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.

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.

It is difficult to gain an accurate picture of incidence and prevalence of self-harm. This is due in a part to a lack of sufficient numbers of dedicated research centres to provide a continuous monitoring system. However, even with sufficient resources, statistical estimates are crude since most incidences of self-harm are undisclosed to the medical profession as acts of self-harm are frequently carried out in secret, and wounds may be superficial and easily treated by the individual. Recorded figures can be based on three sources: psychiatric samples, hospital admissions and general population surveys.

The World Health Organization estimates that, as of 2010, 880,000 deaths occur as a result of self-harm. About 10% of admissions to medical wards in the UK are as a result of self-harm, the majority of which are drug overdoses. However, studies based only on hospital admissions may hide the larger group of self-harmers who do not need or seek hospital treatment for their injuries, instead treating themselves. Many adolescents who present to general hospitals with deliberate self-harm report previous episodes for which they did not receive medical attention. In the United States up to 4% of adults self-harm with approximately 1% of the population engaging in chronic or severe self-harm.

Current research suggests that the rates of self-harm are much higher among young people with the average age of onset between 14 and 24. The earliest reported incidents of self-harm are in children between 5 and 7 years old. In the UK in 2008 rates of self-harm in young people could be as high as 33%. In addition there appears to be an increased risk of self-harm in college students than among the general population. In a study of undergraduate students in the US, 9.8% of the students surveyed indicated that they had purposefully cut or burned themselves on at least one occasion in the past. When the definition of self-harm was expanded to include head-banging, scratching oneself, and hitting oneself along with cutting and burning, 32% of the sample said they had done this. In Ireland, a study found that instances of hospital-treated self-harm were much higher in city and urban districts, than in rural settings. The CASE (Child & Adolescent Self-harm in Europe) study suggests that the life-time risk of self-injury is ~1:7 for women and ~1:25 for men.

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.

Some scholars believe that codependency is not a negative trait, and does not need to be treated, as it is more likely a healthy personality trait taken to excess. Codependency in nonclinical populations has some links with favourable characteristics of family functioning.

Stan Katz states that codependence is over-diagnosed, and that many people who could be helped with shorter-term treatments instead become dependent on long-term self-help programs. The language of, symptoms of, and treatment for codependence derive from the medical model suggesting a disease process underlies the behavior. However, there is no evidence that codependence is caused by a disease process.

In their book, “Attached.”, Dr. Amir Levine and Rachel S. F. Heller, address what they call the “codependency myth” by asserting that attachment theory is a more scientific and helpful model for understanding and dealing with attachment in adults.

In the dysfunctional family the child learns to become attuned to the parent's needs and feelings instead of the other way around. Parenting is a role that requires a certain amount of self-sacrifice and giving a child's needs a high priority. A parent can, nevertheless, be codependent towards their own children if the caretaking or parental sacrifice reaches unhealthy or destructive levels. Generally, a parent who takes care of their own needs (emotional and physical) in a healthy way will be a better caretaker, whereas a codependent parent may be less effective, or may even do harm to a child. Codependent relationships often manifest through enabling behaviors, especially between parents and their children. Another way to look at it is that the needs of an infant are necessary but temporary, whereas the needs of the codependent are constant. Children of codependent parents who ignore or negate their own feelings may become codependent.

The prevalence of scrupulosity is speculative. Available data do not permit reliable estimates, and available analyses mostly disregard associations with age or with gender, and have not reliably addressed associations with geography or ethnicity. Available data suggest that the prevalence of obsessive–compulsive disorder does not differ by culture, except where prevalence rates differ for all psychiatric disorders. No association between OCD and depth of religious beliefs has been demonstrated, although data are scarce. There are large regional differences in the percentage of OCD patients who have religious obsessions or compulsions, ranging from 0–7% in countries like the U.K. and Singapore, to 40–60% in traditional Muslim and orthodox Jewish populations.

A 2007 study found that 78% of a clinical sample of OCD patients had intrusive images. Most people who suffer from intrusive thoughts have not identified themselves as having OCD, because they may not have what they believe to be classic symptoms of OCD, such as handwashing. Yet, epidemiological studies suggest that intrusive thoughts are the most common kind of OCD worldwide; if people in the United States with intrusive thoughts gathered, they would form the fourth-largest city in the US, following New York City, Los Angeles, and Chicago.

