user18930: I had rather severe melancholia for some time and I still feel deep despair occasionally.
For example, today, just after the workout and a good meal, I felt severe, yet inexplicable, mental suffering. No one offended me or anything bad happened recently, but I could not relax or concentrate on something. I just felt anger (not to anyone particular), self-pity and deep dissatisfaction. I wanted to pop tranquillizer firstly but instead decided just to sit down and practice open-monitoring meditation. I cried a bit, but these feelings have largely gone and I feel calmer now (though not happy for sure).
Every day I feel this subtle dissatisfaction and it often progresses to those hysterical outbreaks (uncharacteristic for males, I know). Despite that, I feel mostly drowsy during the day, not nervous, but this is quite another problem for which I think meditation on breath is the main solution, as it helps you stay awake and more concentrated.
Is open-monitoring meditation the best idea when you feel you are about to cry? I thought about Metta meditation, too, but wishing yourself or anyone else happiness sounds like a joke during those outbreaks. I often practice Metta before sleep though.
So what would you recommend on preventing and "treating" these hysterical reactions? You know, psychiatrists and psychologists have nothing to offer to deal with it, except for the drugs...

user16297: Good exercise and healthy diet daily. When the body is healthy, it's a lot easier to tame the mind. Follow the Mayo clinic guideline for recommended daily amount of exercise. 

user-1: Samana Johan gave a good answer,do that. 
Furthermore get some admirable friends, do not associate with shitty people. Good company in definitive sense is all of the holy life. No friendship with fools.
I will add that Buddha praised giving gifts, he also told householders to not be content having provided gifts to the Sangha but to also attain 'seclusion'.

Lord, when a disciple of the noble ones enters & remains in seclusion & rapture, there are five possibilities that do not exist at that time: The pain & distress dependent on sensuality do not exist at that time. The pleasure & joy dependent on sensuality do not exist at that time. The pain & distress dependent on what is unskillful do not exist at that time. The pleasure & joy dependent on what is unskillful do not exist at that time. The pain & distress dependent on what is skillful do not exist at that time. When a disciple of the noble ones enters & remains in seclusion & rapture, these five possibilities do not exist at that time."

It does not need to be a 'deep meditative state'. Ie if one thinks about virtue, the buddha, one's good deeds it can be accompanied by gladness and be quite pleasant.
These states at that time are secluded from the five things that don't exist at that time.
You could try finding themes of ideas to entertain which work to seclude by directing elsewhere.

"Whatever a monk keeps pursuing with his thinking & pondering, that becomes the inclination of his awareness. If a monk keeps pursuing thinking imbued with sensuality, abandoning thinking imbued with renunciation, his mind is bent by that thinking imbued with sensuality. If a monk keeps pursuing thinking imbued with ill will, abandoning thinking imbued with non-ill will, his mind is bent by that thinking imbued with ill will. If a monk keeps pursuing thinking imbued with harmfulness, abandoning thinking imbued with harmlessness, his mind is bent by that thinking imbued with harmfulness.

This is how it comes about. 
When one trains ie mindfulness of breathing, it's also called 'perception of in and out breaths'. 
One can basicly sit perceiving the in and out breaths. One can contemplate their cessation and impermanence, at that time one's theme is also impermanence and one trains perception of impermanence.
One should be mindful of the arising, the persisting and the passing away in regards to feelings and perceptions.
If mind is not easily calmed by the perception of in ans out breathing, one should direct the mind to a different theme. There are too many to list, i have a list tho;
https://docs.google.com/document/d/1kZxstsAvjhj9Svc47RUKRIyKQMuHMD4adIvr_7pp2uI/edit?usp=drivesdk

Sluggish/Tired Mind
"At such times, monks, as the mind is sluggish, that is the wrong time to cultivate the enlightenment-factor[1] of tranquillity, the enlightenment-factor of concentration, the enlightenment-factor of equanimity. What is the reason? A sluggish mind is hard to arouse by these factors.
  "But, monks, when the mind is sluggish, that is the right time to cultivate the enlightenment-factor of investigation-of-states, the enlightenment-factor of energy, the enlightenment-factor of rapture.[2] What is the reason? A sluggish mind is easy to arouse by these factors.

