WO1990006760A1

WO1990006760A1 - Pharmaceutical compositions containing brucella or derivatives thereof

Info

Publication number: WO1990006760A1
Application number: PCT/EP1989/001500
Authority: WO
Inventors: Alberto Indrio
Original assignee: Alberto Indrio
Priority date: 1988-12-13
Filing date: 1989-12-06
Publication date: 1990-06-28
Also published as: IT1227892B; IT8822934A0; AU4666389A

Abstract

Pharmaceutical compositions having activity against depression, anxiety, multiple sclerosis, Alzheimer's disease and Parkinson's disease contain as the active ingredient anti-melitensis vaccine comprising various forms of Brucella microorganisms such as Brucella melitensis, Brucella abortus bovis and Brucella intermedia.

Description

PHARMACEUTICAL COMPOSITIONS CONTAINING BRUCELLA OR DERIVATIVES THEREOF.

FIELD OF THE INVENTION

The present invention relates to pharmaceutical compositions active against depression, anxiety, multiple sclerosis, Alzheimer's disease and Parkinson's disease. The invention also relates to the use of anti-melitensis vaccines for the preparation of pharmaceutical compositions useful in the treatment of said diseases.

BACKGROUND OF THE INVENTION

The terms anxiety and/or depression are used to define a pathological condition which is increasing in frequency and which is characterized by psycho-motor symptoms, neuro-vegetative symptoms and behavioral symptoms. The therapeutic treatments presently used consist in administering pharmaceutical drugs such as benzodiazepines , tricyclic anti-depressants, mono-amino- oxydase inhibitors, etc. which have produced a temporary effect with some patients, but are rarely a permanent cure. Also, the use of such preparations presents many undesirable problems such as side effects, acute intoxication phenomena, physical and psychic dependence and possible interactions with other pharmaceuticals. Multiple sclerosis is an inflammatory disease of the central nervous system, probably induced by unidentified viral agents, characterized by random patches or plaques of inflammation, with loss of myelin (a protective material surrounding nerve fibers in the white matter of the brain and spinal cord) . The most frequent symptoms of this disease are motor disturbances (paresis and paralysis) , cerebral disturbances (trepidation, scandium, ataxia) and ocular disturbances. Functional disturbances and psychic disorders such as anxiety and depression are also frequent. To date the recommended remedy for acute multiple sclerosis has been the administration of steroids at high dosages and ACTH (adrenocorticotropic hormone) at high and then decreased dosages. For the chronical situation no valid cure for the .-disease has yet been found. Alzheimer's disease (senile dementia) appears between the age of 45 and 65 with a slight prevalence in the female sex. The histologic changes (senile plaques, neurofibrillar changes, etc.) abundantly damage the cortex cerebri, although this process is sometimes limited to the frontal or temporal lobes. The intellectual functions deteriorate; at the beginning the clinical pattern can present itself like a psychogenic disorder with anxiety and depression, then being followed by disorientation, ^~e memory disorders and reduced comprehension and judgment capacity. So far no effective therapy to cure this disease exists.

Parkinson's disease affects people between 50 and 70 years old. The primary damage consists of a progressive atrophy of the black substance of neuron cells and a resulting degeneration of dopaminergic systems. The three main symptoms are: trepidations, holotonia and akinesia. The known therapies comprise an inhibiting factor of the cholinergic system.

SUMMARY OF THE INVENTION

It has now unexpectedly been found, and this constituted the starting point of the present invention, that conditions of the central nervous system and the endocrine system associated with anxiety and/or depression may be efficiently treated by administration of anti-melitensis vaccine in quite low doses, generally corresponding to about 1/5 to about 1/250 of the doses conventionally used and effective for antibrucellosis therapy. This vaccine is known and has been used for some time for the prevention of the disease known as brucellosis or melitensis fever.

One aspect of the invention is a pharmaceutical composition having activity against depression, anxiety, multiple sclerosis, Alzheimer's disease and Parkinson's disease, containing as the active ingredient microorganisms of the Brucella genus.

Another principal aspect of the invention is the use of microorganisms of the Brucella genus or derivatives thereof for the manufacture of a pharmaceutical composition for the treatment (other than for the treatment or prevention of brucellosis) of depression, anxiety, multiple sclerosis, Alzheimer's disease and Parkinson's disease. The invention furthermore relates to and proposes a method of treatment of a human affected by the above mentioned diseases which consists in administering to said human microorganisms of the Brucella genus at doses which correspond generally to about 1/5 to about 1/250 of the doses of the microorganism conventionally used and effective for antibrucellosis therapy.