The prevalence of OCD in every culture studied is at least 2% of the population, and the majority of those have obsessions, or bad thoughts, only; this results in a conservative estimate of more than 2 million sufferers in the United States alone (as of 2000). One author estimates that one in 50 adults have OCD and about 10–20% of these have sexual obsessions. A recent study found that 25% of 293 patients with a primary diagnosis of OCD had a history of sexual obsessions.

Marquis states how "Adolescent alcohol

use is not an acceptable rite of passage but a serious threat to adolescent

development and health, as the statistics related to adolescent impairment,

injury, and death attest." Research shows how an adolescent

makes the decision to consume alcohol because they are influenced by various

factors. "These factors include normal maturational changes that all

adolescents experience; genetic, psychological and social factors specific to

each adolescent and the various social and cultural environments that surround

adolescent, including their families, schools and communities". It is also

shown that early onset of alcohol intake can lead to high levels of alcohol use

in adulthood.

Alcoholism throughout adolescents is increasing yearly for a number of different reasons. These reasons include:

- Availability of alcohol

- Peer pressure

- Role model

- Television

- Anxiety or stress

The effects of psychedelics vary widely from one individual to the next, and from one experience to the next. Sometimes individuals under the influence of such drugs do not understand that they have taken a drug and believe that they will never return to their ordinary, sober perception. In cases where the individual cannot be kept safe, hospitalization may be useful, though the value of this practice for individuals not mentally ill is disputed by proponents of the investigative or recreational use of psychoactive compounds. Psychosis is exacerbated in individuals already suffering from this condition.

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.

In Europe, the rate of problem gambling is typically 0.5 to 3 percent. The "British Gambling Prevalence Survey 2007", conducted by the United Kingdom Gambling Commission, found approximately 0.6 percent of the adult population had problem gambling issues—the same percentage as in 1999. The highest prevalence of problem gambling was found among those who participated in spread betting (14.7%), fixed odds betting terminals (11.2%) and betting exchanges (9.8%). In Norway, a December 2007 study showed the amount of present problem gamblers was 0.7 percent.

Generally, a person experiencing a psychedelic crisis can be helped either to resolve the impasse, to bypass it, or, failing that, to terminate the experience. A person's thoughts before taking or while under the influence of the psychedelic, often greatly influence the trip.

Medical treatment consists of supportive therapy and minimization of external stimuli. In some cases, sedation is used when necessary to control self-destructive behavior, or when hyperthermia occurs. Diazepam is the most frequently used sedative for such treatment, but other benzodiazepines such as lorazepam are also effective. Such sedatives will only decrease fear and anxiety, but will not subdue hallucinations. In severe cases, antipsychotics such as haloperidol can reduce or stop hallucinations. Haloperidol is effective against drug-induced psychosis caused by LSD and other tryptamines, amphetamines, ketamine and phencyclidine.

Factors that can cause reluctance to attend school can be divided into four categories. These categories have been developed based on studies in the United States under the leadership of Professor Christopher Kearney. Some students may be affected by several factors at once.

- The child might want to be free.

- The child possibly wants to avoid school-related issues and situations that cause them to experience unpleasant feelings, such as anxiety, depression, or psychosomatic symptoms. The reluctance to attend school is one symptom that can indicate the presence of a larger issue, such as anxiety disorder, depression, learning disability, sleep disorder, separation anxiety or panic disorder.

- The child may want to avoid tests, presentations, group work, specific lessons, or interaction with other children. The child should be assessed for learning disabilities if academic performance is average or low.

- The child may want attention from significant people outside of school, such as parents or older acquaintances.

- The child possibly wants to do something more enjoyable outside of school, like practice hobbies, play computer games, watch movies, play with friends such as riding bikes, etc., or learn autodidactictally.

Other factors can be:

- Anxiety about academic achievement and being tested can arise on the basis of inflated claims by teachers and/or parents, but also unrealistic ambitions of the upset child themselves.

- School refusal may arise as a response to bullying or peer rejection.

- Shyness or a social phobia can contribute to school refusal.

- The child might worry about parents or siblings, for instance, a parent with substance abuse, or a parent who physically abuses other family members.

- Some students may refuse to go to school due to anxiety or fears of emergency drills, such as fire, lockdown, and tornado drills.