Aroused/Active/Agitated Mind

"Monks, when the mind is agitated,[3] that is the wrong time to cultivate the enlightenment-factors of investigation-of-states, of energy, of rapture. Why? An agitated mind is hard to calm through these factors.
  "When the mind is agitated, that is the right time to cultivate the enlightenment-factors of tranquillity, concentration, equanimity. Why? Because an agitated mind is easy to calm[4] through these factors.

Buddha definitely taught directing the mind;

“There is the case of a monk who remains focused on the body in & of itself—ardent, alert, & mindful—subduing greed & distress with reference to the world. As he remains thus focused on the body in & of itself, a fever based on the body arises within his body, or there is sluggishness in his awareness, or his mind becomes scattered externally. He should then direct his mind to any inspiring theme. As his mind is directed to any inspiring theme, delight arises within him. In one who feels delight, rapture arises. 
In one whose mind is enraptured, the body grows calm. His body calm, he feels pleasure. As he feels pleasure, his mind grows concentrated. 
He reflects, ‘I have attained the aim to which my mind was directed. Let me withdraw [my mind from the inspiring theme].’ He withdraws & engages neither in directed thought nor in evaluation. He
  discerns, ‘I am not thinking or evaluating. I am inwardly mindful & at ease.’
“This, Ananda, is development based on directing. 
And what is development based on not directing? A monk, when not directing his mind to external things, discerns, ‘My mind is not directed to external
  things. It is unconstricted [asankhitta] front & back—released & undirected. And then, I remain focused on the body in & of itself. I am ardent, alert, mindful, & at ease.’
“When not directing his mind to external things, he discerns, ‘My mind is not directed to external things. It is unconstricted front & back—released & undirected. And then, I remain focused on feelings… mind… mental qualities in & of themselves. I am ardent, alert, mindful, & at ease.’ 
“This, Ananda, is development based on not directing.

If want to read more details on meditation and overcoming hindrances;
https://docs.google.com/document/d/1hRy-g6o8yKsDQnR6_sbBbY5ZVpDbQ5-_LURXqwxS7YU/edit?usp=drivesdk
You should separate your thoughts categorically as to whether they are associated with desire,anger or delusion; or not associated.
Then you start actively calming the bad ones as instructed here;
https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html
https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html

user254: For example, today, just after the workout and a good meal, I felt severe, yet inexplicable, mental suffering.
I usually have trouble after a meal, I don't know why.
So I tend to take a nap or go to sleep then.
I'm not saying that's especially Buddhist, just that's my experience of what happens and how I cope.
I wanted to pop tranquillizer firstly
So I guess you have a psychiatric prescription for a mood-altering drug.
I don't know what to say about that, I don't want to contradict your psychiatrist.
Conventional wisdom is that psychiatric drugs can be effective, even necessary -- but have side-effects too, and so it can be difficult or dangerous to stop using them or to keep on using them.
Basically your prescription is outside my experience, it may be a factor but it's not to be discussed here.
Is open-monitoring meditation the best idea when you feel you are about to cry?
The last time I went through a period of crying often, there was a cause or trigger (i.e. someone close to me had died).
The best cure for that I found was the first three suttas, i.e.:

The four noble truths ("suffering arises when you want things to be other than as they are, and stops when craving stops")
The fire sermon ("sense-experiences are impermanent and attaching to them causes suffering")
The anatta sutta ("viewing the aggregates as 'self' is a source of suffering")

There are more suttas than just those three, but they addressed most of what ailed me -- attachment, craving, suffering, and self-pity.
Assuming that moments of suffering end (even if they keep repeating themselves) the question arises, "what to do instead of suffering?"
Now people can and do become monks for example, I assume that's to gain good teachers and an opportunity to practice full-time.
Apart from that (i.e. if you don't do that) I think that Buddhism has three bits of advice:

Some things are "necessities" of life (food, clothing, shelter, and IMO sleep and some exercise too). We're supposed to avoid "extremes", so keep up these healthy practices.
It's important to have a good friend -- someone who is wise, moral, self-controlled, skilful -- someone you can "depend" on, maybe gradually learn to be like them.
Some behaviours are moral and some are immoral -- moral behaviour, intending to help and to not hurt other people, doing the best you can, is behaviour which you don't end up regretting: "I'm glad I tried to do that, no remorse".

