Substance abuse is the second most common risk factor for suicide after major depression and bipolar disorder. Both chronic substance misuse as well as acute intoxication are associated. When combined with personal grief, such as bereavement, the risk is further increased. Substance misuse is also associated with mental health disorders.

Most people are under the influence of sedative-hypnotic drugs (such as alcohol or benzodiazepines) when they die by suicide with alcoholism present in between 15% and 61% of cases. Use of prescribed benzodiazepines is asscociated with an increased rate of attempted and completed suicide. The prosuicidal effects of benzodiazepines are suspected to be due to a psychiatric disturbance caused by side effects or withdrawal symptoms. Countries that have higher rates of alcohol use and a greater density of bars generally also have higher rates of suicide. About 2.2–3.4% of those who have been treated for alcoholism at some point in their life die by suicide. Alcoholics who attempt suicide are usually male, older, and have tried to take their own lives in the past. Between 3 and 35% of deaths among those who use heroin are due to suicide (approximately fourteenfold greater than those who do not use). In adolescents who misuse alcohol, neurological and psychological dysfunctions may contribute to the increased risk of suicide.

The misuse of cocaine and methamphetamine has a high correlation with suicide. In those who use cocaine the risk is greatest during the withdrawal phase. Those who used inhalants are also at significant risk with around 20% attempting suicide at some point and more than 65% considering it. Smoking cigarettes is associated with risk of suicide. There is little evidence as to why this association exists; however it has been hypothesized that those who are predisposed to smoking are also predisposed to suicide, that smoking causes health problems which subsequently make people want to end their life, and that smoking affects brain chemistry causing a propensity for suicide. Cannabis however does not appear to independently increase the risk.

Problem gambling is associated with increased suicidal ideation and attempts compared to the general population. Between 12 and 24% pathological gamblers attempt suicide. The rate of suicide among their spouses is three times greater than that of the general population. Other factors that increase the risk in problem gamblers include mental illness, alcohol and drug misuse.

Substance misuse, dependence and withdrawal are associated with self-harm. Benzodiazepine dependence as well as benzodiazepine withdrawal is associated with self-harming behaviour in young people. Alcohol is a major risk factor for self-harm. A study which analysed self-harm presentations to emergency rooms in Northern Ireland found that alcohol was a major contributing factor and involved in 63.8% of self-harm presentations. A recent study in the relation between cannabis use and deliberate self-harm (DSH) in Norway and England found that, in general, cannabis use may not be a specific risk factor for DSH in young adolescents.

In general, the latest aggregated research has found no difference in the prevalence of self-harm between men and women. This is in contrast to past research which indicated that up to four times as many females as males have direct experience of self-harm. However, caution is needed in seeing self-harm as a greater problem for females, since males may engage in different forms of self-harm (e.g., hitting themselves) which could be easier to hide or explained as the result of different circumstances. Hence, there remain widely opposing views as to whether the gender paradox is a real phenomenon, or merely the artifact of bias in data collection.

The WHO/EURO Multicentre Study of Suicide, established in 1989, demonstrated that, for each age group, the female rate of self-harm exceeded that of the males, with the highest rate among females in the 13–24 age group and the highest rate among males in the 12–34 age group. However, this discrepancy has been known to vary significantly depending upon population and methodological criteria, consistent with wide-ranging uncertainties in gathering and interpreting data regarding rates of self-harm in general. Such problems have sometimes been the focus of criticism in the context of broader psychosocial interpretation. For example, feminist author Barbara Brickman has speculated that reported gender differences in rates of self-harm are due to deliberate socially biased methodological and sampling errors, directly blaming medical discourse for pathologising the female.

This gender discrepancy is often distorted in specific populations where rates of self-harm are inordinately high, which may have implications on the significance and interpretation of psychosocial factors other than gender. A study in 2003 found an extremely high prevalence of self-harm among 428 homeless and runaway youths (aged 16–19) with 72% of males and 66% of females reporting a history of self-harm. However, in 2008, a study of young people and self-harm saw the gender gap widen in the opposite direction, with 32% of young females, and 22% of young males admitting to self-harm. Studies also indicate that males who self-harm may also be at a greater risk of completing suicide.