In the United States, the percentage of pathological gamblers was 0.6 percent, and the percentage of problem gamblers was 2.3 percent in 2008. Studies commissioned by the National Gambling Impact Study Commission Act has shown the prevalence rate ranges from 0.1 percent to 0.6 percent. Nevada has the highest percentage of pathological gambling; a 2002 report estimated 2.2 to 3.6 percent of Nevada residents over the age of 18 could be called problem gamblers. Also, 2.7 to 4.3 percent could be called probable pathological gamblers.

According to a 1997 meta-analysis by Harvard Medical School's division on addictions, 1.1 percent of the adult population of the United States and Canada could be called pathological gamblers. A 1996 study estimated 1.2 to 1.9 percent of adults in Canada were pathological. In Ontario, a 2006 report showed 2.6 percent of residents experienced "moderate gambling problems" and 0.8 percent had "severe gambling problems". In Quebec, an estimated 0.8 percent of the adult population were pathological gamblers in 2002. Although most who gamble do so without harm, approximately 6 million American adults are addicted to gambling.

Signs of a gambling problem include:

- Using income or savings to gamble while letting bills go unpaid

- Repeated, unsuccessful attempts to stop gambling

- Chasing losses

- Losing sleep over thoughts of gambling

- Arguing with friends or family about gambling behavior

- Feeling depressed or suicidal because of gambling losses

The problems of self-neglect and elder and child abuse are also health problems associated with animal hoarding. Self-neglect can be defined as "the inability to provide for oneself the goods or services to meet basic needs", and has been shown to be an "independent risk factor for death". While self-neglect is a condition generally associated with the elderly, animal hoarders of any age can and do suffer from it. This is demonstrated by the fact that hoarders' lifestyles often match the degenerate sanitary conditions that surround them. Child and elder abuse arise when dependents are living with the hoarder. According to one study, dependents lived with hoarders in over half of the cases. As with his or her animals, the hoarder often fails to provide adequate care for dependents both young and old, who suffer from a lack of basic necessities as well as the health problems caused by unsanitary conditions. In one case, two children of a couple hoarding 58 cats and other animals were forced to repeat kindergarten and first grade because of excessive absence due to respiratory infections. Self-neglect and neglect of dependents make up a major human health concern of animal hoarding.

Approximately 1 to 5% of school-aged children have school refusal, though it is most common in 5- and 6-year olds and in 10- and 11-year olds, it occurs more frequently during major changes in a child’s life, such as entrance to kindergarten, changing from elementary to middle school, or changing from middle to high school. The problem may start following vacations, school holidays, summer vacation, or brief illness, after the child has been home for some time, and usually ends prior to vacations, school holidays, or summer vacation, before the child will be out of school for some time. School refusal can also occur after a stressful event, such as moving to a new house, or the death of a pet or relative.

The rate is similar within both genders, and although it is significantly more prevalent in some urban areas, there are no known socioeconomic differences.

A legal minimum age for the buying or consuming of alcohol is in place in many of the world's countries, typically with the intent to protect the young from alcohol-related harm. This age varies between countries; for example, the minimum legal drinking age for Australia is 18, whereas the MLDA in the United States is 21.

Another human health issue caused by animal hoarding is the risk of zoonotic diseases. Defined as "human diseases acquired from or transmitted to any other vertebrate animal", zoonotic diseases can often be lethal and in all cases constitute a serious public health concern. Examples of well-known zoonotic diseases include bubonic plague, influenza, and rabies. Common domesticated animals constitute a large portion of animals carrying zoonoses, and as a result, humans involved in animal hoarding situations are at particular risk of contracting disease. Zoonoses that may arise in hoarding situations—through vectors such as dog, cat, or rat bites—include rabies, salmonellosis, catscratch fever, hookworm, and ringworm. One zoonosis of special concern is toxoplasmosis, which can be transmitted to humans through cat feces or badly-prepared meat, and is known to cause severe birth defects or stillbirth in the case of infected pregnant women. The risk of zoonotic diseases is amplified by the possibility of community epidemics.

Individual differences in women's estrogen cycles may be related to the expression of BPD symptoms in female patients. A 2003 study found that women's BPD symptoms were predicted by changes in estrogen levels throughout their menstrual cycles, an effect that remained significant when the results were controlled for a general increase in negative affect.

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.

Emotional dysregulation (ED) is a term used in the mental health community to refer to an emotional response that is poorly modulated, and does not fall within the conventionally accepted range of emotive response.

Possible manifestations of emotional dysregulation include angry outbursts or behavior outbursts such as destroying or throwing objects, aggression towards self or others, and threats to kill oneself. These variations usually occur in seconds to minutes or hours. Emotional dysregulation can lead to behavioral problems and can interfere with a person's social interactions and relationships at home, in school, or at place of employment.

