As someone diagnosed with SZA, I relate to some of these observations and have thoughts on underlying dynamics and causes. First, if caregivers are honest with themselves, everyone’s capacity for empathy and expressions of empathy varies by situation. And a diagnosed person’s situation is changed forever by illness. They may improve or decline with treatment, but will never be quite the same. Caregivers tend to forget that SZ affects thought AND emotion, and since empathy is strongly tied to both these functions, it follows that perception and expression of empathy changes as a direct result of the illness.
Let’s examine the three states you’ve identified: Checked out? In this state he’s likely too distracted by the chaos of this own thoughts, “voices”, delusions, medication side effects, hallucinations, background noise chatter etc, to perceive what he’s “supposed” to be empathetic towards. Angry? Reached the end of his ability to cope, because in addition to this internal chaos, he’s further overstimulated by information or sounds of a child or animal, screaming, barking, meowing, and otherwise expressing emotions he can’t handle, and asked to perform cognitive and emotional labor while he’s struggling to keep himself together as it is. Old self, minus happiness? A good day. Minimal symptoms, but he still has an illness that affects his thoughts and emotions. He may also have a number of underappreciated “negative” symptoms like avolition (lack of motivation), anhedonia (lack of pleasure in formerly enjoyable activities), anasognosia (lack of insight into his disease), and flat affect (lack of expression of emotion) that may foster an underlying depression.
I find it a touch ironic you’re focused on his lack of empathy, yet seem to struggle at accepting and understanding his challenges with a new mental and emotional state. Consider approaching his illness and recovery as you would someone who’s suffered a stroke. Medication may help with the more onerous “positive” symptoms like hallucinations and delusions, but it’s unlikely to completely suppress them or help significantly with negative symptoms. As a stroke sufferer might regain movement or speech, he may be able to adapt and recover from changes to his brain, but that progress may be slow, difficult or seemingly impossible and you may need to reduce your expectations and help with supportive adaptations.
People with SZ and autism can suffer from social-emotional agnosia where they have difficulty reading emotional content from faces, tone of voice or social cues. And as a result their behavior may be perceived as lacking empathy. I’ve had some struggles with this which were compounded by misattributing other’s emotions as directed at me and/or my underlying delusional systems, when the person’s emotions were a result of something or someone else entirely. The resulting embarrassment of reading others emotions wrong, can lead to a “once bitten, twice shy” approach where you’re either hesitant to act on perceptions and attributions without additional confirmation, or you avoid social situations and people altogether, because emotional content can be confusing or confounding.
With support from a therapist and sympathetic workmates, I settled on a mix of the two approaches—venturing out into society as much as I could handle, retreating as necessary to safe-spaces like therapy, acting and voice classes until I built up a circle of friends who I felt comfortable enough with to inquire if I was reading social-emotional situations correctly. Things got much easier then, and I gradually gained confidence to navigate social-emotional situations. I still struggle with processing emotions in-the-moment, as actors say, and I’d turned this into a benefit in the workplace. I’m known to be calm and focused in a crisis, so long as people speak with me clearly, calmly and quietly, avoid reporting the same information or asking for updates repeatedly, and shield me from extraneous information or emotional outbursts that don’t help the situation. When that fails, as with your partner, the pressure exceeds my coping mechanisms and I can get angry and lash out. It doesn’t happen very often, but when it does— it isn’t pretty.
My recovery isn’t typical and the result of over 10 years of individual psychotherapy, psychosocial therapy, and better than average insight and medication compliance. From what you’ve shared about his symptoms and his treatment plan, my impression is your expectations of his level of recovery and functioning are unrealistic as it takes a level of communication about and acceptance of his condition that seems absent. If as before you’re asking these questions to confirm a diagnosis of SZ/SZA, it’s plausible, but an observed lack of empathy intersects with other disorders and neurodivergencies. If a definitive diagnosis is still important to you and you’re unable to obtain that information from your partner or his doctor, we may be able to work backwards from a list of his medications and dosages.