There does not appear to be a difference in motivation for self-harm in adolescent males and females. For example, for both genders there is an incremental increase in deliberate self-harm associated with an increase in consumption of cigarettes, drugs and alcohol. Triggering factors such as low self-esteem and having friends and family members who self-harm are also common between both males and females. One limited study found that, among those young individuals who do self-harm, both genders are just as equally likely to use the method of skin-cutting. However, females who self-cut are more likely than males to explain their self-harm episode by saying that they had wanted to punish themselves. In New Zealand, more females are hospitalised for intentional self-harm than males. Females more commonly choose methods such as self-poisoning that generally are not fatal, but still serious enough to require hospitalisation.

The combination of self-starvation and alcohol abuse can lead to an array of physical and psychological consequences. For example, drinking in a state of malnutrition can predispose individuals to a higher rate of blackouts, alcohol poisoning, alcohol-related injury, violence, or illness. Drinking on an empty stomach allows ethanol to reach the blood system at a swifter pace and raises one's blood alcohol content with an often dangerous speed. This can render the drinker more vulnerable to alcohol-related brain damage. In addition, alcohol abuse can have a detrimental impact on hydration and the body's retention of minerals and nutrients, further exacerbating the consequences of malnutrition and denigrating an individual's cognitive faculties. This can ultimately have a negative impact on academic performance.

These harmful consequences can be more easily induced in women, as women are oftentimes less capable of metabolizing alcohol than men. On CBS News, Carrie Wilkins, PhD, of the Center for Motivation and Change (a private practice group based in New York City) describes how women are more vulnerable to particular toxic side effects of alcohol consumption.

Drunkorexia can lead to short term and long term cognitive problems including difficulty concentrating and difficulty making decisions. It also increases the risk of developing more serious eating disorders or alcohol abuse problems. As binge drinking is involved there is a greater risk for violence, risky sexual behavior, alcohol poisoning, substance abuse and chronic disease later in life.

Drunkorexia is not a medically diagnosed disorder therefore there is no specific treatment. However, as drunkorexia is a combination of two different disorders, binge drinking and eating disorders such as anorexia and bulimia the treatment will need to address both.

While the causes of PPD are not understood, a number of factors have been suggested to increase the risk:

- Prenatal depression or anxiety

- A personal or family history of depression

- Moderate to severe premenstrual symptoms

- Maternity blues

- Birth-related psychological trauma

- Birth-related physical trauma

- Previous stillbirth or miscarriage

- Formula-feeding rather than breast-feeding

- Cigarette smoking

- Low self-esteem

- Childcare or life stress

- Low social support

- Poor marital relationship or single marital status

- Low socioeconomic status

- Infant temperament problems/colic

- Unplanned/unwanted pregnancy

- Elevated prolactin levels

- Oxytocin depletion

Of these risk factors, formula-feeding, a history of depression, and cigarette smoking have been shown to have additive effects.

These above factors are known to correlate with PPD. This correlation does not mean these factors are causal. Rather, they might both be caused by some third factor. Contrastingly, some factors almost certainly attribute to the cause of postpartum depression, such as lack of social support.

Not surprisingly, women with fewer resources indicate a higher level of postpartum depression and stress than those women with more resources, such as financial. Rates of PPD have been shown to decrease as income increases. Women with fewer resources may be more likely to have an unintended or unwanted pregnancy, increasing risk of PPD. Women with fewer resources may also include single mothers of low income. Single mothers of low income may have more limited access to resources while transitioning into motherhood.

Studies have also shown a correlation between a mother's race and postpartum depression. African American mothers have been shown to have the highest risk of PPD at 25%, while Asian mothers had the lowest at 11.5%, after controlling for social factors such as age, income, education, marital status, and baby's health. The PPD rates for First Nations, Caucasian and Hispanic women fell in between.

Sexual orientation has also been studied as a risk factor for PPD. In a 2007 study conducted by Ross and colleagues, lesbian and bisexual mothers were tested for PPD and then compared with a heterosexual sample group. It was found that lesbian and bisexual biological mothers had significantly higher Edinburgh Postnatal Depression Scale scores than did the heterosexual women in the sample. These higher rates of PPD in lesbian/bisexual mothers may reflect less social support, particularly from their families of origin and additional stress due to homophobic discrimination in society.

