As I can recall if you take B.Sc in Psychology, you'll be learning a fair bit of Biology especially how the brain system works as it relates to psychological function.

What kind of Biology are you looking for - the entire human body, just the brain alone or plants too?

If you're looking for more Biology, you'd have to look for a double major or double degree.

what's wrong with biopsychology? basically it's how biology affects your behaviour.

neuropsychology would be about your brain and how pathologies would affect your behaviour as well (like, how lesions can cause language difficulties and stuff like that).

i disagree about taking clinical psychology for a balance of psychology and biology, as clinical psychology is more towards assessments, diagnosis and treatment of psychological disorders.

in terms of psychiatry, you wouldnt just be talking about diagnosis, surgery and treatment.

if i'm not wrong, what you study is basically the human anatomy, different systems (such as gastrointestinal, central nervous system etc). train in clinical skills. then you become a doctor. after that you can opt to specialize in psychiatry, which would be a study of mental disorders and assessment, diagnosis and treatment from a biological viewpoint.

i've wanted to do psychiatry before, but realized that i needed to do a medical degree/MBBS before that, so i decided instead to take psychology. i'm currently a third/final-year student in a medical university here.