So trying to do moral things, to help other people (and yourself), is a basis or a foundation.
Anyway for me I guess the best idea is "recollecting the dhamma".
wishing yourself or anyone else happiness sounds like a joke during those outbreaks.
Maybe wishing for "non-suffering" or for the "cessation of suffering" or "liberation (from suffering)" makes sense.
One other possibility is to concentrate on current sensations as you become aware of sensing them (including sight, touch, hearing). One of the versions of the metta gatha is, "may I be safe from internal and external harm". If you've been traumatised by some past event it might be reassuring to be aware (to realise, to sense) that the traumatic event is not in fact still happening now.

user-1: Good householder. Just observe the precepts well and seriouse, change your livelihood and style so that this is possible and train yourself in generosity. Nonsens to try to fix here things by forced meditations. Metta, of course, is the base, right view, of all this simple training, good householder. From freedom of remorse, through keeping precepts, based on right view, the path develops on the given cources by "itself", including right conncentration, knowledge... insight of the destruction of effluents, followed by release from all suffering.
Silena sugati yanti,
Silena boghasampada,
Silena nibbutam yanti,
Tasma Silam vasodhaye.
Virtue leads to happiness, 
Virtue leads to wealth (incl. real wealth),
Virtue leads to Awakening, Nibbana,
This is why we should stick to them.
A good, generouse given read in addition: The Healing Power of the Precepts.
(Note: not given for trade, exchange, stackes, or other binders to the world but for liberation of this wheel)

user43: In the Buddhist system, your mood is a function of your position, a subjective universe you get yourself in. Three factors in your control are responsible for creating your universe, these are your karma, your attention, and your perspective.

Karma has inertia, it takes time and effort to get to a different place. More then anything, it takes a firm decision or determination.
Attention is faster way to control your mood. The world you construct in your mind is constructed from fragments you pick by attending to them. This consists of observations about the world as well as facts and opinions about yourself.
A lot of times the reason we feel sad or depressed is the cyclical going over all the problems we see in the world and in ourselves. It's almost like we take pride in maintaining ourselves in the traumatized condition. This harmful habit can and should be unlearned. 
The final part of the equation is your perspective, a set of expectations about how things are supposed to be, your basic frame of reference. If the fragments of your world (including your self-image) go against your "how things are supposed to be", then the overall state is evaluated as "wrong", and vice versa.
This allows another point of control, which is subtler and more powerful. Instead of shifting your attention entirely you change how you evaluate things.
For example, if you attend to true causes of things being the way they are, you will see that things actually are the way they are supposed to be, like the clouds morphing into their current configuration from their previous state, and on their way to next - then this picture of the world will be evaluated as "as it should be" - which is a happy state. 

The ultimate trick is to hold multiple perspectives at once which is akin to being simultaneously in multiple worlds. The end result of this is that you end up having no single position. Having no position, you are immune to bad mood and are mentally invincible.
A great way to spend the time you sit in meditation is to play with these factors until you gain some level of mastery over them. 

18930: <p>I had rather severe melancholia for some time and I still feel deep despair occasionally.</p>

<p>For example, today, just after the workout and a good meal, I felt severe, yet inexplicable, mental suffering. No one offended me or anything bad happened recently, but I could not relax or concentrate on something. I just felt anger (not to anyone particular), self-pity and deep dissatisfaction. I wanted to pop tranquillizer firstly but instead decided just to sit down and practice open-monitoring meditation. I cried a bit, but these feelings have largely gone and I feel calmer now (though not happy for sure).</p>

<p>Every day I feel this subtle dissatisfaction and it often progresses to those hysterical outbreaks (uncharacteristic for males, I know). Despite that, I feel mostly drowsy during the day, not nervous, but this is quite another problem for which I think meditation on breath is the main solution, as it helps you stay awake and more concentrated.</p>

<p>Is open-monitoring meditation the best idea when you feel you are about to cry? I thought about Metta meditation, too, but wishing yourself or anyone else happiness sounds like a joke during those outbreaks. I often practice Metta before sleep though.</p>

