Only a small proportion of those with co-occurring disorders actually receive treatment for both disorders. Therefore, it was argued that a new approach is needed to enable clinicians, researchers and managers to offer adequate assessment and evidence-based treatments to patients with dual pathology, who cannot be adequately and efficiently managed by cross-referral between psychiatric and addiction services as currently configured and resourced. In 2011, it was estimated that only 12.4% of American adults with co-occurring disorders were receiving both mental health and addictions treatment. Clients with co-occurring disorders face challenges accessing treatment, as they may be excluded from mental health services if they admit to a substance abuse problem, and vice versa.

There are multiple approaches to treating concurrent disorders. Partial treatment involves treating only the disorder that is considered primary. Sequential treatment involves treating the primary disorder first, and then treating the secondary disorder after the primary disorder has been stabilized. Parallel treatment involves the client receiving mental health services from one provider, and addictions services from another.

Integrated treatment involves a seamless blending of interventions into a single coherent treatment package developed with a consistent philosophy and approach among care providers. With this approach, both disorders are considered primary. Integrated treatment can improve accessibility, service individualization, engagement in treatment, treatment compliance, mental health symptoms, and overall outcomes. The Substance Abuse and Mental Health Services Administration in the United States describes integrated treatment as being in the best interests or clients, programs, funders, and systems. Green suggested that treatment should be integrated, and a collaborative process between the treatment team and the patient. Furthermore, recovery should to be viewed as a marathon rather than a sprint, and methods and outcome goals should be explicit.

Although many patients may reject medications as antithetical to substance-abuse recovery and side effects, they can be useful to reduce paranoia, anxiety, and craving. Medications that have proven effective include opioid replacement therapies, such as lifelong maintenance on methadone or buprenorphine, to minimize risk of relapse, fatality, and legal trouble amongst opioid addicts, as well as helping with cravings, baclofen for alcoholics, opioid addicts, cocaine addicts, and amphetamine addicts, to help eliminate drug cravings, and clozapine, the first atypical antipsychotic, which appears to reduce illicit drug use amongst stimulant addicts. Clozapine can cause respiratory arrest when combined with alcohol, benzodiazepines, or opioids, so it is not recommended to use in these groups.

The self-medication theory suggests that people with severe mental illnesses misuse substances in order to relieve a specific set of symptoms and counter the negative side-effects of antipsychotic medication.

Khantizan proposes that substances are not randomly chosen, but are specifically selected for their effects. For example, using stimulants such as nicotine or amphetamines can be used to combat the sedation that can be caused by higher doses of certain types of (usually typical) antipsychotic medication. Conversely, some people taking medications with a stimulant effect such as the SNRI antidepressants Effexor (venlafaxine) or Wellbutrin (bupropion) may seek out benzodiazepines or opioid narcotics to counter the anxiety and insomnia that such medications sometimes evoke.

Some studies show that nicotine administration can be effective for reducing motor side-effects of antipsychotics, with both bradykinesia (stiff muscles) and dyskinesia(involuntary movement) being prevented.

No specific treatment is available. Management is only supportive and preventive.

Those who are diagnosed with the disease often die within the first few months of life. Almost all children with the disease die by the age of three.

The individual should consult the doctor if their symptoms worsen to prevent any major complications of the condition.

Avoid alcohol—avoid alcohol consumption during the duration of the illness, because alcohol may increase stress on the already strained heart and can make symptoms worse.

Increase consumption of foods rich in selenium—eat foods rich in selenium to help the individual’s heart heal more quickly (in addition to any supplements they may also be taking).

Monitor side effects to medications—if the patient was prescribed with medication, it may be helpful if they can monitor any side effects they have (if they are present) and see their doctor if the side effects are more than just the mildly common ones.

Increase sleep—it is important to get an adequate rest due to poor heart condition. In the case of mild Keshan's disease caused by a viral agent, the individuals doctor will advise them to have complete rest (and adequate fluids) for a specific period to help their body's immune system fight the infection and heal.

Supplements—an individual will most likely be prescribed selenium supplements (in the form of selenomethionine) or have injections of this mineral.

Surgery—if surgery has been advised (implants, stents or full heart transplant) the individual cardiac specialist will advise you about the pre-operative and post-operative care that they will need to undergo and how to best take care of themselves during this time, to avoid complications or worsening of any symptoms or the hhealth.

