Structured psychiatric diagnoses and self-rated symptoms in primary care patients on sick leave for common mental disorders: a clinical study

Background: To improve the quality of health care provided to primary care patients with mental disorders, it is crucial to understand more about the mental symptoms that underlie diagnoses on sick leave certificates. This study therefore aimed to: 1) investigate whether diagnoses on sick leave certificates corresponded to the results of a structured psychiatric interview and to self-rated symptom severity and 2) investigate the association between length of sick leave and the diagnoses on sick leave certificates, the diagnoses made in structured psychiatric interviews, and self-rated symptom severity. Methods: The study used data from 480 patients in SAFARI, a study on sick leave in patients with common mental disorders. At baseline, background variables were gathered and structured psychiatric interviews (M.I.N.I.) were performed. Severity of depression and adjustment disorder was assessed via self-rating scales. Data on sick leave were gathered at baseline and at 12 months from the Swedish Social Insurance Agency and patients’ medical records. Results: The diagnostic criteria for depression were fulfilled by a total of 76% of patients with a sick-leave diagnosis of adjustment disorder, 67% with a sick-leave diagnosis of anxiety, and 65% with a sick-leave diagnosis of depression (p=0.04). There was no significant difference in mean net sick leave days between those with a sick-leave certificate diagnosis of adjustment disorder (mean days 119.9), anxiety disorder (107.2), or depression (137.1). However, those with depression diagnosed via structured interview had a shorter mean net sick leave (112.3) than those who did not fulfil the depression criteria (155.9). Symptom severity was strongly associated with net sick leave days; those who rated their depression or adjustment disorder symptoms as more severe had longer net sick leave. Conclusions: Many patients with sick-leave certificate diagnoses of adjustment and anxiety disorders have ongoing depression. Longer sick leave duration was observed in those with adjustment disorder and more severe self-reported symptoms, both of which are appropriate according to Swedish guidelines.