There is growing evidence about neuroinflammation in the aetiopathogenesis of bipolar disorder. Early diagnosis and intervention strategies are thought to be excessively important lately.

To check neuroinflammation levels in early stage bipolar disorder and explore the associations with clinical variables.

We aimed to evaluate inflammation and neurodegeneration findings in early stage bipolar disorder.

Serum interleukin 1-receptor antagonist (IL-1Ra), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), high sensitive C reactive protein (hs-CRP), S100B and neuron specific enolase (NSE) levels were assessed by enzyme-linked immunosorbent assays in a total of 30 patients with bipolar disorder in the early stage and compared with 30 matched healthy controls. The clinical symptoms were rated using Montgomery Asberg Depression Scale, Young Mania Rating Scale, Positive and Negative Syndrome Scale and Clinical Global Impression Scale.

Among the patients with bipolar disorder, 14 (% 46.6) were in a manic/hypomanic state and 12 (% 40) were in a euthymic state. Serum IL-6 levels were significantly higher (P = 0.018), TNF-α and S100B levels were significantly lower in the early stage group (P < 0.001 and P = 0.03, respectively). After repeated analysis with only drug-naive patients, the results showed no difference. There was a positive and significant correlation between TNF-α levels and CGI, MADRS scores (all P < 0.05); NSE levels and MADRS scores (P < 0.05).

This study supported the association of early stage bipolar disorder with inflammation and neurodegeneration. IL-6 may be a potential biomarker. Thus, early diagnosis and intervention may be crucial to prevent progressive neuroinflammation and neurodegeneration in early stages of disorder.

The authors have not supplied their declaration of competing interest.