In some embodiments , at least one non-attenuated or substantially non-attenuated strain of Brucella melitensis, Brucella abortus and Brucella suis (sometimes also called Brucella intermedia) is used, particularly a combination of at least two different strains of Brucella melitensis, Brucella abortus and Brucella suis. A preferred combination of these three microorganisms contains 1-10 parts of Brucella melitensis, 1-10 parts of Brucella abortus and 1-10 parts of Brucella suis, based on the number of cells of the microorganisms.

However, attenuated microorganisms and their derivatives , such as the phenol-insoluble fraction of delipidated Brucella microorganisms, advantageously the phenol-insoluble fraction of delipidated Brucella abortus, preferably strain Buck 19, will sometimes be preferred.

The microorganisms are usually contained in a plurality of phials , for example in a series containing a progressively increasing number of cells.

The microorganisms are usually contained in a pharmaceutically sterile preservant liquid, i.e. an inert excipient alone or combined with a pharmaceutically active material. One embodiment comprises at least one non-attenuated or substantially non-attenuated strain of Brucella melitensis, Brucella abortus and Brucella suis in a series of phials containing a progressively increasing number of cells, the series beginning with at least one phial containing about 20 million cells of said microorganisms at most, the last phial of the series containing about 2000 million cells at most.

More specifically, in a ten-phial series the 1st and 2nd phials could contain 2-10 million cells each; the 3rd phial 5-20 million cells; the 4th phial 10-50 million cells; the 5th phial 20-100 million cells; the 6th phial 40-200 million cells; the 7th phial 50-300 million cells; the 8th phial 75-400 million cells; the 9th phial 100-500 million cells; and the 10th phial 200 million to 2000 million cells.

Excellent results with the above embodiments are obtained with a combination of non attenuated or substantially non-attenuated microorganisms containing 1-10 parts of Brucella melitensis, 1-10 parts of Brucella abortus and 1-10 parts of Brucella suis, based on the number of cells of the microorganisms, and particularly when these components are in the ratio of about 1:1:3.

When attenuated microorganisms such as the phenol-insoluble fraction of delipidated Brucella, are used, they can be contained in a series of phials containing a progressively increasing quantity of the fraction. For example, the series consists of four to ten phials, the series beginning with at least one phial containing from about 2 to about 20 meg (microgramε) of said fraction, the last phial of the series containing from about 6 to about 60 meg of said fraction.

The above-indicated contents of the series of phials expressed as the number of cells (or micrograms of fraction) per phial can obviously be varied as a function

5 of the activity (degree of attenuation) of the microorganisms which will determine the dosage necessary to provide the required improvement without unwanted reactions, and the number of doses that may be contained in each phial. In order to avoid the possibility of

10 inadvertent injection of an overdose that could cause ^'an unwanted reaction, at least the first phials of the series should preferably not contain multiple doses the total amount of which, if inadvertently administered in one injection, could lead to such a reaction.

15. Phials containing larger doses of the microorganisms may be obtained by using a suitable dilution. In this case, the concentration expressed as the number of cells (respectively micrograms) per millilitre of solution should not exceed the number of cells (respectively

20 micrograms) stated above. In other words, the figure given above as the number of cells (micrograms) per phial corresponds to the equivalent concentration in cells/ml (mcg/ml) for those cases where the phial contains more than that number of cells (mcg/ml) .

25 One available vaccine against brucellosis in humans contains strains of Brucella melitensis, Brucella abortus bovis, Brucella suis in the ratio of 1:1:3. This vaccine is commercialized by the Istituto Biochimico Sardo (IBS) , Cagliari, and consists (for the normal brucellosis

30 therapy) of a series of 10 phials each of 1 ml characterized by increas ing amounts of bacteria , for example : the first and second phials contain 25 million cells/ml; the third contains 50 million/ml; the fourth contains 100 million/ml; the fifth contains 250 million/ml; the sixth contains 500 million/ml; the seventh contains 1000 million/ml; the eighth contains 1500 million/ml; the ninth contains 2000 million/ml.

