The use of alcohol and drugs usually begins with a mood that is anything but depressed, or at least ambivalent. Certainly, someone who uses drugs, even if they are sad or in a bad mood, has the instinct to push their brain in the opposite direction. It is equally certain that, at first, the brain is capable of responding euphorically to the substances being used.
What people do not know, or fail to give sufficient importance to, is that the brain is not designed to sustain the euphoric effects of drugs and alcohol repeatedly or habitually.
The brain functions on chemical fuel. When substances make the engine run at maximum capacity, or otherwise cause it to accelerate rapidly in order to produce euphoria, this fuel is consumed. More importantly, there is no automatic replenishment. This effect can be clearly seen “the day after” using stimulants, alcohol, amphetamines, and similar substances. If use is occasional, the brain can recover with a certain degree of “elasticity.” If use is heavy or repeated at short intervals, a “chemical debt” develops: certain areas of the brain no longer have enough fuel to function properly and therefore settle into an altered, usually reduced, level of functioning.
The problem is that once this “debt” develops, the brain’s response is no longer automatically elastic. When substance use is stopped after a period of repeated use, a few days are not enough to restore normal functioning. The brain’s adaptation to this shortage of “mental fuel” corresponds to an instruction that has become “structured”: at the molecular level, the brain has changed its configuration, and this means that, at least for a while, that configuration will not change. When the brain is repeatedly stimulated to its maximum by substances, it responds by placing itself in a state of rest. If the substances continue to arrive frequently, this resting state becomes, so to speak, “reserved” for a certain period, regardless of what happens. Thus, even if the person subsequently stops using the substance, they will have to wait some time before the brain begins functioning normally on its own again.
If the person continues to expose themselves to substances, even less flexible changes may occur, corresponding to cellular modifications, either increases or decreases in certain components. Compared with other organs, the brain changes slowly, which means that such modifications tend to persist, even when nothing has actually been “broken”—that is, even when there has been no loss of brain tissue. In extreme cases, such as methamphetamine intoxication, an actual loss of brain tissue may also occur.
Depending on the type of substance, the damage may vary. What is consistently affected is mood and the ability to experience pleasure and interest in things, which generally revolve around mood. People who are “survivors” of substance abuse may spend long periods in which, despite being able to abstain from substances or having lost interest in them, they no longer see stimulating or intriguing possibilities in everyday life; in other words, they no longer have a “project of pleasure.”
Paradoxically, the most serious and persistent damage to other functions is more likely to be caused by so-called “soft drugs,” that is, substances that do not tend to produce true dependence.
Depressive syndromes in people who have abused alcohol or drugs therefore have three fundamental characteristics.
The first is that they are centered on apathy, lack of initiative, and a lack of gratification and stimulation, as though the brain were unable to identify pleasure or take an interest in the things that are available. The person’s reward system is like a match that can burn immediately and intensely but only briefly, while being unable to catch fire gradually, build up, and remain lit for a long time. Moreover, producing these “flashes” of pleasure and euphoria often requires a trigger corresponding to risky situations. The person may therefore seek increasingly fleeting or illusory thrills while losing interest in the constructive or lasting aspects of things.
The second aspect is the strongly ego-dystonic attitude toward the mood state. People with a history of substance use tolerate even mild depression poorly because the brain’s automatic reference point is no longer some hypothetical normal baseline, but rather the “empty” euphoria produced by substances. “Feeling bad” is therefore experienced in terms of the gap between the maximum and one notch below adequacy, rather than between one notch below adequacy and adequacy itself.
Often, depression in these individuals is not even “complete,” but is accompanied by an intermittent, apparently normal, or sufficient capacity to function, despite a major difference between how the person appears from the outside and how they say they feel. The person may alternate between periods of apathy and generalized lack of interest and periods of restless craving, as though searching for satisfaction in something that nevertheless does not appear or is not clearly identified. This form of dissatisfaction and inability to “connect with” ordinary pleasures makes relationships conflictual or short-lived.
The third aspect is the “mixed” nature of these depressive states. People with a history of drug use often have a reactive and lively temperament, sometimes sensitive or irritable, sometimes vulnerable. After drug use, anxiety tends to increase, and this anxiety is poorly tolerated and experienced with a sense of urgency and anger. There may be periods of increasing intensity in which the person feels paralyzed or overwhelmed, with rapid and confused thoughts, a sense of urgency, and the feeling that there is no way out but that something must be done to avoid succumbing or “going crazy.”
These states correspond to what is known as a “mixed mood state.” When people experiencing such states have to manage them on their own, they usually try first of all to keep the anxiety under control. The development of unbearable anxiety during or after stopping substance use may lead the person to “switch substances,” perhaps moving from one substance they intend to stop using to another that appears more acceptable and harmless.
Furthermore, when the brain is functioning below its previous level of normality, there is often a shift from “stimulating” substances to “narcotic” or “tranquilizing” substances. This type of progression, which ostensibly pursues the goal of keeping anxiety under control, ultimately worsens the depression.
A widespread and difficult-to-control form of substance-induced depression is that caused by the continued use of tranquilizers. These may have initially been taken for various reasons, ranging from insomnia to panic attacks, and then continued at stable or increasing doses for months or years. Women in particular, even without a history of alcohol or drug use, may resort to tranquilizers to control anxiety, but this can lead to a progressive decline in energy, mood, and the ability to tolerate unpleasant external stimuli.
Treating these conditions is neither simple nor straightforward because, when antidepressant medications are studied to evaluate their effectiveness, people who abuse alcohol or drugs are usually excluded from the study population. However, the number of people whose depression is already present during the first episode together with, or following, a pattern of alcohol or drug use is increasing. As a result, this factor is becoming increasingly important when predicting treatment response or selecting the most appropriate treatment.
Furthermore, treatment focused specifically on depression, without taking additional factors into account, often assumes that alcohol or drug use will disappear if mood improves. This, however, is not necessarily the case. In particular, a treatment approach that regards depression as the origin and central problem of the illness may delay the diagnosis of dependence or alcoholism and may even worsen the course of alcohol and drug use, as can occur with some antidepressants.