<p>So what would you recommend on preventing and "treating" these hysterical reactions? You know, psychiatrists and psychologists have nothing to offer to deal with it, except for the drugs...</p>
 16297: <p>Good exercise and healthy diet daily. When the body is healthy, it's a lot easier to tame the mind. Follow the Mayo clinic guideline for recommended daily amount of exercise. </p>
 -1: <p>Samana Johan gave a good answer,do that. </p>

<p>Furthermore get some admirable friends, do not associate with shitty people. Good company in definitive sense is all of the holy life. No friendship with fools.</p>

<p>I will add that Buddha praised giving gifts, he also told householders to not be content having provided gifts to the Sangha but to also attain 'seclusion'.</p>

<blockquote>
  <p>Lord, when a disciple of the noble ones enters &amp; remains in seclusion &amp; rapture, there are five possibilities that do not exist at that time: The pain &amp; distress dependent on sensuality do not exist at that time. The pleasure &amp; joy dependent on sensuality do not exist at that time. The pain &amp; distress dependent on what is unskillful do not exist at that time. The pleasure &amp; joy dependent on what is unskillful do not exist at that time. The pain &amp; distress dependent on what is skillful do not exist at that time. When a disciple of the noble ones enters &amp; remains in seclusion &amp; rapture, these five possibilities do not exist at that time."</p>
</blockquote>

<p>It does not need to be a 'deep meditative state'. Ie if one thinks about virtue, the buddha, one's good deeds it can be accompanied by gladness and be quite pleasant.</p>

<p>These states at that time are secluded from the five things that don't exist at that time.</p>

<p>You could try finding themes of ideas to entertain which work to seclude by directing elsewhere.</p>

<blockquote>
  <p>"Whatever a monk keeps pursuing with his thinking &amp; pondering, that becomes the inclination of his awareness. If a monk keeps pursuing thinking imbued with sensuality, abandoning thinking imbued with renunciation, his mind is bent by that thinking imbued with sensuality. If a monk keeps pursuing thinking imbued with ill will, abandoning thinking imbued with non-ill will, his mind is bent by that thinking imbued with ill will. If a monk keeps pursuing thinking imbued with harmfulness, abandoning thinking imbued with harmlessness, his mind is bent by that thinking imbued with harmfulness.</p>
</blockquote>

<p>This is how it comes about. </p>

<p>When one trains ie mindfulness of breathing, it's also called 'perception of in and out breaths'. </p>

<p>One can basicly sit perceiving the in and out breaths. One can contemplate their cessation and impermanence, at that time one's theme is also impermanence and one trains perception of impermanence.
One should be mindful of the arising, the persisting and the passing away in regards to feelings and perceptions.</p>

<p>If mind is not easily calmed by the perception of in ans out breathing, one should direct the mind to a different theme. There are too many to list, i have a list tho;
<a href="https://docs.google.com/document/d/1kZxstsAvjhj9Svc47RUKRIyKQMuHMD4adIvr_7pp2uI/edit?usp=drivesdk" rel="nofollow noreferrer">https://docs.google.com/document/d/1kZxstsAvjhj9Svc47RUKRIyKQMuHMD4adIvr_7pp2uI/edit?usp=drivesdk</a></p>

<blockquote>
  <p>Sluggish/Tired Mind</p>
  
  <p>"At such times, monks, as the mind is sluggish, that is the wrong time to cultivate the enlightenment-factor[1] of tranquillity, the enlightenment-factor of concentration, the enlightenment-factor of equanimity. What is the reason? A sluggish mind is hard to arouse by these factors.
  "But, monks, when the mind is sluggish, that is the right time to cultivate the enlightenment-factor of investigation-of-states, the enlightenment-factor of energy, the enlightenment-factor of rapture.[2] What is the reason? A sluggish mind is easy to arouse by these factors.</p>
</blockquote>

<p>Aroused/Active/Agitated Mind</p>

<blockquote>
  <p>"Monks, when the mind is agitated,[3] that is the wrong time to cultivate the enlightenment-factors of investigation-of-states, of energy, of rapture. Why? An agitated mind is hard to calm through these factors.
  "When the mind is agitated, that is the right time to cultivate the enlightenment-factors of tranquillity, concentration, equanimity. Why? Because an agitated mind is easy to calm[4] through these factors.</p>
</blockquote>