A correlation between postpartum thyroiditis and postpartum depression has been proposed but remains controversial. There may also be a link between postpartum depression and anti-thyroid antibodies.

Postpartum depression is found across the globe, with rates varying from 11% to 42%. Around 3% to 6% of women will experience depression during pregnancy or shortly after giving birth. About 1 in 750 mothers will have postpartum depression with psychosis and their risk is higher if they have had postpartum episodes in the past.

MSbP is rare. A recent systematic study in Italy found that in a series of over 700 patients admitted to a pediatric ward, 4 cases met the diagnostic criteria for MSbP (0.53%). In this study, stringent diagnostic criteria were used, which required at least one test outcome or event that could not possibly have occurred without deliberate intervention by the MSbP person.

One study showed that in 93 percent of MSbP cases, the abuser is the mother or another female guardian or caregiver. This may be attributed to the prevalent socialization pattern that places females in the primary care-taking role. Of course, it could also be a gender trait rooted in genetics, as it is easy to see how females who seek attention as victims could gain an evolutionary advantage, while men seeking the same would be unfavoured for physical protection and mating. A psychodynamic model of this kind of maternal abuse exists.

MSbP may be more prevalent in the parents of those with a learning difficulty or mental incapacity, and as such the apparent patient could, in fact, be an adult.

Fathers and other male caregivers have been the perpetrators in only 7% of the cases studied. When they are not actively involved in the abuse, the fathers or male guardians of MSbP victims are often described as being distant, emotionally disengaged, and powerless. These men play a passive role in MSbP by being frequently absent from the home and rarely visiting the hospitalized child. Usually, they vehemently deny the possibility of abuse, even in the face of overwhelming evidence or their child's pleas for help.

Overall, male and female children are equally likely to be the victim of MSbP. In the few cases where the father is the perpetrator, however, the victim is three times more likely to be male.

Male anabolic-androgenic steroid abusers often have a troubled social background.

The cause of sleepwalking is not known. A number of, as yet unproven, hypotheses are suggested for why it might occur. These include a delay in the maturity of the central nervous system, increased slow wave sleep, sleep deprivation, fever, and excessive tiredness.

There may be a genetic component to sleepwalking. One study found that sleepwalking occurred in 45% of children who have one parent who sleepwalked, and in 60% of children if both parents sleepwalked. Thus, heritable factors may predispose an individual to sleepwalking, but expression of the behavior may also be influenced by environmental factors. Genetic studies using common fruit flies as experimental models reveal a link between night sleep and brain development mediated by evolutionary conserved transcription factors such as AP-2

Sleepwalking may be inherited as an autosomal dominant disorder with reduced penetrance. Genome-wide multipoint parametric linkage analysis for sleepwalking revealed a maximum logarithm of the odds score of 3.14 at chromosome 20q12-q13.12 between 55.6 and 61.4 cM.

Medications, primarily in four classes—benzodiazepine receptor agonists and other GABA modulators, antidepressants and other serotonergic agents, antipsychotics, and β-blockers— have been associated with sleepwalking. The best evidence of medications causing sleepwalking is for Zolpidem and sodium oxybate—all other reports are based on associations noted in case reports.

A number of conditions, such as Parkinson's Disease, are thought to trigger sleepwalking in people without a previous history of sleepwalking.

25% of male weightlifters reported memories of childhood physical or sexual abuse in an interview. Anabolic steroids are sometimes used by people with muscle dysmorphia (a very specific type of body dysmorphic disorder (BDD)) as a defense mechanism. Interestingly, yohimbine, while considered something of a flop as a supplement for failing to increase testosterone levels as had at first been suspected, has at higher doses been discovered to be useful in facilitating recall of traumatic memories during post traumatic stress disorder (PTSD) treatment.

Traumatic grief or complicated mourning are conditions where both trauma and grief coincide. There are conceptual links between trauma and bereavement since loss of a loved one is inherently traumatic. If a traumatic event was life-threatening, but did not result in death, then it is more likely that the survivor will experience post-traumatic stress symptoms. If a person dies, and the survivor was close to the person who died, then it is more likely that symptoms of grief will also develop. When the death is of a loved one, and was sudden or violent, then both symptoms often coincide. This is likely in children exposed to community violence.

