being able to sense supernatural activity. I have taken them, off and on (currently off) for three decades, and experienced the unexplainable in both conditions.

P.S. For teh record, I'm not actually 87!