It is one thing to see that taking SSRI medications can cause violence in some people, but quite another to make sense of it. In his blog, “Prescription-Only Violence”, Feb 18, 2013, David Healy identifies the three mechanisms through which these drugs can cause a person to do violent things:

“The antidepressants now come with black box warnings of suicide and in some jurisdictions such as Canada they come with warnings of violence also. Exactly the same mechanisms that lead to suicides lead to violence. In one case you have violence directed inward, and in the other directed outwards. These mechanisms are akathisia, emotional blunting and psychosis.”
It is important to recognize that there is overlap and interaction among these mechanisms in most people. Emotional blunting affects most people and akathisia is also fairly common. Psychosis occurs less frequently but it is not rare. It is very possible for a person to be affected by one or two or all three of these effects.
Mechanism #1 – Akathisia
“The mechanisms that lead a drug to cause suicide are the same that produce violence. The first of these is akathisia. Akathisia is a state of increased tenseness, irritability, restlessness, insomnia and a feeling of being intensely uncomfortable.”
This accurate description does not fully capture how terrible the experience of akathisia can be. The following comments were posted on the internet by people about their experience of akathisia:
“I feel like I have worms crawling under every inch of my skin.”
“I can’t stop squirming, so sleep/rest is impossible no matter how exhausted I am…”
“My mouth felt like I was sucking on a battery; tingling, electrical. The feeling of suffocation was worse; at the peak it felt like I was being burned alive. I couldn’t stop crying. I wanted to die, every fiber of my being wanted to be dead.”
“It was like a wave of sheer terror and panic. I would have done anything to make it stop.”
“has anybody experienced a sense of doom from their akathisia? When I get akathisia, it feels like it’s going to last forever and stay the same or get worse, that all that is or will be good for me has gone from the world.”
“It felt like someone close to me just died and I couldn’t stop crying. I’ve never felt such doom and hopelessness for no reason.”
“It was an anxiety so intense and deep seated I thought I was losing my mind.”
“but damn, akathisia is a living nightmare, makes everything else I’ve suffered from up till this point look like child’s play.”
“There’s no sense of DOOM and DARKNESS like what is felt during Akathisia. It’s inexplicable. I knew if I didn’t just die from it, I would kill myself if it didn’t let up. I was so sure I absolutely had to die. Because I could NOT STAND feeling that way one more minute.”
“Yesterday I had a strong urge to kill myself not because I want to die but because I want to kill myself.”
Perhaps the best description of all was put forward as a comment on the Aug 3 RxISK.org post The Man Who Thought he was a Monster: Antidepressants and Violence:

“the best description I have ever come across of why some people die by suicide which may go some way to help people understand- especially those angry, devastated and confused by the loss of a loved one to SSRIs – is by David Foster Wallace (who was treated for years with Nardil; some surmising that it may have been withdrawal from Nardil which led to his suicide):
“The so-called ‘psychotically depressed’ person who tries to kill herself doesn’t do so out of quote ‘hopelessness’ or any abstract conviction that life’s assets and debits do not square. And surely not because death seems suddenly appealing. The person in whom its invisible agony reaches a certain unendurable level will kill herself the same way a trapped person will eventually jump from the window of a burning high-rise. Make no mistake about people who leap from burning windows. Their terror of falling from a great height is still just as great as it would be for you or me standing speculatively at the same window just checking out the view; i.e. the fear of falling remains a constant. The variable here is the other terror, the fire’s flames: when the flames get close enough, falling to death becomes the slightly less terrible of two terrors. It’s not desiring the fall; it’s terror of the flames. And yet nobody down on the sidewalk, looking up and yelling ‘Don’t!’ and ‘Hang on!’, can understand the jump. Not really. You’d have to have personally been trapped and felt flames to really understand a terror way beyond falling.” “
In his book Medication Madness, Dr. Peter Breggin discusses akathisia under the title “A Painful Dance of Death.” He describes akathisia as “a drug-induced neurological disorder that is known to drive people to suicide and violence, and to madness”. He notes that “while studies of SSRI-induced akathisia vary greatly…the weight of evidence confirms that it is common.” He cites various estimates that range from 9.7 % of users to 25% of users. The intensity of the condition can range from discomfort to agony. In his book Brain-Disabling Treatments in Psychiatry, he states:
“Patients suffering from akathisia often use electrical metaphors or descriptions such as “electricity going through my veins” or “shocks in my head”. Words like excruciating, torture, and indescribable are commonly used. Patients often say they would rather die than live with akathisia… these individuals seen to be describing physical phenomena, as if they are being tortured from the inside out.”
