The close association of chronic pain with depression is obvious. So, J. Murray  emphasizes that in chronic pain it is necessary first of all to look for depression; S. Tyrer (1985) provides statistics on the presence of mental disorders of a depressive nature in half of patients suffering from chronic pain; according to S.N. Mosolova , chronic pain syndromes are found in 60% of patients with depression. Some authors speak even more definitely, believing that in all cases of chronic pain syndrome there is depression, based on the fact that pain is always accompanied by negative emotional experiences and blocks a person’s ability to receive joy and satisfaction. The greatest controversy is not the fact of the coexistence of chronic pain with depression, but a causal relationship between them. On the one hand, a long-existing pain limits a person’s professional and personal abilities, makes him abandon his usual life stereotypes, violates his life plans, etc. A decline in quality of life can lead to secondary depression. On the other hand, depression can be the root cause of pain or the main mechanism for chronic pain. So, atypical depression can manifest itself under various masks, including under the mask of chronic pain.
In this article, we do not set the task to differentiate the type of depression in all variants of chronic pain syndromes. Our goal is to focus the doctor on the undoubted kinship of these two pathological syndromes, their frequent compatibility, to emphasize the need to search for depression for any chronic pain, to teach us to distinguish clinical symptoms that indicate the presence of depressive symptoms. All of the above is necessary for full assistance to the patient, since depression, regardless of its origin, primary or secondary to chronic pain syndrome, always significantly worsens and modifies the clinical picture, aggravates the pain and suffering of the patient, and reduces the quality of life of the patient. Depression forms the patient’s state of helplessness and complete dependence on the pain syndrome, generates a sense of futility of treatment, leads to a kind of “catastrophic” of his own condition. Figuratively speaking, a peculiar vicious circle is formed between pain and depression, in which one condition exacerbates another.
Often, local or more extensive muscle spasm is also embedded in this vicious circle.
Thus, a full-fledged treatment of a patient with chronic pain is impossible without the relief of coexisting depressive symptoms.
The “kinship” of pain and depression is primarily due to the general links of pathogenesis. Both in chronic pain syndromes and in depression, the insufficiency of serotonergic systems of the brain is determined. The serotonergic theory of depression is currently the leading one, and the dysfunction of the descending serotonergic analgesic systems of the brain in the formation of chronic pain has also been shown to be significant [3-5].
In this context, it is important to determine what is considered acute pain and what is chronic. Acute pain is always a symptom of some kind of organic suffering. On the contrary, chronic pain, as a rule, is not a symptom, but actually a disease, in which not morphological damage to the tissues, but defective perception and other dysfunction of mental processes is crucial.
According to the International Association for the Study of Pain, chronic pain is considered to be pain that lasts beyond the normal healing period and lasts at least 3 months . Currently, chronic pain is considered as an independent disease, based on a pathological process in the somatic sphere and primary or secondary dysfunction of the peripheral and central nervous systems. An integral sign of chronic pain is the formation of emotional and personality disorders, it can only be caused by dysfunction in the mental sphere, i.e. treat idiopathic or psychogenic pain . Psychogenic chronic pain is the most common and most difficult to diagnose and treat. According to the criteria of DSM-IV, the concept of chronic pain is used to refer to pain syndrome lasting more than 6 months.
Chronic pain syndrome can be observed in the clinical picture of any depression. Symptoms of depression in chronic pain can be obvious or erased. Quite often, pain is the “mask” of depression and the actual depressive symptoms appear in an atypical form and are hidden behind the pain that dominates the clinical picture. Among the syndromes of masked depression, some authors separately distinguish the algic-senestopathic syndrome. Patients with typical manifestations of depression quickly find themselves in the field of vision of psychiatrists. On the contrary, patients with atypically leaking, masked depressions are treated for a long time and sometimes to no avail by general practitioners, since it is quite difficult to recognize such a depression.
Chronic pain as a manifestation of masked, somatized depression can be localized in almost any part of the body. Often there is a combination of several locations. Clinical symptoms can mimic various variants of somatic and neurological pathology, therefore, it is necessary to examine the patient in detail. Typically, chronic pain is localized in the head, heart, abdomen, large joints, back. Examples of chronic pain include chronic tension headaches, daily chronic headaches, fibromyalgia, psychogenic cardialgia, and abdomyalgia.
Chronic pain is often diffuse, monotonous, constant, dull, aching, pulling, squeezing. Often, senestopathic sensations join chronic pain. As a rule, chronic pain is poorly described by patients and poorly localized. Typically, the patient indicates a sufficiently large area of pain, which can vary from examination to examination.
Pain is never presented in isolation, but is always combined with complaints of a psychopathological and psycho-vegetative nature. The state of distress, aggravation of psychological conflict, decompensation of emotional-personality disorders always lead to intensification and / or generalization of pain.
