CONSTANCE: People fall in love, as they put it, because they respond to a certain hair coloring or vocal tones or mannerisms that remind them of their parents.
BALLANTYNE: Or... or... sometimes for no reason at all.
The film mostly shows psychoanalysis as working perfectly—it solves the murder, after all. But psychoanalysis can't explain love; in fact, Constance is presented as being kind of silly for thinking that it can. Psychoanalysis is all well and good for a Hollywood plot, but Hollywood's first love is still love. Don't mess with love, psychoanalysis. Hollywood will kick you if you try.
CONSTANCE: But it doesn't happen like that, in a day.
BALLANTYNE: It happens in a moment sometimes. I felt it this afternoon. It was like lightning striking.
The love presented in Spellbound is that big old cliché, love at first sight. The film doesn't take time to develop the characters and show them falling for each other; it just hits them with a lightning strike. There's a plot to get rolling here, with police chases and everything. Get moving.
BRULOV: Women make the best psychoanalysts until they fall in love. After that they make the best patients.
Brulov is supposed to be cute and crusty, but you could also see him as a misogynist jerk. Love is presented as being especially a problem for women professionals. Guys, supposedly, can love and be smart and scientific, but it's too much for poor women. Of course, Constance eventually ends up being right about everything, but Brulov never apologizes or says, "Sorry, you were correct. I was a sexist jerk." Really, Constance should have kicked him in the shins, the creep.
BRULOV: We both know that the mind of a woman in love is operating on the lowest level of the intellect
CONSTANCE: …The mind isn't everything. The heart can see deeper sometimes.
Again with the sexist comments about women in love, Brulov. And Constance doesn't really argue with him; she seems to agree that her mind is besotted and waterlogged with love. We've mentioned that the film is nervous about Constance's professional accomplishments, right?
BRULOV: Did you recognize this kissing bug?
BALLANTYNE: I'm afraid she looked a little like Constance.
BRULOV: This is plain, ordinary, wishful dreaming. Go on.
Notice the difference here between Brulov's comments on Ballantyne's love and the way he talks about Constance's love. Constance in love is supposed to ruin her as a psychologist; it's presented as a derangement. Ballantyne, on the other hand, is having these sexual fantasies, and Brulov says, oh, right, they're totally normal, nothing to worry about. Guys can be in love, and oh, that's fine. Thanks, Brulov. You jerk.