Akathisia is a fairly common side effect of SSRI (and other) medications. In extreme cases it can cause such mental and physical agony that people are driven to do things they would not normally do.
Mechanism #2 – Emotional Blunting
“The next mechanism is emotional disinhibition, or blunting. This has been recognized by takers for a long time.”
Patients’ perception that taking SSRIs reduces their emotional engagement is supported by research. As early as 1990, a study at Johns Hopkins showed that taking SSRI antidepressants was associated with apathy and indifference. The degree of change was dose-dependent, and (at least for the 5 subjects in the study, all of whom took fluvoxamine [Luvox] or fluoxetine [Prozac] for less than one year) these undesirable effects dissipated with cessation of the medications.1
A 2009 qualitative study2 involving interviews of 38 patients found that “most participants described feeling emotionally detached or disconnected, and attributed this to their SSRI antidepressant.”
Some participants described being detached from their surroundings, and described feelings of being ‘ in limbo’, of ‘unreality’ or ‘ disconnection’ and of feeling as though they were a ‘ spectator’ rather than a participant…Some participants described feeling detached from their own emotions and instincts. ” Participants reported “a general reduction in the intensity of all the emotions that they experienced, so that all their emotions felt flattened or evened out, and their emotional responses to all events were toned down in some way. Very common descriptions of this phenomenon included feelings of emotions being ‘dulled’, ‘numbed’, ‘flattened’ or completely ‘blocked’, as well as descriptions of feeling ‘blank’ and ‘flat’. A few participants described a more extreme phenomenon, in which they did not experience any emotions at all.” Some subjects attributed helpful aspects to this numbing, such as improved emotional control, reduced tendency to overreact and reduced anxiety and worry. Many recognized that blunting might be a good thing in the very short run, but undesirable over the long term. They considered it a reason to discontinue the medication, along with another side usual effect, loss of sexual response and interest. Most participants reported feeling reduced sympathy and empathy, and described not caring about things that used to matter to them. They attributed this change to the SSRI antidepressant. They cared less about themselves, other people and the consequences of their actions. A few saw this disengagement as positive, while others recognized that it would cause difficulties for their loved ones.
The phenomenon of emotional blunting is described in detail in the excellent documentary series Who Cares in Sweden. In the first film, The Conscience, Dr. Dee Mangin explains that SSRI antidepressants can be helpful because they can remove the distress associated with the normal human emotions of sadness, worry and grief. At the same time, she warns:
“in removing the negative emotions, there is a trade-off. You also reduce the capacity for feeling love, affection and caring.”
In the same film, David Healy describes the phenomenon as “Care Less Syndrome” because when they take SSRIs, people care less about everything. He notes that this has enormous implications for relationships between spouses, parents and their children, friends, and society at large:
“when these drugs came on the market, we only looked at their effect on rating scales including items like sleep and anxiety and things like that. We didn’t check on the possible economic consequences. We didn’t look to issues like, do people lose their jobs because they aren’t as concerned about doing a good job as they had been before? Do their relationships break up? Do they have car accidents because they don’t take the usual amount of care?
…We know that people get “Care Less” on the drugs. You have to think that a proportion of those people will do things that they wouldn’t have done if they hadn’t been on the drugs, and which they will regret deeply afterwards.
Aside from the personal regret, there is a general issue for all of us: are contracts signed under the influence of these drugs valid contracts? Is a murder that is committed under the influence of a drug actually murder? Should the person who takes their own life while under the influence of a drug be regarded as having committed suicide, or not? Can they form the intent to kill themselves that people form when we consider it to be a valid suicide?
We do not have answers to these questions…”
One feature of this impairment in the case of SSRIs is that it often interferes with the user’s ability to notice the negative effect that the medications are producing.