Emotional dysregulation can be associated with an experience of early psychological trauma, brain injury, or chronic maltreatment (such as child abuse, child neglect, or institutional neglect/abuse), and associated disorders such as reactive attachment disorder. Emotional dysregulation may present in people with psychiatric disorders such as attention deficit hyperactivity disorder, bipolar disorder, borderline personality disorder, narcissistic personality disorder, and complex post-traumatic stress disorder. ED is also found among those with autism spectrum disorders. In such cases as borderline personality disorder, hypersensitivity to emotional stimuli causes a slower return to a normal emotional state. This is manifested biologically by deficits in the frontal cortices of the brain.

As is the case with other mental disorders, the causes of BPD are complex and not fully agreed upon. Evidence suggests that BPD and post-traumatic stress disorder (PTSD) may be related in some way. Most researchers agree that a history of childhood trauma can be a contributing factor, but less attention has historically been paid to investigating the causal roles played by congenital brain abnormalities, genetics, neurobiological factors, and environmental factors other than trauma.

Social factors include how people interact in their early development with their family, friends, and other children. Psychological factors include the individual's personality and temperament, shaped by their environment and learned coping skills that deal with stress. These different factors together suggest that there are multiple factors that may contribute to the disorder.

Treatment is similar to that for other forms of obsessive–compulsive disorder. Exposure and response prevention (ERP), a form of behavior therapy, is widely used for OCD in general and may be promising for scrupulosity in particular. ERP is based on the idea that deliberate repeated exposure to obsessional stimuli lessens anxiety, and that avoiding rituals lowers the urge to behave compulsively. For example, with ERP a person obsessed by blasphemous thoughts while reading the Bible would practice reading the Bible. However, ERP is considerably harder to implement than with other disorders, because scrupulosity often involves spiritual issues that are not specific situations and objects. For example, ERP is not appropriate for a man obsessed by feelings that God has rejected and is punishing him. Cognitive therapy may be appropriate when ERP is not feasible. Other therapy strategies include noting contradictions between the compulsive behaviors and moral or religious teachings, and informing individuals that for centuries religious figures have suggested strategies similar to ERP. Religious counseling may be an additional way to readjust beliefs associated with the disorder, though it may also stimulate greater anxiety.

Little evidence is available on the use of medications to treat scrupulosity. Although serotonergic medications are often used to treat OCD, studies of pharmacologic treatment of scrupulosity in particular have produced so few results that even tentative recommendations cannot be made.

Treatment of scrupulosity in children has not been investigated to the extent it has been studied in adults, and one of the factors that makes the treatment difficult is the fine line the therapist must walk between engaging and offending the client.

Unwanted thoughts by mothers about harming infants are common in postpartum depression. A 1999 study of 65 women with postpartum major depression by Katherine Wisner "et al." found the most frequent aggressive thought for women with postpartum depression was causing harm to their newborn infants. A study of 85 new parents found that 89% experienced intrusive images, for example, of the baby suffocating, having an accident, being harmed, or being kidnapped.

Some women may develop symptoms of OCD during pregnancy or the postpartum period. Postpartum OCD occurs mainly in women who may already have OCD, perhaps in a mild or undiagnosed form. Postpartum depression and OCD may be comorbid (often occurring together). And though physicians may focus more on the depressive symptoms, one study found that obsessive thoughts did accompany postpartum depression in 57% of new mothers.

Wisner found common obsessions about harming babies in mothers experiencing postpartum depression include images of the baby lying dead in a casket or being eaten by sharks; stabbing the baby; throwing the baby down the stairs; or drowning or burning the baby (as by submerging it in the bathtub in the former case or throwing it in the fire or putting it in the microwave in the latter). Baer estimates that up to 200,000 new mothers with postpartum depression each year may develop these obsessional thoughts about their babies; and because they may be reluctant to share these thoughts with a physician or family member, or suffer in silence and fear they are "crazy", their depression can worsen.

Intrusive fears of harming immediate children can last longer than the postpartum period. A study of 100 clinically depressed women found that 41% had obsessive fears that they might harm their child, and some were afraid to care for their children. Among non-depressed mothers, the study found 7% had thoughts of harming their child—a rate that yields an additional 280,000 non-depressed mothers in the United States with intrusive thoughts about harming their children.