hmmm no. you're supposed to use your PS to write about the path that lead you to want to be a physician. adcoms want to see a story unfold leading to end point of wanting to be a doctor. the story isn't supposed to be written as a checklist of "okay, I needed research, volunteering, etc. to get into med school and did that here..." it's supposed show how you've developed, what you've learned, and how in the end they LED YOU to apply to medical school. wanting to apply medical school isn't supposed to be why you embarked on the journey of all your ECs. AFTER you did your ECs, you realized you want to be a doctor and not the other way around. this came straight from an adcom member I met with in person.
there are specific parts in secondaries that are for indicating gaps in education, problems you had to overcome, explaining extenuating circumstances, etc. I could see it being good bringing up extenuating circumstances in your PS, but only if you show how you grew and learned from them. you definitely do NOT want to blame bad grades on those circumstances. you could say like "while so and so impacted my academics this semester, I learned that blah blah and am a stronger person because of it." but even then, I don't think it's good to show how your grades drop because of something bad that happened in your personal life. they'll assume the samething could happen to you in medical school, which is a red flag for them..."this person cannot balance things well" or something like that...