Depression's certainty about permanence is itself a symptom, not a fact

Haig repeatedly returns to the observation that depression does not just cause pain, it also produces a powerful cognitive distortion convincing the sufferer that the pain will never end and that no argument to the contrary can be trusted. He describes his own worst period as one where he was intellectually certain that things could not improve, even though he now knows, from the vantage of a recovered life years later, that this certainty was false. His argument is that this feeling of permanence should itself be treated as a diagnostic symptom of the illness rather than as reliable information about the future, similar to how a fever distorts perception without being a trustworthy guide to reality. He suggests that recognizing this pattern, that depression lies specifically about its own duration, can create a small wedge of doubt useful for surviving the worst moments. Takeaway: when depression insists it will never end, that insistence is a symptom, not a forecast.