<p>Buddha definitely taught directing the mind;</p>

<blockquote>
  <p>“There is the case of a monk who remains focused on the body in &amp; of itself—ardent, alert, &amp; mindful—subduing greed &amp; distress with reference to the world. As he remains thus focused on the body in &amp; of itself, a fever based on the body arises within his body, or there is sluggishness in his awareness, or his mind becomes scattered externally. He should then direct his mind to any inspiring theme. As his mind is directed to any inspiring theme, delight arises within him. In one who feels delight, rapture arises. </p>
  
  <p>In one whose mind is enraptured, the body grows calm. His body calm, he feels pleasure. As he feels pleasure, his mind grows concentrated. </p>
  
  <p>He reflects, ‘I have attained the aim to which my mind was directed. Let me withdraw [my mind from the inspiring theme].’ He withdraws &amp; engages neither in directed thought nor in evaluation. He
  discerns, ‘I am not thinking or evaluating. I am inwardly mindful &amp; at ease.’</p>
  
  <p>“This, Ananda, is development based on directing. </p>
  
  <p>And what is development based on not directing? A monk, when not directing his mind to external things, discerns, ‘My mind is not directed to external
  things. It is unconstricted [asankhitta] front &amp; back—released &amp; undirected. And then, I remain focused on the body in &amp; of itself. I am ardent, alert, mindful, &amp; at ease.’</p>
  
  <p>“When not directing his mind to external things, he discerns, ‘My mind is not directed to external things. It is unconstricted front &amp; back—released &amp; undirected. And then, I remain focused on feelings… mind… mental qualities in &amp; of themselves. I am ardent, alert, mindful, &amp; at ease.’ </p>
  
  <p>“This, Ananda, is development based on not directing.</p>
</blockquote>

<p>If want to read more details on meditation and overcoming hindrances;
<a href="https://docs.google.com/document/d/1hRy-g6o8yKsDQnR6_sbBbY5ZVpDbQ5-_LURXqwxS7YU/edit?usp=drivesdk" rel="nofollow noreferrer">https://docs.google.com/document/d/1hRy-g6o8yKsDQnR6_sbBbY5ZVpDbQ5-_LURXqwxS7YU/edit?usp=drivesdk</a></p>

<p>You should separate your thoughts categorically as to whether they are associated with desire,anger or delusion; or not associated.</p>

<p>Then you start actively calming the bad ones as instructed here;
<a href="https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html</a></p>

<p><a href="https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html" rel="nofollow noreferrer">https://www.accesstoinsight.org/tipitaka/mn/mn.020.than.html</a></p>
 254: <p><strong>For example, today, just after the workout and a good meal, I felt severe, yet inexplicable, mental suffering.</strong></p>

<p>I usually have trouble after a meal, I don't know why.
So I tend to take a nap or go to sleep then.
I'm not saying that's especially Buddhist, just that's my experience of what happens and how I cope.</p>

<p><strong>I wanted to pop tranquillizer firstly</strong></p>

<p>So I guess you have a psychiatric prescription for a mood-altering drug.
I don't know what to say about that, I don't want to contradict your psychiatrist.
Conventional wisdom is that psychiatric drugs can be effective, even necessary -- but have side-effects too, and so it can be difficult or dangerous to stop using them or to keep on using them.
Basically your prescription is outside my experience, it may be a factor but it's not to be discussed here.</p>

<p><strong>Is open-monitoring meditation the best idea when you feel you are about to cry?</strong></p>

<p>The last time I went through a period of crying often, there was a cause or trigger (i.e. someone close to me had died).
The best cure for that I found was the first three suttas, i.e.:</p>

<ul>
<li>The four noble truths ("suffering arises when you want things to be other than as they are, and stops when craving stops")</li>
<li>The fire sermon ("sense-experiences are impermanent and attaching to them causes suffering")</li>
<li>The anatta sutta ("viewing the aggregates as 'self' is a source of suffering")</li>
</ul>

<p>There are more suttas than just those three, but they addressed most of what ailed me -- attachment, craving, suffering, and self-pity.</p>

<p>Assuming that moments of suffering end (even if they keep repeating themselves) the question arises, "what to do instead of suffering?"
Now people can and do become monks for example, I assume that's to gain good teachers and an opportunity to practice full-time.
Apart from that (i.e. if you don't do that) I think that Buddhism has three bits of advice:</p>

