Appearance and behavior is the first MSE domain because it begins before the first word of the interview. You observe the patient from the moment you greet them — in the waiting room, walking back, sitting down. By the time the formal interview begins, you have substantial data about how they present.
Observe before you interpret. The discipline is to record what you see in specific behavioral language, not what you conclude. "Patient appeared depressed" is interpretation. "Limited eye contact, slumped posture, slow movements, flat facial expression" is observation. The next reader of your note should be able to picture the patient from your description; from your interpretation, they can't tell what you actually saw.
What to attend to: grooming and dress (well-groomed? meticulous? disheveled? bizarre? appropriate to weather?), motor activity (calm? restless? psychomotor retardation? agitation? tremor? tardive dyskinesia? dystonia?), eye contact and engagement (appropriate? avoidant? guarded? piercing?), cooperativeness (calm? hostile? guarded? overly familiar?), apparent age versus stated age (looks older — chronic illness, substance use; looks younger — possibly developmental, sometimes psychiatric).
Motor signs deserve specific attention. Tardive dyskinesia in a patient on long-term antipsychotic — subtle oral-facial movements you might miss if you weren't looking. Acute dystonia — neck deviation, tongue protrusion, eyes rolled up. Akathisia — leg-jiggling, inability to sit still, pacing. Parkinsonism — tremor, masked facies, cogwheeling. These observations change the differential and the medication choices.
Cultural calibration matters. Cultural dress is not disorganization. Religious head coverings are not bizarre appearance. The patient who looks unusual to you may be presenting in entirely culturally appropriate ways. Document specifics; resist the impulse to label what's different as pathological.
Document for the next reader. Specific observations protect both clinical care and chart review. The boilerplate "patient appeared appropriate" tells the next reader nothing; specific behavioral observations tell them everything.