Although the diagnosis of bipolar disorder is currently based on clinical criteria, preliminary studies showed that palmitic and arachidonic acid levels are able to discriminate adult patients with major depressive disorder (MDD) from those with bipolar disorder (BD).

To replicate and to expand previous findings by investigating the relation between mood disorders and platelet and plasmatic fatty levels.

To compare the lipidic profile of individuals with different mood disorder (MDD vs. BD) and to investigate the relation with specific clinical features (duration of illness, attempted suicide, psychotic symptoms).

Potential participants were recruited from the outpatient and inpatient psychiatric units of the university hospital of Palermo (Italy). Diagnosis of DSM IV mood disorders was made using the MINI. Symptom severity was assessed using the HAM-D rating scale and the YMRS. Fatty acid profile was analyzed using mass spectrometry.

Preliminary analyses were performed on 8 patients with MDD and 6 with BD. Groups were similar in terms of demographic variables. Patients with MDD showed highest levels of platelet palmitic acid, stearic acid, and arachidonic acid. Furthermore, plasmatic docosahexaenoic acid was negatively related with manic symptoms severity (Rho = –0.697; P = 0.025) and platelet alpha linolenic acid was positively related with illness duration (Rho = 0.845; P = 0.040).

These preliminary findings suggest that platelet fatty acids may be possible biological markers to improve the diagnosis of BD.

The authors have not supplied their declaration of competing interest.