cite: Komori T, Fujiwara R, Tanida M et al. (1995). Effects of citrus fragrance on immune function and depressive states. Neuroimmunomodulation. 2 174-180. 
~ Bob Harris’s database. 

A mixture of orange, lemon and bergamot was used in a study on 20 depressed male inpatients on antidepressants.

The men were divided into 2 groups; one group received antidepressants (AD group) and the other group received antidepressants and was also exposed to fragrance (CF group).

The CF group medication was reduced weekly until their depression remitted (4-11 weeks). The Hamilton Depression Rating Scale and Self-Rating Depression Scale were used to evaluate psychiatric states.

Both scores were improved in both groups. By the end of eleven weeks, nine of the twelve patients in CF group had reduced their antidepressant drug intake to zero, whilst the other three 
had reduced their dosage by 50-75%.

However, all subjects in AD group still needed their usual doses of antidepressants at remission. Urinary cortisol and dopamine levels were significantly high in both groups before treatment, and both were reduced by treatment.

However, the levels were significantly lower in the CF group when compared to the AD group after treatment.

Citrus fragrance caused cell surface markers (CD4/8) values to return to the normal range more effectively than treatment with antidepressants alone. The fragrance also caused high values of Natural Killer cell activity return to almost the normal range.

The mean NK cell activity in the CF group was significantly high when compared to that in the AD group i.e. the citrus fragrance normalized abnormal values of indices of immune dysfunction (Komori et al 1995)