Complex sentence: Depressed patients often view themselves as deficient, helpless, and/or unlovable, and they tend to attribute their unpleasant experiences to their presumed physical, mental, and/or moral deficits.
Split into simpler sentences: Depressed patients often view themselves as deficient, helpless and/or unlovabl. They tend to attribute their unpleasant experiences to their presumed physical, mental, and/or moral deficits.