Another known vaccine for human use contains only the phenol-insoluble fraction of delipidated Brucella abortus. This vaccine, as commercially available from the Institut Merieux of Lyon, consists of a suspension of 1 mg of the phenol-insoluble fraction of Brucella abortus (strain Buck 19) in 0.5 ml of an aqueous solution containing, per liter, 8.5 g of sodium chloride, 0.5672 g of NaH PO .2H O, 2.5 g of NaH PO .12H 0 and 5 g of phenol as preserving agent. This vaccine is prepared according to French patent No. 2.506.615 through delipidation (for example with alcohol/ether) of entire Brucella abortus bacteria, collecting the solid fraction obtained, submitting it - after drying - to extraction with phenol (preferably with water-saturated phenol at a temperature of about 60^βC) , washing firstly with alcohol, then with ether, the phenol-insoluble filtered product, and preparing from such a product a homogeneous suspension sterilized at 120^βC for about 10 minutes.

Patients suffering from brucellosis often present symptoms of anxiety and depression, but treatments using the vaccine in the prescribed doses have not been found to improve the associated anxiety and depression and in some cases have made it worse.

Although the mechanism by which Brucella microorganisms administered - according to this invention - in low doses produce the new effect is not yet fully understood, continued research has established that these microorganisms appear to act as a non-specific stimulant on the central nervous system. The maximum permissible doses that will provide the new therapeutic effect without undesirable side effects has not yet been determined systematically. Nevertheless, it seems evident that these can be determined by a series of tests and, in any event, for obvious reasons, in practice the selected doses will be well below such threshold values. Also, the effective dosage for any given case will depend on the patient's weight, blood volume, blood analysis and so on. The dosages given in the following examples should thus be taken as indicative of working values that may still be optimized; they should not at this stage be regarded as defining the boundaries of operability of the invention.

In the case of the IBS vaccine it has been found useful for the new tfferapeutic applications to administer the antimelitensis vaccine by intramuscular injection, each 2-3 days, normally however, in the range of 0.01 to 0.2 ml of the commercially available phials (1 phial = 1 ml) in increasing concentrations, that is utilizing the phials in the same order containing increasing amounts of microorganisms. In other words, the administered effective doses are substantially about 1/100 to about 1/5 less than the doses recommended for anti-melitensis therapy. Larger and smaller doses than those mentioned have also been administered but, for most of the treated cases, the choice has been 0.1 ml (i.e. = 1/10) of the commercially available phials, taking into account that lesser concentrations may be less efficient or may necessitate a greater number of applications and increased concentrations would not increase the efficiency and could have resulted in secondary local reactions. It is understood that the dosage has to remain well below the corresponding dosage threshold above which secondary reactions, for example fever and the like, occur. (It is because of such reactions that vaccination against brucellosis is generally not recommended and is not widely practiced. However, with the dosages adopted according to the invention, no significant secondary reactions have ever been observed, apart from occasional minor occurences which do not interfere with the treatment) .

The treatment according to the invention is therefore carried out for example every 2 to 3 days, according to the following list and using 0.2 ml of each phial of the IBS vaccine: 1st administration corresponding to 5 million cells 2nd administration corresponding to 5 million cells 3rd administration corresponding to 10 million cells 4th administration corresponding to 20 million cells 5th administration corresponding to 50 million cells 6th administration corresponding to 100 million cells 7th administration corresponding to 200 million cells 8th administration corresponding to 300 million cells 9th administration corresponding to 400 million cells 10th administration corresponding to 400 million cells In the case of the vaccine from Institute Merieux, it has been found useful for the therapy according to the present invention, to dilute the phial (containing the suspension of 1 mg of the phenol-insoluble fraction of Brucella abortus in 0.5 ml of the specified solution); with a physiological solution to a final volume of 3.5 ml ("Dilution I") containing about 285 meg (micrograms) of phenol-insoluble fraction of Brucella abortus per ml. Furthermore 0.5 ml of "Dilution I" obtained in this way are again diluted - once more with a physiological solution - to a final volume of 3.5 ml ("Dilution II¹') containing about 40 mcg/ml of said fraction. In relation to the original suspension of the vaccine, the result is that "Dilution I" contains, for a given volume, a quantity of vaccine that is 7 times lower. "Dilution II" contains also for a given volume a quantity of vaccine about 50 times lower. Excellent results have been obtained when for example this vaccine was administered every 2 to 3 days by intramuscular injection, according to the following list, using "Dilution II": 1st administration: 0.1 ml (about 4 meg of PIFBA*) 2nd administration: 0.1 ml (about 4 meg of PIFBA*) 3rd administration: 0.1 ml (about 4 meg of PIFBA*)

4th administration: 0.15 ml (about 6 meg of PIFBA*) 5th administration: 0.15 ml (about 6 meg of PIFBA*) 6th administration: 0.15 ml (about 6 meg of PIFBA*)

