Knowledge centre · Illustrated explainer
When depression and substance use occur together
Building a shared picture without assuming which came first.
- Mood
- Shared factors
- Substance use
How to read the diagram
Depression and substance-related difficulties can co-occur. Rather than assuming one is the sole cause of the other, their course over time and shared factors need consideration.
The NIDA report discusses assessment of co-occurring conditions and coordination of support. Two-way arrows do not establish causation in a particular person.
Limits of this account
This is not a self-diagnosis tool or a personal rule about which care should come first.
Sources and their relevance
- NIDA · 2020 — Common Comorbidities with Substance Use Disorders
Discusses co-occurring difficulties and coordinated assessment.
Sources checked: 16 October 2026. Original conceptual diagrams prepared for this site. General information, not individual diagnosis or a care plan.