When a patient has mental depression, it can interfere in her life and make it difficult to function. The National Institute of Mental Health (NIMH) states that major depressive disorder and dysthymic disorder are the most common forms of depression, though a patient may be diagnosed with seasonal affective disorder, psychotic depression or postpartum depression instead. Multiple factors can cause depression, such as a traumatic event, substance use and genetics.
Traumatic Event
An event that deeply affects a person can cause mental depression. This event can occur anytime during the person's life. Childhood events, especially those that involve abuse or neglect, can have a stronger impact. Loss can also be a cause of depression, such as the death of a loved one. Stressful situations at school, work or home can also trigger a depressive episode. Examples include pressure to perform at work or school, fights with a significant other and disappointment. Chronic illnesses can also contribute to depression.
Substance Use
Certain chemicals can result in depression, especially if coupled with another cause. A person who abuses alcohol or drugs can experience symptoms of depression as these substances are depressants. A patient already diagnosed with depression may turn to alcohol or drugs to cope with her symptoms but these actually exacerbate them rather than alleviate them. Prescription medications, like sedatives and high blood pressure medications, can also contribute to depression. If a patient is experiencing depression symptoms after starting either of these medications, he should talk to his doctor about changing the medication or dosage.
Genetics
The National Institutes of Health (NIH) notes that depression tends to run in families, and a person with a family history is more likely to develop depression. People without a family history of depression, however, can also develop severe mental depression. The NIMH adds that brain imaging research has shown that a depressed patient has a differently functioning brain, which further supports the idea that genetics plays a role in depression. For example, a depressed patient's brain has abnormal functioning in the regions involved in behavior, mood, thinking, appetite and sleep.