7th administration: 0.20 ml (about 8 meg of PIFBA*) 8th administration: 0.20 ml (about 8 meg of PIFBA*) 9th administration: 0.20 ml (about 8 meg of PIFBA*) 10th administration: 0.20 ml (about 8 meg of PIFBA*) * = Phenol-Insoluble Fraction of Brucella Abortus

For injections of over 8 meg of PIFBA, if needed, Dilution I is used. The obtained results, also with this treatment and these doses, have been excellent, giving to all patients a considerable improvement and in almost all cases an almost complete recovery according to the indications of the tables compiled by the patients. In general, it can be said that already after the first few administrations evident signs of improvement can be observed by the patient, but generally the treatment is completed according to the indicated lists and sometimes also by increasing the dose or the concentration. For instance, in many cases treatment with the Institut Merieux vaccine could already be considered complete after only six administrations. In a few other cases, if a complete recovery had not been achieved after 10 administrations, the treatment was continued by injecting two or three more times using "Dilution I".

The invention, however, is not limited to the above-mentioned therapeutic schemes because it can be foreseen that other ways of administration with respect to the method of application, dosage, frequency and pharmaceutical forms, should lead to the same results. Therefore, the dosages described in the example mentioned above for the IBS type vaccine (which correspond to 1/5 of the dose recommended for brucellosis vaccination therapy) could be even less (for example 1/20) or greater (for example 1/3) than the dose recommended for anti-brucellosis vaccination, while the treatment with the vaccine of the Institut Merieux may be effected with 2-8 meg of PIFBA in the lst-3th administrations, with 4-12 meg in the 4th-6th, administrations and with 6-30 meg in the subsequent administrations.

Also the intervals between one administration and another can be increased and it has been noted that this is advisable especially if the injected doses are increased with regard to those found most advisable for the therapy according to the present invention which foresees, for _. some diseases of the nervous system,the possibility to use concentrations , intervals and number of administration very different from case to case. As a general rule, nearly all patients treated to date have shown signs of a complete recovery after a single series of administrations according to the above dosage schemes. However, with a very small number of patients it was found useful to repeat the treatment after about 6 months to one year. For these cases, a recall treatment, at set periods of for example one year or whenever further treatment needs to be prescribed, ^' is beneficial. The dosage for recall treatments can be the same as or different from the initial amount injected and/or the number of injections; often a medium dosage will be selected.

The synergistic effect of the anti-melitensis vaccine in combination with other curative products is surprising and efficient. Such products may be administered separately during the treatment, or in some cases can be combined with the Brucella microorganisms. The additional products may enhance the curative effect of the vaccine, or may for example reduce or inhibit side effects, e.g. fever. Thus, in addition to the vaccines already commercially available, pharmaceutical compositions prepared purposely to be used against anxiety and as anti-depressants, also fall within the scope of the present invention, i.e. pharmaceutical compositions which contain for instance selected strains of Brucella in a predetermined dosage. The preparation of such pharmaceutical compositions is carried out according to known and conventional methods such as described in for instance Remington's Pharmaceutical Science Handbook, Hack Pub. Co. New York U.S.A.

It is also possible to combine the Brucella micro¬ organisms with other microorganisms, for example vaccines which are known for the treatment of other diseases, especially attenuated forms of such microorganisms. In addition to diluted forms of commercially available vaccines, the same new therapeutic effect may be obtained with derivatives of the known vaccines or with derivatives or modifications of Brucella micro¬ organisms produced by known methods, i.e. including known techniques for killing or partially killing the bacteria, and for separating specific fractions thereof.

CLINICAL TEST PROCEDURES

The following procedures were followed in a series of tests for patients suffering from anxiety and/or depression and other nervous-related disorders. First, the patient's general psychic state is evaluated (with due regard to the fact . that patient's statements are of en exaggerated) , and a general semiologic investigation performed. Then, the patient is asked to compile a self-evaluation schedule, avoiding any outside interference.

In these tests schedules are used for the autoevaluation of anxiety and depression just before the therapy and immediately afterwards. The scale of anxiety is an adaptation of the - "Anxiety Rating Scale" of Hamilton; this scale is known as SAS index (Symptoms of Anxiety Scale) . A global value above 20 is considered an expression of anxiety.

The scale of autoevaluation of depression used is the scale of Zung (SDS, Self Depression Scale) , according to which patients are classified as follows: individuals who are not depressed, or on the borderline, between 20 and 29; individuals who are anxious and depressed, between 30 and 42; individuals with moderate depression, between 43 and 59; individuals with serious depression, between 60 and 80.

