| Δ0 | the Getting Things Done methodology itself | GTD, the GTD weekly review, GTD inbox processing, GTD next-action lists |
| Δ1 | other structured personal productivity systems | Bullet Journaling, Zettelkasten, Personal Kanban, the Autofocus system, PARA method |
| Δ2 | other mainstream self-help and life-coaching approaches | The 7 Habits of Highly Effective People, Tony Robbins coaching, vision boarding, morning routines, journaling practices |
| Δ3 | relaxation and stress-reduction practices not classed as therapy | progressive muscle relaxation, guided meditation apps, breathing exercises, aromatherapy, adult coloring books |
| Δ4 | evidence-based clinical interventions for anxiety | cognitive behavioral therapy, exposure therapy, SSRIs, beta-blockers for situational anxiety, mindfulness-based stress reduction |
| Δ5 | general lifestyle habits unrelated to productivity or mental health treatment | eating a balanced diet, taking regular walks, getting enough sleep, drinking water, spending time outdoors |