The core difference
Psychiatrists complete a medical degree and then specialist psychiatric training. Because they are doctors, they can prescribe medication, order medical investigations and arrange a hospital admission where one is needed. Psychologists are not medical doctors and do not prescribe; their training is in assessment, formulation and psychological treatment.
Both are trained in how thinking, emotion and behaviour work, and both may provide talking therapies.
Getting in the door
You can book a psychologist directly, with no referral at all — a referral only matters for the Medicare rebate. To see a psychiatrist you need a referral from a GP or another doctor, both to be accepted and to claim a Medicare benefit.
Because psychiatrists are fewer and waits are often long, most people start with their GP, who can begin treatment, prepare a Mental Health Care Plan and refer on where a specialist opinion is needed.
When a psychiatrist is the right call
Medication questions, a diagnosis that needs clarifying, severe or long-standing illness, and presentations that have not responded to first-line treatment are the usual reasons a GP refers to psychiatry. Conditions commonly managed in psychiatry include bipolar disorder, schizophrenia, severe depression and complex presentations of anxiety, ADHD, OCD and PTSD.
Usually both, not either
Psychological treatment and medication work through different mechanisms and are frequently combined. Where you are already under a psychiatrist or on medication from your GP, we coordinate with them — with your consent — so treatment pulls in one direction.