Patients with chronic pain and depression have a long history of their disease, they inconclusively, but persistently turn to doctors of various specialties. They conduct numerous studies that do not confirm either somatic or neurological organic disease. These are patients who, despite months of examinations by various specialists, do not have a definite diagnosis. Often they are treated symptomatically, trying to stop the pain syndrome by various analgesic agents. Treatment is ineffective, and patients continue to see doctors.
Diagnosing depression is difficult for a non-psychiatrist. To diagnose depression, you need to know its diagnostic criteria (ICD-10). Diagnostic signs of depression are as follows:
– low or sad mood,
– loss of interests or feelings of pleasure,
– increased fatigue;
– decreased ability to concentrate,
– low self-esteem and self-doubt,
– ideas of guilt and self-abasement,
– a gloomy pessimistic vision of the future,
– suicidal thoughts or actions,
– sleep disturbances,
– appetite disorders
The main are the first three clinical manifestations. The remaining symptoms are additional. To verify a severe depressive episode in the clinical symptoms of a patient, the first three main manifestations of depression, which are combined with at least four additional symptoms, should occupy a leading place. To establish a diagnosis of a depressive episode of moderate severity, the presence of two main and three additional symptoms is necessary. For a mild depressive episode, the presence of two main and two additional symptoms is sufficient. Moreover, in all three variants of depression, its main manifestations should last at least 2 weeks. In general medical practice, mainly patients with mild to moderate depression are observed. If depressive episodes lasting at least 2 weeks are repeated at intervals of several months at least twice, then repeated or recurrent depressive disorders are diagnosed. Repeated depressive episodes can be triggered by a stressful situation.
Most often, the doctor is faced with atypically flowing erased depressions, and therefore he needs to focus on atypical symptoms. It should be emphasized the frequent occurrence of depression anxiety disorders, which often come to the fore, eclipsing the actual depressive symptoms. The combination of depression and anxiety, according to AF Schatzberg , reaches 62%. Particularly specific is the combination of anxiety in combination with muscle tension and depression precisely in chronic pain syndromes.
Particular attention should be paid to the doctor’s attention that patients with atypical depression may complain only of certain persistent somatic symptoms, the main of which are a constant feeling of tiredness and chronic pain. Often the main complaint may be increased irritability.
With atypical depressions, complaints of chronic pain are often combined with complaints of other unpleasant, poorly described and often poorly localized sensations throughout the body, sleep disturbances, appetite, sex drive, increased fatigue, weakness, decreased performance, constipation, dyspepsia; women may have complaints about menstrual irregularities that have no organic cause, premenstrual syndrome. In depressions, poor appetite and a decrease in body weight and, conversely, increased appetite, when patients “jam” their depression, and accordingly an increase in body weight, can be observed . In these cases, eating remains the only way to get positive emotions – all other needs are sharply reduced. For typical depressions, a decrease in appetite and body weight is more characteristic, with atypical depressions the opposite picture is often observed.
The abundance of complaints, their unusual combination, which does not fit into the clinical picture of a single somatic disease, primarily suggests masked depression.
It is specific for depressions that all unpleasant clinical symptoms, including pain, are more present in the morning rather than in the evening.
Sleep disturbances in depression can manifest themselves in very different ways: sleep disturbances, frequent nocturnal awakenings, sleep dissatisfaction, difficulty waking up, an increase in the duration of night sleep, daytime hypersomnia. The most specific sign of depression is considered to be early morning awakenings, in which the patient constantly wakes up for no apparent reason at 4-5 in the morning and can no longer fall asleep.
Very often, general practitioners are faced not only with atypical depression, but also with a chronic version of its course. In this regard, we consider it necessary to familiarize the doctor with the diagnostic criteria for a chronic depressive state, which can coexist with chronic pain. In the classifications ICD-10 and DSM-IV, it stands out under the name “dysthymia.” Previously, this condition was classified as depressive neurosis or neurotic depression. It should be emphasized that dysthymia includes mild chronic depression, in which suicidal thoughts and actions and pronounced social maladaptation do not occur. Patients predominate complaints of general malaise, weakness, fatigue, sleep disturbances and appetite. These complaints, along with the lack of expression of typical depressive complaints, lead the patient not to a psychiatrist, but to a general practitioner. According to statistics, up to 5% of the adult population suffers from dysthymia. This disorder is rarely recognized and therefore rarely treated adequately. What are the necessary criteria for establishing a diagnosis of dysthymia?
Dysthymia is a chronic condition that is characterized by depressed mood for most of the day for more than half of all days in the past two years . Chronically depressed mood should be accompanied by at least two of the following symptoms:
– decreased or increased appetite,
– sleep disturbances or increased drowsiness,
– low working capacity or increased fatigue,
– low self-esteem,
– violation of concentration or indecision,
– a sense of hopelessness.
