Substance-induced mood disorder is characterized by prominent changes in mood, anywhere from depression to mania (overly inflated mood, tending toward grandiose thinking) and related to the cycle of use/disuse common in substance abuse. There has been some evidence of mood disorder symptoms, from over-the-counter medication abuse, such as anxiety and irritable mood after extended use of Benadryl or OTC sleep aids. The criterion for substance-induced mood disorder is sometimes difficult to differentiate from unrelated mood disorders, such as Major Depression or Bipolar Disorder. To meet the criterion for diagnosis, the clinician must find evidence that the mood disorder occurred within one month of intoxication or withdrawal of the medication; the patient must be distressed by the mood changes, reporting significant impairment in daily life; and the clinician can rule out any pre-existing or co-morbid mental illness.
Clinicians became aware of substance-induced mood disorders (SIMD) in the early 1950’s, when a common antihypertensive medication, Reserpine, was linked to acute onset depression. Since then, further studies of SIMD have proven its validity as a diagnosis. Some substance cause mood symptoms in the user at the start of substance consumption; other drugs cause mood symptoms when patient stops consuming the drug. The mood effects include most of the same criteria depression, manic-depression, and anxiety disorders; however, they only last a few days to a few months, after substance abstinence. The most common prescription medications related to SIMD, include clonidine, some corticosteroids, and some antidepressants.
Additionally, many illicit drugs cause symptoms of substance-induced mood disorders. Referred to as the “teeter-totter” effect, which is the explanation those drugs that temporarily elevate mood, such as cocaine and amphetamines, will lead to depressive mood, and drugs that act as depressants, like alcohol and opiates, will lead to agitated and anxious states; some medications cause such extremes as suicidal thoughts or mania. The withdrawal effect on mood from most illicit drugs is commonly diagnosed as a substance induced mood disorder.
The main cause of substance-induced mood disorder is the alternation of the brain chemicals known as neurotransmitters. Many drugs cause the levels of such neurotransmitters to decrease, culminating in depressive behaviors and low energy. The symptoms of SIMDs are similar to that of depression. When the level of neurotransmitters becomes excessive, the patient may experience grandiose thoughts, increased agitation, and excessive energy, similar to that of mania.
How is SIMD Diagnosed?
The key to an accurate diagnosis of substance induced mood disorder is a complete medical history. Typically, if a patient reports an unremarkable mood pattern before substance use or medication use, and the symptoms disappear within a few days or up to a month after abstinence, SIMD is most likely the diagnosis.
Sudden cessation of many drugs, especially among polysubstance users, can lead to dangerous deleterious effects. Sometimes treatment involves introduction of a similar substance or a medication that mimics the actions of the original substance, to manage the withdrawal symptoms, especially mood symptoms. For example, the use of Suboxone and Methadone in heroin cessation is important as an adjunct to traditional treatment because it relieves withdrawal and helps reduce psychological symptoms related to substance use and disuse.
Perhaps knowing that the feelings of depression or mania are only temporary will be a relief for those in early abstinence on the road to recover.