Distinguishing Depression From Other Disorders
The DSM-IV provides four disclaimers to the clinical diagnosis of depression. It is necessary to describe depression as a mood disorder, which differs from depression associated with other psychiatric or medical conditions. If any of the following four situations apply to a person, depression is not present (following from table of criteria for diagnosis):
- It cannot be established that an organic factor initiated and maintained the disturbance.
- The disturbance is not a normal reaction to the death of a loved one (uncomplicated bereavement).
- At no time during the disturbance have there been delusions or hallucinations for as long as 2 weeks in the absence of prominent mood symptoms (i.e., before the mood symptoms developed or after they have remitted).
- Not superimposed on schizophrenia, schizophreniform disorder, delusional disorder, or psychotic disorder NOS (not otherwise specified)
In addition, it must be determined that the patient has not experienced a manic episode, which indicates a possible diagnosis of bipolar disorder.
APA. Diagnostic and Statistical Manual of Mental Disorders, 4th ed. 1994. Washington, DC: American Psychiatric Association (APA).
A diagnosis of major depressive disorder in the elderly must consider the possibility of dementia, which causes confusion and apathy. The diagnosis in children must consider the possibility of attention deficit disorder (ADD), which causes irritability and loss of concentration. These symptoms are often how children manifest depression.
Many people suffering from depression initially see a physician because of bodily dysfunction, pains, fatigue, loss of concentration, and recurrent worries about their health. Comprehensive neurological and physical examinations rule out medical conditions that cause similar symptoms. For example, thyroid and adrenal gland disorders can cause similar symptoms (e.g., lethargy) and tests can be performed to rule out these medical conditions.
Physicians have established cross-diagnostic checks for evaluating groups of people who are at risk for other psychiatric or medical conditions:
- Teenagers and young adults should be tested for mononucleosis and chronic fatigue syndrome.
- Homosexual men, people with multiple sex partners, and intravenous drug users should be tested for HIV.
- Overweight people should be tested for thyroid and adrenal disorders, sleep apnea, and narcolepsy.
- In the elderly, dementia, Parkinson's disease, epilepsy, and stroke should be considered.
Screening may uncover substance-induced depression. Several drugs can cause side effects that resemble depression symptoms, such as alcohol, barbiturates, cardiac drugs, steroids and hormones, beta-blockers, hypnotics, and stimulants.