For C-PTSD to manifest, the violence would occur under conditions of captivity, loss of control and disempowerment, coinciding with the death of a friend or loved one in life-threatening circumstances. This again is most likely for children and stepchildren who experience prolonged domestic or chronic community violence that ultimately results in the death of friends and loved ones. The phenomenon of the increased risk of violence and death of stepchildren is referred to as the Cinderella effect.

Often, apathy is felt after witnessing horrific acts, such as the killing or maiming of people during a war, e.g. posttraumatic stress disorder. It is also known to be a distinct psychiatric syndrome that is associated with many conditions, some of which are: CADASIL syndrome, depression, Alzheimer's disease, Chagas disease, Creutzfeldt–Jakob disease, dementia (and dementias such as Alzheimer's disease, vascular dementia, and frontotemporal dementia), Korsakoff's syndrome, excessive vitamin D, hypothyroidism, hyperthyroidism, general fatigue, Huntington's disease, Pick's disease, progressive supranuclear palsy (PSP), brain damage, schizophrenia, schizoid personality disorder, bipolar disorder, autism, ADHD, Asperger's syndrome, and others. Some medications and the heavy use of drugs such as opiates or GABA-ergic drugs may bring apathy as a side effect.

Egomania is also known as an obsessive preoccupation with one's self and applies to someone who follows their own ungoverned impulses and is possessed by delusions of personal greatness and feels a lack of appreciation. Someone suffering from this extreme egocentric focus is an egomaniac. The condition is psychologically abnormal.

The term "egomania" is often used by laypersons in a pejorative fashion to describe an individual who is intolerably self-centred. The clinical condition that most resembles the popular conception of egomania is narcissistic personality disorder.

Vicarious trauma affects workers being 'witnesses' to their clients' trauma. It is more likely to occur in situations where trauma related work is the norm rather than the exception. Listening with empathy to the clients generates feeling, and 'seeing oneself' in clients' trauma may compound the risk for developing trauma symptoms. May also result if we are witness to situations that happen in the course of our work (e.g. violence in the workplace, reviewing violent video tapes, etc.). Risk increases with exposure and with the absence of seeking protective factors and pre-preparation of preventive strategies.

Among the most common type of wounds are a rifle shot to the hand, arm, leg, or foot.

Wounds can also occur by deliberate neglect of health, e.g. by failing to treat a minor wound that will become infected, or "forgetting" foot care in damp conditions that lead to fungal infections.

Sleepwalking, also known as somnambulism or noctambulism, is a phenomenon of combined sleep and wakefulness. It is classified as a sleep disorder belonging to the parasomnia family. It occurs during slow wave sleep stage, in a state of low consciousness, with performance of activities that are usually performed during a state of full consciousness. These activities can be as benign as sitting up in bed, walking to a bathroom, and cleaning, or as hazardous as cooking, driving, violent gestures, grabbing at hallucinated objects, or even homicide.

Although sleepwalking cases generally consist of simple, repeated behaviours, there are occasionally reports of people performing complex behaviours while asleep, although their legitimacy is often disputed. Sleepwalkers often have little or no memory of the incident, as their consciousness has altered into a state in which it is harder to recall memories. Although their eyes are open, their expression is dim and glazed over. This may last from 30 seconds to 30 minutes.

Sleepwalking occurs during slow-wave sleep (N3) of non-rapid eye movement sleep (NREM sleep) cycles. It typically occurs within the first third of the night when slow-wave sleep is most prominent. Usually, it will occur once in a night, if at all.

A self-inflicted wound (SIW), is the act of harming oneself where there are no underlying psychological problems related to the self-injury, but where the injurer wanted to take advantage of being injured.

Video game addiction (VGA) is a hypothetical behavioral addiction characterized by excessive or compulsive use of computer games or video games, which interferes with a person's everyday life. Video game addiction may present itself as compulsive gaming, social isolation, mood swings, diminished imagination, and hyper-focus on in-game achievements, to the exclusion of other events in life.

In May 2013, the American Psychiatric Association (APA) proposed criteria for video game addiction in the 5th edition of the "Diagnostic and Statistical Manual of Mental Disorders", concluding that there was insufficient evidence to include it as an official mental disorder. However, proposed criteria for "Internet Gaming Disorder" were included in a section called "Conditions for Further Study".

