Psychology in brain tumor patients - how much goes back to the physiology of the tumor and how much to the diagnosis?

The diagnosis of a brain tumor comes for many as a shock followed by depression. This often is also the case, if the brain tumor is benign or a cyst and can be cleared by surgery or left to observation. As described under the topic "neurosurgery", we had a young man in his 30s as patient last year, who developed behavior with features of precocious puberty under a pineal cyst. We are wondering, how much of his behavior might actually be linked to the cyst itself and if you have seen similar cases of changes in behavior?