Background: Depression is a common disorder, the etiology is too complex to be explained totally by a single social, developmental, or biological theory. A variety of factors appear to work together to cause or precipitate depressive disorders. Various functions of trace elements deficiency such as zinc link to depression exacerbation.

Objectives: to estimate prevalence of hypozincemia in patients with depression and to compare serum levels of zinc with the severity of depression.                                      

Methods: Cross-sectional comparative study, non-probability convenience sampling was conducted at Out-patient's department of psychiatry in Baghdad Medical City, from March till august 2025. The study tools used measuring serum level of zinc, completed 24-h food recall questionnaires to assess the daily zinc intakes with lists of a variety of foods and their zinc content per serving and PHQ9 score in assessment of severity of depression.

Inclusion criteria: All patients with depression diagnosed by PHQ9 criteria at age groups above 20 years included.

Exclusion criteria: All patients depressive symptoms in the context of other neurological disease psychiatric disorders (e.g., schizophrenia, bipolar disorder, autism) medical illnesses (e.g., coronary artery disease, cancer), or conditions (e.g., pregnancy, postpartum period) and those on medications for any chronic diseases such as mental/congenital or metabolic diseases,  hematology, liver, renal, thyroid disease and those taking vitamin/mineral supplements were excluded.                                                                                

Results: The study showed that serum level of zinc was low among depression 34% with P.value <0.001 and there was statistically significant association.