SSRIs blunt emotions and the capacity for empathy, judgement and caring. In a state when a person feels detached from their own feelings, the strong emotional barriers (fear, self-preservation, caring about others) that normally act as a huge deterrent to acting on suicidal and aggressive urges are not as strong. This blunting combined with akathisia and impulsivity, may be the main way that SSRI antidepressants increase the risk of suicide. Combined with sudden rage and impulsivity, blunting is almost certainly one way in which these medications increase the risk for some people that they will harm others.
Mechanism #3: Delirium-Psychosis
According to David Healy:
“It is traditional to label the third factor in medication-induced violence psychosis but it would be more accurate to call it delirium. Delirium can be caused by fevers, diseases that affect the brain (e.g. cancer), internal toxins from liver disease, or external toxins in the form of medications. It is as if the person has an almost allergic response. The person can be completely “out of it” and experience hallucinations.
Two hundred years ago the only people who were considered “mad” were raving mad or frenzied – they were delirious. Everyone knew that people who were frenzied could be dangerous. The Courts regularly acquitted people who had been violent while delirious. Once the frenzy had passed it was obvious to the Court that the ability of the person to make rational judgements had been compromised by the fever or poisoning they had been laboring under.”
“But this is not the kind of psychosis that occurs spontaneously; delirium-psychosis starts when the drug is taken and clears when the drug is stopped. In its mildest form, others may just notice there is something odd or different about the person. If slightly more marked it can lead to a change of personality. In full-blown form, the person may be hallucinating and totally unaware of events and their surroundings. Almost all clinical trials of antidepressants have some patients who end up hallucinating, paranoid or deluded.

The important distinction which Dr Healy makes between psychosis and delirium-psychosis would not mean anything to most people. The average observer of a person in drug-induced delirium-psychosis would go only as far as assuming the person was “mentally ill”. The term used by the world at large for such states is “psychosis” as if that one term accurately describes all conditions relating to serious deviations from common perception.
A Yale study in 2001 found that 8.1% of 533 patients treated with fluoxetine (Prozac), fluvoxamine (Luvox), paroxetine (Paxil/Seroxat) or sertraline (Zoloft) experienced mania and/or psychosis.3 These effects probably reflect delirium rather than psychosis or mania and also reflect how prescribed coding can contribute to our lack of understanding of what is really going on, by using words like “mania” and “psychosis”.
Psychosis that is not caused by the ingestion of alcohol or drugs very rarely involves delirium. The afflicted person might hold strange beliefs and experience hallucinations but they are otherwise calm, and on most topics they can be quite rational. Because they are lucid and aware, people in “ordinary” psychosis who commit violent crimes cause courts and jurors great problems when it comes to deciding on matters of guilt and responsibility (This issue will be explored further in a future “Lessons” post). Consequently, violence to others is uncommon in patients who have not taken psychoactive medication. The only time such people are at risk of being violent are the very rare occasions when they are slipping into delusions or coming out of them.
A person in the throes of delusional thinking, who may also be experiencing akathisia, reduced inhibitions and ability to care, and who may be paranoid and angry for no logical reason, is a danger to others. While it is true that some people may experience such a state without medication, in recent decades, the vast majority of such cases are drug-induced, mostly by psychoactive drugs (legal or illegal), alone or in combination. Stopping the drugs suddenly can cause serious problems and often withdrawal is overlooked as a potential trigger to violence and suicide.
1 Apathy and Indifference in Patients on Fluvoxamine and Fluoxetine, Journal of Clinical Psychopharmacology, Vol 10, No 5, Oct 1990, Rudolph Hoen-Saric, MD, J Lipsey. MD and Daniel McLeod, PhD
2 Emotional side-effects of selective serotonin reuptake inhibitors: qualitative study, Price, Cole and Goodwin, The British Journal of Psychiatry (2009) 195, 211–217. doi: 10.1192/bjp.bp.108.051110
3 Antidepressant-Associated Mania and Psychosis Resulting in Psychiatric Admissions, Journal of Clinical Psychiatry, 2001; 62:30-33, by Adrian Preda M.D., Rebecca MacLean M.D., Carolyn Mazure, PhD and Malcolm Bowers M.D.