CASC: Behavioural activation — evening withdrawal in depression

Candidate instructions

You are the psychiatry registrar. Sam, 38, teacher, major depression for 4 months. PHQ-9 was 18 last week. Evenings: bed, scrolling, cancelled social plans, "I'll start when I feel motivated." No psychosis. Passive death wishes when most withdrawn; no plan or intent today. Prefers a practical therapy start rather than a long CBT wait. Tasks in 10 minutes:[14][15]

1. Engage and set a collaborative agenda about low activity and mood.
2. Explain BA outside-in model briefly without lecturing.
3. Map one evening TRAP and co-create a TRAC alternative.
4. Negotiate one graded, scheduled homework for the next 48 hours.
5. Screen risk (suicide) and safety-net.
6. Agree follow-up and what success looks like.

Actor brief (Sam)

• Soft-spoken, tired, not hostile.
• Sustain talk: "Motivation has to come first"; "I've failed exercise plans before."
• Offers change talk if graded and collaborative: cares about teaching well, misses a friend, wants energy for weekends.
• Shuts down if told to "just go to the gym daily."
• Will accept a tiny evening plan (10-minute walk or shower at 7 pm) if co-created.
• Admits passive death wishes when in bed all evening; denies plan/intent; agrees to crisis contacts.

Marking grid (domains)

Model process (time map)

0–2 min — Engage/focus. "We can talk about evenings, work energy, sleep, or what matters most — where shall we start?" Permission to discuss activity and mood links.[14]

2–5 min — Model and TRAP. "Depression often shrinks life; waiting for motivation can keep the loop going. Small scheduled steps can come first." Map Trigger–low mood–bed. Invite TRAC alternative Sam believes is doable.[14][15]

5–8 min — Plan and risk. Co-create one task with day/time and backup if energy is lower. Ask about suicide ideation, intent, plans, protective factors; crisis numbers; who to call. Link BA evidence briefly without overselling (effective option; works for many; not magic).[1][5][12]

8–10 min — Close. Summarise plan, diary if possible, review date, what to do if worse tonight.[14][15]

Sample high-scoring utterances

• "Part of you wants evenings to change, and part of you is exhausted — both make sense."
• "If motivation is a 2/10, what is a 10-minute step you could still do at 7 pm?"
• "When the urge to go straight to bed hits, what is Plan B that still counts as showing up?"
• "When you are most withdrawn, do thoughts of death show up? Any plan to act on them?"

Common station fails

Blaming laziness; prescribing a full week of intense exercise; ignoring risk; no specific schedule; promising cure; starting complex thought records while patient is too slowed to engage; skipping follow-up.[14][15]