<ul>
<li>Some things are "necessities" of life (food, clothing, shelter, and IMO sleep and some exercise too). We're supposed to avoid "extremes", so keep up these healthy practices.</li>
<li>It's important to have a good friend -- someone who is wise, moral, self-controlled, skilful -- someone you can "depend" on, maybe gradually learn to be like them.</li>
<li>Some behaviours are moral and some are immoral -- moral behaviour, intending to help and to not hurt other people, doing the best you can, is behaviour which you don't end up regretting: "I'm glad I tried to do that, no remorse".</li>
</ul>

<p>So trying to do moral things, to help other people (and yourself), is a basis or a foundation.</p>

<p>Anyway for me I guess the best idea is "recollecting the dhamma".</p>

<p><strong>wishing yourself or anyone else happiness sounds like a joke during those outbreaks.</strong></p>

<p>Maybe wishing for "non-suffering" or for the "cessation of suffering" or "liberation (from suffering)" makes sense.</p>

<p>One other possibility is to concentrate on current sensations as you become aware of sensing them (including sight, touch, hearing). One of the versions of the <em>metta gatha</em> is, "may I be safe from internal and external harm". If you've been traumatised by some past event it might be reassuring to be aware (to realise, to sense) that the traumatic event is not in fact still happening now.</p>
 -1: <p>Good householder. Just observe the precepts well and seriouse, change your livelihood and style so that this is possible and train yourself in generosity. Nonsens to try to fix here things by forced meditations. Metta, of course, is the base, right view, of all this simple training, good householder. From freedom of remorse, through keeping precepts, based on right view, the path develops on the given cources by "itself", including right conncentration, knowledge... insight of the destruction of effluents, followed by release from all suffering.</p>

<p>Silena sugati yanti,
Silena boghasampada,
Silena nibbutam yanti,
Tasma Silam vasodhaye.</p>

<p>Virtue leads to happiness, 
Virtue leads to wealth (incl. real wealth),
Virtue leads to Awakening, Nibbana,
This is why we should stick to them.</p>

<p>A good, generouse given read in addition: <a href="http://accesstoinsight.eu/en/lib/authors/thanissaro/precepts" rel="nofollow noreferrer">The Healing Power of the Precepts</a>.</p>

<p><em>(Note: not given for trade, exchange, stackes, or other binders to the world but for liberation of this wheel)</em></p>
 43: <p>In the Buddhist system, your mood is a function of your position, a subjective universe you get yourself in. Three factors in your control are responsible for creating your universe, these are your karma, your attention, and your perspective.</p>

<ol>
<li><p>Karma has inertia, it takes time and effort to get to a different place. More then anything, it takes a firm decision or determination.</p></li>
<li><p>Attention is faster way to control your mood. The world you construct in your mind is constructed from fragments you pick by attending to them. This consists of observations about the world as well as facts and opinions about yourself.</p>

<p>A lot of times the reason we feel sad or depressed is the cyclical going over all the problems we see in the world and in ourselves. It's almost like we take pride in maintaining ourselves in the traumatized condition. This harmful habit can and should be unlearned. </p></li>
<li><p>The final part of the equation is your perspective, a set of expectations about how things are supposed to be, your basic frame of reference. If the fragments of your world (including your self-image) go against your "how things are supposed to be", then the overall state is evaluated as "wrong", and vice versa.</p>

<p>This allows another point of control, which is subtler and more powerful. Instead of shifting your attention entirely you change how you evaluate things.</p>

<p>For example, if you attend to true causes of things being the way they are, you will see that things actually <em>are</em> the way they are <em>supposed to be</em>, like the clouds morphing into their current configuration from their previous state, and on their way to next - then this picture of the world will be evaluated as "as it should be" - which is a happy state. </p></li>
</ol>

<p>The ultimate trick is to hold multiple perspectives at once which is akin to being simultaneously in multiple worlds. The end result of this is that you end up having no single position. Having no position, you are immune to bad mood and are mentally invincible.</p>

<p>A great way to spend the time you sit in meditation is to play with these factors until you gain some level of mastery over them. </p>
