Question about Escitaloprám and Amitriptyline taken together

My husband has been on 25 mg amitriptyline for migraine for a few months, seeing a big improvement. Before he started the amitriptyline, he used to take escitaloprám for a couple of years. He stopped it as he started the amitriptyline but became extremely depressed so he started it again at 5 mg together with the 25 mg amitriptyline. The depression improved but he started struggling with overthinking, paying basic attention, started making mistakes in his work and everyday life alongside displaying some very immature behaviour in stressful situations. He now increased the escitaloprám to 10 mg together with the 25 mg amitriptyline. Has anyone been on this combination? Is it a good idea and what to expect?