The treatment for Keshan disease is selenium supplementation. The recommended amounts are fifty-five micrograms of selenium per day for adult men and women, sixty micrograms a day for women during pregnancy and seventy micrograms per day for women after pregnancy. A doctor may insist that if a man is sexually active, he may have to take up to seventy micrograms of selenium per day. A doctor may also recommend that the individual take vitamin E; selenium and vitamin E are medically linked and seem to work to together. An individual will also be advised to have a diet that includes seafood, meats such as kidney, and liver, and some grains and seeds; all of these are high in selenium. Brewer's yeast and wheat germ both contain high levels of selenium. Garlic, onions, mushroom, broccoli, tomatoes, radishes, and Swiss chard may be good sources of selenium if the soil in which they are grown contains it. An individual will have to be monitored once they begin to take the selenium supplements, due to the fact that too much of it can cause balding, intestinal distress, weakness, and slow mental functioning. Individuals in China with the disease treat it with a herb called "Astragalus", which accumulates selenium from the soil.

There are 4 aspects to the treatment of angular cheilitis. Firstly, potential reservoirs of infection inside the mouth are identified and treated. Oral candidiasis, especially denture-related stomatitis is often found to be present where there is angular cheilitis, and if it is not treated, the sores at the corners of the mouth may often recur. This involves having dentures properly fitted and disinfected. Commercial preparations are marketed for this purpose, although dentures may be left in dilute (1:10 concentration) household bleach overnight, but only if they are entirely plastic and do not contain any metal parts, and with rinsing under clean water before use. Improved denture hygiene is often required thereafter, including not wearing the denture during sleep and cleaning it daily. For more information, see Denture-related stomatitis.

Secondly, there may be a need to increase the vertical dimension of the lower face to prevent overclosure of the mouth and formation of deep skin folds. This may require the construction of a new denture with an adjusted bite. Rarely, in cases resistant to normal treatments, surgical procedures such as collagen injections (or other facial fillers such as autologous fat or crosslinked hyaluronic acid) are used in an attempt to restore the normal facial contour. Other measures which seek to reverse the local factors that may be contributing to the condition include improving oral hygiene, stopping smoking or other tobacco habits and use of a barrier cream (e.g. zinc oxide paste) at night.

Thirdly, treatment of the infection and inflammation of the lesions themselves is addressed. This is usually with topical antifungal medication, such as clotrimazole, amphotericin B, ketoconazole, or nystatin cream. Some antifungal creams are combined with corticosteroids such as hydrocortisone or triamcinolone to reduce inflammation, and certain antifungals such as miconazole also have some antibacterial action. Diiodohydroxyquinoline is another topical therapy for angular cheilitis. If "Staphylococcus aureus" infection is demonstrated by microbiological culture to be responsible (or suspected), the treatment may be changed to fusidic acid cream, an antibiotic which is effective against this type of bacteria. Aside from fusidic acid, neomycin, mupirocin, metronidazole, and chlorhexidine are alternative options in this scenario.

Finally, if the condition appears resistant to treatment, investigations for underlying causes such as anemia or nutrient deficiencies or HIV infection. Identification of the underlying cause is essential for treating chronic cases. The lesions may resolve when the underlying disease is treated, e.g. with a course of oral iron or B vitamin supplements. Patch testing is recommended by some in cases which are resistant to treatment and where allergic contact dermatitis is suspected.

Since phytanic acid is not produced in the human body, individuals with Refsum disease are commonly placed on a phytanic acid-restricted diet and avoid the consumption of fats from ruminant animals and certain fish, such as tuna, cod, and haddock. Grass feeding animals and their milk are also avoided. Recent research has shown that CYP4 isoform enzymes could help reduce the over-accumulation of phytanic acid "in vivo". Plasmapheresis is another medical intervention used to treat patients. This involves the filtering of blood to ensure there is no accumulation of phytanic acid.

In ruminant animals, the gut fermentation of consumed plant materials liberates phytol, a constituent of chlorophyll, which is then converted to phytanic acid and stored in fats. Although humans cannot derive significant amounts of phytanic acid from the consumption of chlorophyll present in plant materials, it has been proposed that the great apes (bonobos, chimpanzees, gorillas, and orangutans) can derive significant amounts of phytanic acid from the hindgut fermentation of plant materials.

Avoiding allergens will help prevent symptoms. Allergies that a child has to the family pet can be controlled by removing the animal and finding it a new home. Exterminating cockroaches, mice and rats and a thorough cleaning can reduce symptoms of an allergy in children. Dust mites are attracted to moisture. They consume human skin that has come off and lodged in, furniture, rugs, mattresses, box springs, and pillows. The child's bedding can be covered with allergen-proof covers. Laundering of the child's clothing, bed linens and blankets will also reduce exposure.