The listed symptoms are often combined with prolonged pain. Dysthymia can last indefinitely, begin at almost any age, often dysthymia is preceded by severe trauma.
When examining patients with chronic pain to identify depression, special attention should be paid to the anamnesis. Indications of past depressive episodes, mental illness in relatives, alcohol or drug abuse, severe traumatic situation or emotional stress experienced should alert the doctor regarding depression. We must try to identify the connection between the debut and the course of the pain syndrome with the patient’s mental experiences. A children’s history is also important: previous pain experience of the patient, chronic pain in close relatives, attitude to pain in the family, i.e. features of education that can contribute to the formation of the so-called “painful personality”.
Every doctor knows how difficult it is to communicate with a patient with chronic pain. The patient is fixed on his pain, and often the doctor’s questions about his mood, problems, lifestyle, childhood are perceived extremely negatively, causing aggression and irritation. This may be due to the fact that the pain coexisting with depression serves as a kind of protective mechanism, distracting the patient from the intolerable, traumatic psyche, oppressive, painful experiences and memories. Knowing this, the doctor must be patient, sensitive and very careful when questioning the patient.
When examining a patient, it is necessary to pay attention to the patient’s appearance, his posture, manner of holding, speech features and his behavior, which can help in the diagnosis of a depressive state that is not recognized or hidden by the patient. Patients with depression are characterized by carelessness in clothing, preference for gray and dark tones, lack of hairstyles, cosmetics and jewelry for women, poverty of facial expressions and movements sometimes resembling stiffness, a bent posture, inexpressiveness and monotony of speech, monosyllabic answers, etc. In other words, the analysis of “body language” or methods of non-verbal communication helps the doctor in diagnosis.
Thus, there are various combinations of chronic pain with various types of depression.
The physician must pay special attention to the diagnosis of depression in chronic pain syndromes, as depression coexisting with pain significantly complicates and modifies the clinical picture of the disease.
Regardless of whether primary or secondary depression is associated with chronic pain, it must be stopped using psychotherapeutic and psychopharmacological methods of exposure (see the article “Pharmacotherapy for Depression” in this issue of the journal).
With the combination of chronic pain with depression, the first place in therapy is occupied by antidepressants, which have not only antidepressant, but also analgesic effects .
The effectiveness of antidepressants in the treatment of chronic pain syndromes reaches 75% . The effectiveness of antidepressants is higher, the greater the role played by depression in chronic pain.
The mechanisms of analgesic action of antidepressants are as follows:
– analgesic effect in connection with the reduction of depression (this mechanism is especially significant if the pain syndrome was a mask of depression, i.e., with primary depressions. However, with depressions secondary to pain, reduction of depression always leads to a weakening of the pain syndrome);
– analgesic effect in connection with the potentiation of the action of both exogenous and endogenous analgesic substances, mainly opioid peptides;
– analgesic effect in connection with the stimulation of antinociceptive descending mainly serotonergic systems of the brain.
Currently, priority in the treatment of chronic pain are antidepressants with serotonergic activity: tricyclic antidepressants – amitriptyline (tryptisol), doxepin (synequan), clomipramine (anafranil); selective serotonergic antidepressants or serotonin reuptake inhibitors in the presynaptic membrane – SSRIs – fluoxetine, sertraline (zoloft), paroxetine (paxil), fluvoxamine (fevarin).
To obtain a sufficient analgesic and antidepressant effect, antidepressants should be prescribed in a sufficient clinical dose and for a long time. For example, the dose of amitriptyline should not be less than 75 mg, the course of treatment is not less than 6 weeks. Prescribe the drug, gradually increasing the dosage, a quarter of the tablets every 3 days, the main dose (2/3 daily) is given before bedtime, upon reaching the effect, the drug is canceled, gradually reducing the dosage to avoid withdrawal. Fluoxetine is prescribed immediately at a therapeutic dose of 20 mg (one capsule) per day for a period of at least 6 weeks. The withdrawal of the drug can be done simultaneously, as it relates to prolonged antidepressants.
At the same time, the effectiveness of the treatment of chronic pain syndrome increases with the introduction of muscle relaxants of central action, which allows, additionally breaking the vicious circle, affect the pain syndrome and optimize the functional activity of the central nervous system. In addition, a decrease in muscle tension due to the mechanisms of “feedback” allows us to achieve a significant reduction in the anxiety component of the disorder. The drug of choice among central muscle relaxants is tolperisone (midocalm), unlike all other muscle relaxants, which allows you to combine treatment with any psychoactive drugs without the risk of increased side effects, the development of withdrawal syndrome, dependence and / or cumulation.
The results of a study of the analgesic effect of antidepressants and our own experience in the treatment of patients with chronic pain syndromes indicate that the clinical analgesic effect occurs earlier and at lower clinical doses than the antidepressant effect.