Also, the patient's thyroid function is checked because the treatment according to the invention does not have the same surprising effect for states of anxiety due to thyroid malfunction.

If the patient has already been taking medication to treat the psychic disorder, the product(s) used, their dosage and duration of the treatment are noted. When the treatment according to the invention is started, the previous treatments can be stopped, abruptly in the case of benzodiazepines, but gradually and carefully for other products, in order to avoid rebound phenomena or slowing or reducing the action of the treatment according to the invention.

It is also verified whether or not the patient is affected at that time by a viral or bacterial infection.

If so, the therapy can still be performed but the patient should be treated with an antibiotic of the amoxicillin type for instance at 2 g per day for five to six days.

It is not necessary to perform a reaction test prior to the treatment, because the treatment uses highly diluted doses of the microorganisms and the therapy is still valid even if there is a slight initial reaction after the first injection(s) .

The usual treatment consists of a series of ten intramuscular injections in the deltoid area, one every two or three days, of small calibrated doses of the Brucella-based vaccine as specified above. Other administration methods are possible, for example skin scarification.

The treatment can be stopped as soon as a clear improvement appears. This happens very often after five or six injections. Should an improvement after the first five or six injections appear to be sluggish, the treatment can be pursued combined with the administration

TM of L-Sulpirid twice a day and magnesium-based remedies for five to six days. A typical evolution of the treatment and its progress is as follows. The patients initial response is noted and possible minor local reactions are checked after the second injection. The first signs of improvement usually appear after the third injection, especially with patients previously under treatment with other products. The general response can and preferably is evaluated after the fourth injection. Most patients voluntarily express feelings of satisfaction and well being after the 5th injection. From the 6th to 10th injections normally a marked improvement should continue and become stable. If, however, the improvement does not progress as desired, higher doses can then be used, as set out above. Generally speaking, further increase of the dosage is not dangerous but will not improve the effect.

In the event (which so far has been rare) that no improvement is noticed during the therapy, the treatment should be stopped and resumed after 30 days.

At the end of the treatment, the patients compile new Hamilton and Zung rating scales for comparison with the initial ones.

It can sometimes be useful, depending on the state of the patient, to repeat a partial or complete series of injections after 6 months. For the Institut Merieux vaccine, this can be done using the normal 1 ml dose (4 meg of PIFBA) with five to ten injections at two or three days interval.

CLINICAL TEST RESULTS

By way of example there are reported hereinbelow the clinical results obtained by utilizing the above-mentioned commercial vaccines according to the schedule of treatment described above for the treatment of states associated with anxiety and depression, followed by the results for other nervous-related disorders .

The following tables report some clinical cases of anxiety and depression which are among the most significant. For each patient, sex, age, and the scale of autoevaluation are indicated. The results given are only a small portion of all cases available at present and all the cases are characterized by a high percentage of success, that is a clinically complete recovery which is particularly high. Besides, in about two thirds of the cases a considerable improvement was noted already after the first injections.

Table I gives results obtained with the IBS type vaccine according to the first dosages specified above. Similarly, Table II gives results obtained with treatments using the Merieux type vaccine with the second dosage scheme given above. TABLE I

Treatment with IBS Vaccine

TABLE II

Treatment with Institut Merieux Vaccine

(continued) TABLE II (cont.)

The results reported in the tables are even more surprising, since complete improvements have been ma_de also with those patients suffering from forms of anxiety and/or depression that had not responded to treatments with conventional pharmacological agents. In order to exclude any placebo effect, comparative tests were carried out in which physiological fluid was administered by injection to some patients. None of these showed any substantial improvement but when the placebo was replaced by the treatment according to the invention, for nearly all patients there was a marked positive effect already after the first few injections, and all of them were clinically cured at the end of the treatment.

Largely favourable results have been obtained also in the treatment of a small number of patients affected by multiple sclerosis that received the treatment according to the invention by the administration of Institut Merieux type vaccine in the same doses and in the same manner as indicated above. There was a marked improvement, medically evaluated at 60%, not only in physical and moral depressive states, but also in motor disturbances .

The results of the treatment according to the invention with patients affected by Alzheimer's disease have been remarkable. To some of those patients, who had a marked malfunction of the intellectual and motor functions, vaccine of the Institut Merieux type was administered with the same dosage and in the same manner as mentioned above. For all patients a marked improvement, either of intellectual functions or of the coordination of movements, was obtained. For example, two of these patients have succeeded in writing in a perfectly intelligible manner, which they had not been able to do for a long time. A third patient reacquired full capacity to eat and drink alone. Moreover, the families of the patients noticed a surprising reinvolvement from the point of view of the patient's social relationships.

