Yes.

I mean, to elaborate:

1. He avoided interacting with people as much as he could and it was a major part of his character to generally avoid talking to patients unless it was absolutely necessary. If that was the extent of it, it would be fine as some people are introverted, but he savagely insults and humiliates people when he does interact.

2. He had a lack of empathy and was willing to put people through immense amounts of suffering (including willingly trying to forge and coerce patient signatures for extremely risky experimental procedures) if it meant the puzzle was solved at the end (ends justify the means).

3. He was willing to potentially ruin his colleagues’ lives by threatening to discredit them when they attempt to find new employment elsewhere in the medical field when they overly questioned his methods when they believed he went too far and threatened to quit.

4. He drove a car into Cuddy’s house. Not to mention his prank around this time also nearly destroyed the hospital and he would have had to serve another prison sentence (a far longer one) and the main reason he faked his death was to avoid this prison sentence.

5. He snooped in on his colleagues’ personal lives constantly even during extremely inappropriate moments when family members died and therefore refused to respect boundaries.

I’m not necessarily calling him a psychopath because he made mistakes and there are reasons for his behavior, but I think he could plausibly fit the definition.