While Internet gaming disorder is proposed as a disorder, it is still discussed how much this disorder is caused by the gaming activity itself, or whether it is to some extent an effect of other disorders. Contradictions in research examining video game addictiveness may reflect more general inconsistencies in video game research. For example, while some research has linked violent video games with increased aggressive behavior other research has failed to find evidence for such links.

Depersonalization has been described by some as a desirable state, particularly by those that have experienced it under the influence of mood-altering recreational drugs. It is an effect of dissociatives and psychedelics, as well as a possible side effect of caffeine, alcohol, amphetamine, and cannabis. It is a classic withdrawal symptom from many drugs.

Benzodiazepine dependence, which can occur with long-term use of benzodiazepines, can induce chronic depersonalization symptomatology and perceptual disturbances in some people, even in those who are taking a stable daily dosage, and it can also become a protracted feature of the benzodiazepine withdrawal syndrome.

Lieutenant Colonel Dave Grossman, in his book "", suggests that military training artificially creates depersonalization in soldiers, suppressing empathy and making it easier for them to kill other human beings.

Graham Reed (1974) noted that depersonalization occurs in relation to the experience of falling in love.

C-PTSD may share some symptoms with both PTSD and borderline personality disorder.

It may help to understand the intersection of attachment theory with C-PTSD and BPD if one reads the following opinion of Bessel A. van der Kolk together with an understanding drawn from a description of BPD:

Uncontrollable disruptions or distortions of attachment bonds precede the development of post-traumatic stress syndromes. People seek increased attachment in the face of danger. Adults, as well as children, may develop strong emotional ties with people who intermittently harass, beat, and, threaten them. The persistence of these attachment bonds leads to confusion of pain and love. Trauma can be repeated on behavioural, emotional, physiologic, and neuroendocrinologic levels. Repetition on these different levels causes a large variety of individual and social suffering.

However, C-PTSD and BPD have been found by researchers to be completely distinctive disorders with incredibly different features – notably, C-PTSD is not a personality disorder – those who suffer do not fear abandonment, do not have unstable patterns of relations – rather they withdraw and they do not struggle with lack of empathy.

There are distinct and notably large differences between Borderline and C-PTSD and while there are some similarities – predominantly in terms of issues with attachment (though this plays out in completely different ways) and trouble regulating strong emotional effect (often feel pain vividly), the disorders are completely different in nature – especially considering that C-PTSD is always a response to trauma rather than a personality disorder. In addition, C-PTSD is not a personality disorder – rather it is often a case of survival reactions to trauma becoming a fundamental aspect of the personality, "in response to" living with a personality disordered individual.

"While the individuals in the BPD reported many of the symptoms of PTSD and CPTSD, the BPD class was clearly distinct in its endorsement of symptoms unique to BPD. The RR ratios presented in Table 5 revealed that the following symptoms were highly indicative of placement in the BPD rather than the CPTSD class: (1) frantic efforts to avoid real or imagined abandonment, (2) unstable and intense interpersonal relationships characterized by alternating between extremes of idealization and devaluation, (3) markedly and persistently unstable self-image or sense of self, and (4) impulsiveness. Given the gravity of suicidal and self-injurious behaviors, it is important to note that there were also marked differences in the presence of suicidal and self-injurious behaviors with approximately 50% of individuals in the BPD class reporting this symptom but much fewer and an equivalent number doing so in the CPSD and PTSD classes (14.3 and 16.7%, respectively). The only BPD symptom that individuals in the BPD class did not differ from the CPTSD class was chronic feelings of emptiness, suggesting that in this sample, this symptom is not specific to either BPD or CPTSD and does not discriminate between them."

"Overall, the findings indicate that there are several ways in which Complex PTSD and BPD differ, consistent with the proposed diagnostic formulation of CPTSD. BPD is characterized by fears of abandonment, unstable sense of self, unstable relationships with others, and impulsive and self-harming behaviors. In contrast, in CPTSD as in PTSD, there was little endorsement of items related to instability in self-representation or relationships. Self-concept is likely to be consistently negative and relational difficulties concern mostly avoidance of relationships and sense of alienation."

