Are allergy sufferers at high risk of mood disorders?

I’ve read that allergies can be related to mood disorders, such as depression and anxiety – true?

He answers Christina ColomboHead of Mood Disorders Center, San Raffaele Hospital, Milan

Allergies are very common (affect up to 20% of the population second Aria, a project supported by the World Health Organization) and it may happen that a patient tells the doctor that he also suffers from depression or anxiety. Allergies can have a seasonal manifestation if we think of pollens, while for other substances or foods they are annual. Depression affects about 8% of adults in Italy and typically has a seasonal recurrence, for which a mechanism of susceptibility of the biological clock to changes in light and circadian rhythms has been evinced. Think of symptoms like insomnia or changes in appetite and body temperature. This susceptibility to the amount of natural light (to the photoperiod) takes place particularly in autumn and spring, accounting for the frequency with which patients report both allergy and mood symptoms.

Depression and sleep

During the acute stage of the allergy there may be disturbances similar to the physical symptoms of depression, for example related to sleep and energy level, with repercussions on performance, just as the awareness of having an illness can worsen mood and anxiety. Plus some allergy medications such as antihistamines and cortisones they can worsen mood and energy, so it is good to report all the drugs you are taking to exclude confounding factors or worsening symptoms. With respect to the possible reasons underlying this association, a clarification is necessary: ​​with depression we identify a group of disorders characterized by low mood, but not all depressions are equal in underlying mechanisms.

Immune system

In recent years there is great interest in the connection between certain types of depression and changes in the immune system
: the data seem to suggest the presence of a mechanism of this type, in addition to the aforementioned biological clock (on which one can act with so-called chronobiological techniques, such as light therapy) and neurotransmitter imbalances, but the results are not yet final. At the moment, therefore, we do not have solid data to causally connect depressive symptoms with allergyn we have reason to be alarmed: both allergy and depression are treated according to modern specific therapeutic protocols, with good (if not excellent) results for both.