Signs of clinical depression — a psychologist's honest checklist

The DSM-5 lists nine criteria for a major depressive episode, and five or more of them for at least two weeks meets threshold. That is the technical answer. In the consulting room, the clinical picture is often clearer than the checklist suggests.

Persistent low mood or loss of interest, most of the day, most days, for two weeks or more. Sleep disturbance — either sleeping too little or too much, with no obvious external cause. Fatigue or loss of energy disproportionate to activity. Difficulty concentrating on things you previously handled easily. Feelings of worthlessness, self-blame, or the emerging sense that you are a burden.

Any three of these lasting more than a fortnight is a signal to take the PHQ-9 on this site. Any one of them at severe intensity, or any thoughts of not wanting to be here, is a signal to talk to a clinician this week.

A bad week after a rough event. Grief in the first months of a loss. Situational sadness that lifts when the situation changes. Introversion. Being tired because you're not sleeping enough. All of these deserve care but they are not clinical depression, and treating them as if they were can be its own harm.

Take the PHQ-9. If your score is mild (5–9), the free AI Psychologist plus a sleep-and-movement protocol will move the needle for most people. Moderate (10–14) is the threshold where I would want a clinician in the loop. Moderate-severe (15–19) and severe (20+) call for a live session and, often, a psychiatry consultation for medication assessment.

The single most useful sentence is: 'I have noticed you seem heavier lately. I am not asking you to explain, just to know I have seen it, and I am here.' That sentence has helped more of my patients into treatment than any professional referral I have written.