The cases of Parkinson's disease treated up to now by administration of the Institut Merieux type vaccine are encouraging by the improvements noted with the patients, but the number of cases treated have been too few to be able to produce conclusive statistics.

Considering the present day knowledge on the origin of the phenomenon of nervous related disorders as discussed at the outset, the surprising results obtained with the pharmaceutical compositions used according to the invention are probably attributed to an action mechanism which involves the central nervous system, the endocrine system and the immune system.

The invention is based on the fact that anti-melitensis vaccine administered in low doses has been identified as a powerful stimulator of the immune system in general which influences the state of the nervous system and, furthermore, has a synergistie effect in the cure of disorders either of the nervous system or of the immune system or of the endocrine system alone or in combination with known pharmaceuticals. Obviously the exact interpretation of the mechanism of action of the claimed pharmaceutical composition does not constitute a factor limiting the scope of the invention.

Claims

1. Use of microorganisms of the Brucella genus or derivatives thereof for the manufacture of a pharmaceutical composition for the treatment (other than for the treatment or prevention of brucellosis) of depression, anxiety, multiple sclerosis, Alzheimer's disease and Parkinson's disease.

2. Use according to claim 1, of one or more strains of Brucella melitensis, Brucella abortus and Brucella suis.

3. Use according to any one of the preceding claims of the phenol-insoluble fraction of delipidated Brucella microorganisms.

4. Use according to claim 3, wherein the microorganisms include the phenol-insoluble fraction of delipidated

Brucella abortus , preferably strain Buck 19.

5. Use according to any one of claims 1 to 4, wherein the microorganisms are contained in a first series of phials each containing the same number of cells, a second series of phials each containing a greater number of cells than the phials of the first series, and a third series of phials containing a greater number of cells than the phials of the second series.

6. Use according to any one of the preceding claims, wherein the microorganisms are contained in a pharmaceutically sterile preservant liquid alone or combined with a pharmaceutically active material.

7. A pharmaceutical composition for treatments as defined in claim 1 containing as active ingredient microorganisms of the Brucella genus or derivatives thereof, in doses from about 1/5 to about 1/250 of the doses recommended for anti-melitensis therapy.

8. The pharmaceutical composition of claim 7 comprising at least one non-attenuated or substantially non-attenuated strain, preferably a combination of at least two different strains, of Brucella melitensis, Brucella abortus and Brucella suis in a series of phials containing a progressively increasing number of cells, the series beginning with at least one phial containing about 20 million cells of said microorganisms at most, the last phial of the series containing about 2000 million cells at most.

9. The pharmaceutical composition of claim 8, wherein the series is made up of at least six phials containing the microorganisms in the following amounts:

- 1st, 2nd and 3rd phials, about 2 to about 20 million cells each;

- 4th, 5th and 6th phials, about 10 to about 500 million cells each, preferably about 20 to about 200 million cells each; and

- the 7th and each subsequent phial, if any, about 50 to about 2000 million cells each, preferably about 200 to about 800 million cells.

10. A pharmaceutical composition for treatment as defined in claim 1 comprising the phenol-insoluble fraction of delipidated Brucella microorganisms, in a series of phials containing a progressively increasing quantity of said fraction, the series beginning with at last one phial containing 8 micrograms of said fraction at most, the last phial of the series containing about 60 micrograms of said fraction at most.

11. The pharmaceutical composition of claim 10 wherein the series is made up of at least six phials containing the microorganisms in the following amounts:

- 1st, 2nd and 3rd phials, about 2-6 micrograms;

- 4th, 5th and 6th phials, about 4-12 micrograms;

- the 7th and each subsequent phial, if any, about 6-30 micrograms.

12. A method of treatment of a human affected by depression, anxiety, Alzheimer's disease or Parkinson's disease, which consists in administering to said human microorganisms of the Brucella genus, or derivatives thereof, in doses from about 1/5 to about 1/250 of the doses normally recommended for anti-melitensis therapy.

13. Method according to claim 12, wherein one or more strains of Brucella melitensis, Brucella abortus and Brucella suis are administered.

14. Method according to claim 12, wherein a phenol-insoluble fraction of delipidated Brucella microorganism is administered.

15. Method according to claim 12, wherein the phenol-insoluble fraction of delipidated Brucella abortus, strain Buck 19, is administered.