Patterns of sensitisation in the course of affective illness: A life-charting study of treatment-refractory depressed patients

Background: A ‘sensitisation’ process over time has been suggested by Post and collaborators — the affective illness course shows a tendency towards more frequent, deeper, and less stress-related episodes over time. The main aim of the present study was to test the sensitisation hypothesis using a Swedish Life Charting program. Methods: Thirty patients with treatment-refractory affective disorder, of whom four had bipolar I disorder, were first interviewed using a semistructural interview manual covering episodes, treatment and stress. All previous psychiatric records were then recruited. Information from the records and from the interview was coalesced into individual, retrospective life charts. Results: Twenty patients showed a sensitisation course and 10 patients showed a non-sensitisation course. In both groups, almost 90% of illness episodes had undergone treatment. Time spent in illness since onset of the affective disorder was about 33% for the sensitisation group and more than 50% for the non-sensitisation group. Limitations: The retrospective nature of the study is a limitation. The results apply to patients with severe treatment-refractory affective disorder and may not be generalisable to general patients with less-severe mood disorders. Conclusions: Our results partially validate the Post hypothesis of affective sensitisation in demonstrating this phenomenon in more than half of our affectively recurring patients. However, a substantial minority were clearly non-sensitisers showing a stable but more malignant illness course. Future studies need to elucidate whether these two groups benefit from different kinds of treatment.