In addition 25% of those diagnosed with BPD have no known history of childhood neglect or abuse and individuals are six times as likely to develop BPD if they have a relative who was so diagnosed compared to those who do not. One conclusion is that there is a genetic predisposition to BPD unrelated to trauma. Researchers conducting a longitudinal investigation of identical twins found that "genetic factors play a major role in individual differences of borderline personality disorder features in Western society." A 2014 study published in European Journal of Psychotraumatology was able to compare and contrast C-PTSD, PTSD, Borderline Personality Disorder and found that it could distinguish between individual cases of each and when it was co-morbid, arguing for a case of separate diagnoses for each. BPD may be confused with C-PTSD by some without proper knowledge of the two conditions because those with BPD also tend to suffer from PTSD or to have some history of trauma.

In "Trauma and Recovery," Herman expresses the additional concern that patients who suffer from C-PTSD frequently risk being misunderstood as inherently 'dependent', 'masochistic', or 'self-defeating', comparing this attitude to the historical misdiagnosis of female hysteria. However, those who develop C-PTSD do so as a result of the intensity of the trauma bond – in which someone becomes tightly biolo-chemically bound to someone who abuses them (also known as Stockholm Syndrome – seen in cases of kidnapping in which a person falls in love with their captors) and the responses they learned to survive, navigate and deal with the abuse they suffered then become automatic responses, imbedded in their personality over the years of trauma – a normal reaction to an abnormal situation.

Depersonalization is also a direct symptom of Lyme disease as well as other tick-borne diseases. If depersonalization is suspected a blood-test is required in search of anti-bodies.

When an inferiority complex is in full effect, it may impact the performance of an individual as well as impact an individual's self-esteem. Unconscious psychological and emotional processes can disrupt students’ cognitive learning, and negatively “charged” feeling-toned memory associations can derail the learning process. Hutt found that math can become associated with a psychological inferiority complex, low motivation and self-efficacy, poor self-directed learning strategies, and feeling unsafe or anxious.

In the mental health treatment population, this characteristic is shown in patients with many disorders such as certain types of schizophrenia, mood disorders, and personality disorders. Moritz found that people suffering from paranoid schizophrenia used their delusions as a defense mechanism against low implicit self-esteem. Alfred Adler identified an inferiority complex as one of the contributing factors to problem child behaviors.

All psychological traumas originate from stress, a physiological response to an unpleasant stimulus. Long term stress increases the risk of poor mental health and mental disorders, which can be attributed to secretion of glucocorticoids for a long period of time. Such prolonged exposure causes many physiological dysfunctions such as the suppression of the immune system and increase in blood pressure. Not only does it affect the body physiologically, but a morphological change in the hippocampus also takes place. Studies showed that extreme stress early in life can disrupt normal development of hippocampus and impact its functions in adulthood. Studies surely show a correlation between the size of hippocampus and one's susceptibility to stress disorders. In times of war, psychological trauma has been known as shell shock or combat stress reaction. Psychological trauma may cause an acute stress reaction which may lead to posttraumatic stress disorder (PTSD). PTSD emerged as the label for this condition after the Vietnam War in which many veterans returned to their respective countries demoralized, and sometimes, addicted to psychoactive substances. The symptoms of PTSD must persist for at least a month for diagnosis. The main symptoms of PTSD consist of four main categories: Trauma (i.e. intense fear), reliving (i.e. flashbacks), avoidance behavior (i.e. emotional numbing), and hypervigilance (i.e. irritability). Research shows that about 60% of the US population reported as having experienced at least one traumatic symptom in their lives but only a small proportion actually develops PTSD. There is a correlation between the risk of PTSD and whether or not the act was inflicted deliberately by the offender. Psychological trauma is treated with therapy and, if indicated, psychotropic medications.

The term "continuous post traumatic stress disorder" (CTSD) was introduced into the trauma literature by Gill Straker (1987). It was originally used by South African clinicians to describe the effects of exposure to frequent, high levels of violence usually associated with civil conflict and political repression. The term is also applicable to the effects of exposure to contexts in which gang violence and crime are endemic as well as to the effects of ongoing exposure to life threats in high-risk occupations such as police, fire and emergency services.

As one of the processes of treatment, confrontation with their sources of trauma plays a crucial role. While critical incident debriefing people immediately after an event has not been shown to reduce incidence of PTSD, coming alongside people experiencing trauma in a supportive way has become standard practice.