If someone is described as lacks empathy to an odd affect

[Takemebackto]

What would you take this to mean?

That they don't react in the same way as most other people might . The fact it's mentions as an 'to an odd effect' might be worth asking for clarification on as could be read as detrimental or not.

(Sounds to me like the writer is trying to look cleverer than they are to be honest, it isn't a clear way of describing someone, if that was their task )

In psychiatric terms affect refers to facial expression of emotion. Not sure the sentence makes sense though!

I agree with the pp - it's a garbled sentence and the writer must mean 'effect' rather than 'affect' for it to make any kind of sense. I'd take it to mean the writer wasn't very intelligent but was trying to convey that the subject isn't in tune with those around them, which sometimes creates awkward situations.

X-post with the Howmany - I didn't know 'affect' had a meaning in psychiatry, so ignore what I said about 'effect'.

it’s been written in a psychiatrist report about my son.

I think he meant "and has an odd affect."

Affect in psychiatry means the way someone comes across been speaking...a combination of vocal tone, facial expression and posture.

I suspect he is hinting that your son has autism.

I agree with Cailleach

I suspect he is hinting that your son has autism.
In which case he's not a very good psychiatrist as people with autism tend to be overly empathetic. We just don't always show it in the same way that allistic people do.

Is it "odd" or ODD? It is lacking emotional response or consideration, beyond typical for age.

Affect means emotion