Alcohol or drugs can exacerbate the symptoms of preexisting psychological conditions. Alternatively, someone with no known history of mental illness can develop a mood disorder from substance abuse. Substance Use Disorder alongside another mental health condition is called a co-occurring disorder.
Mood disorders, Depression or Bipolar Disorder , are the most common co-occurring disorders with substance abuse. Bipolar and Depression symptoms both become worsened from excessive consumption of Alcohol and Drugs.
Some people are genetically inclined to a mood disorder, but never express symptoms strong enough to be clinically relevant. The use of substances, though, seems to trigger strange activity or changes in certain neuropathways that are already unusual in these people. This causes previously manageable and unnoticed abnormalities to become more significant.
Depression and Bipolar Disorder can sustain even in recovery—including those who hadn’t experienced issues before their addictions began. Luckily, addressing co-occurring disorders is integral to most addiction treatment practices.
As with Mood Disorders, there are many people with Schizophrenia and other psychotic disorders whose symptoms worsen from substance abuse. There are also cases of drug-induced psychosis and paranoia, when a person develops symptoms that resemble these psychiatric conditions from alcohol or drug use.
This is usually referred to as drug-induced or substance-induced psychosis. Depending on the substance, as well as the length, quantity and frequency of use, psychosis can persist for varying amounts of time.
Symptoms may only be present while a drug is in the body’s systems in some cases, while they can persist for months into sobriety or indefinitely in other cases.
The most common drugs that cause paranoia and psychosis are Methamphetamine, as well as other Amphetamine analogues, psychedelic drugs, and Crack Cocaine. Meth is particularly notorious for causing persistent psychosis that lasts beyond sobriety. Psychedelic drugs can also do this, especially if the person has a preexisting condition of mental illness or is predisposed genetically.
Actual Brain Damage
Substance abuse can also take a toll on a person’s psyche via brain damage. Many mind-altering substances can cause literal physical damage to the brain. This can limit a person in a number of ways depending on the type and severity of the brain damage.
Some drugs, like Meth and other Amphetamines, are actually neurotoxic. This means that they change the nervous system’s activities in a way that can damage and kill nerve cells. Alcohol, at certain levels and frequency, is also neurotoxic. Other drugs that are neurotoxic are MDMA and Dissociatives, like PCP, DXM and Ketamine.
Another way that substances can cause brain damage is via overdose. If a person stops breathing or breathes too shallowly during an Opiate overdose, the brain won’t receive enough oxygen. This can cause brain cells to die. Overdosing can also cause heart attacks and strokes, which may result in brain damage.