Exposure to allergens outside the home can be controlled with the use of air conditioners. Washing the hair, taking a bath or shower before bedtime can be done to remove allergens that have been picked up from outside the home. If grass or grass pollen is an allergen it is sometimes beneficial to remain indoors while grass is being cut or mowed. Children with allergies to grass can avoid playing in the grass to prevent allergic symptoms. Staying out of piled leaves in the fall can help. Pets returning into the home after being outdoors may track in allergens.

Most cases of angular cheilitis respond quickly when antifungal treatment is used. In more long standing cases, the severity of the condition often follows a relapsing and remitting course over time. The condition can be difficult to treat and can be prolonged.

Antibiotics are the primary treatment. The specific approach to their use is dependent on the individual affected and the stage of the disease. For most people with early localized infection, oral administration of doxycycline is widely recommended as the first choice, as it is effective against not only "Borrelia" bacteria but also a variety of other illnesses carried by ticks. Doxycycline is contraindicated in children younger than eight years of age and women who are pregnant or breastfeeding; alternatives to doxycycline are amoxicillin, cefuroxime axetil, and azithromycin. Individuals with early disseminated or late infection may have symptomatic cardiac disease, refractory Lyme arthritis, or neurologic symptoms like meningitis or encephalitis. Intravenous administration of ceftriaxone is recommended as the first choice in these cases; cefotaxime and doxycycline are available as alternatives.

These treatment regimens last from one to four weeks. If joint swelling persists or returns, a second round of antibiotics may be considered. Outside of that, a prolonged antibiotic regimen lasting more than 28 days is not recommended as no clinical evidence shows it to be effective. IgM and IgG antibody levels may be elevated for years even after successful treatment with antibiotics. As antibody levels are not indicative of treatment success, testing for them is not recommended.

A vast number of traditional herbal remedies were recommended for "rheumatism". Modern medicine, both conventional and alternative, recognises that the different rheumatic disorders have different causes (and several of them have multiple causes) and require different kinds of treatment.

Nevertheless, initial therapy of the major rheumatological diseases is with analgesics, such as paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs), members of which are ibuprofen and naproxen. Often, stronger analgesics are required.

The ancient Greeks recorded that bee venom had some beneficial effects on some types of rheumatism. Bee and ant stings were known as a folk remedy in the late 19th century, and at least one physician developed a treatment consisting of repeated formic acid injections. Certain Amazonian tribes, including the Zo'é, use fire ant stings as a remedy for aches and pains.

Cod liver oil has also been used as a remedy.

Neem Tree Oil according to East Indian cultures has also been used as a remedy.

Treatment of VAD can be undertaken with both oral and injectable forms, generally as vitamin A palmitate.

- As an oral form, the supplementation of vitamin A is effective for lowering the risk of morbidity, especially from severe diarrhea, and reducing mortality from measles and all-cause mortality. Vitamin A supplementation of children under five who are at risk of VAD can reduce all‐cause mortality by 23%. Some countries where VAD is a public-health problem address its elimination by including vitamin A supplements available in capsule form with national immunization days (NIDs) for polio eradication or measles. Additionally, the delivery of vitamin A supplements, during integrated child health events such as child health days, have helped ensure high coverage of vitamin A supplementation in a large number of least developed countries. Child health events enable many countries in West and Central Africa to achieve over 80% coverage of vitamin A supplementation. According to UNICEF data, in 2013 worldwide, 65% of children between the ages of 6 and 59 months were fully protected with two high-dose vitamin A supplements. Vitamin A capsules cost about US$0.02. The capsules are easy to handle; they do not need to be stored in a refrigerator or vaccine carrier. When the correct dosage is given, vitamin A is safe and has no negative effect on seroconversion rates for oral polio or measles vaccines. However, because the benefit of vitamin A supplements is transient, children need them regularly every four to six months. Since NIDs provide only one dose per year, NIDs-linked vitamin A distribution must be complemented by other programs to maintain vitamin A in children Maternal high supplementation benefits both mother and breast-fed infant: high-dose vitamin A supplementation of the lactating mother in the first month postpartum can provide the breast-fed infant with an appropriate amount of vitamin A through breast milk. However, high-dose supplementation of pregnant women should be avoided because it can cause miscarriage and birth defects.

- Food fortification is also useful for improving VAD. A variety of oily and dry forms of the retinol esters, retinyl acetates, and retinyl palmitate are available for food fortification of vitamin A. Margarine and oil are the ideal food vehicles for vitamin A fortification. They protect vitamin A from oxidation during storage and prompt absorption of vitamin A. Beta-carotene and retinyl acetate or retinyl palmitate are used as a form of vitamin A for vitamin A fortification of fat-based foods. Fortification of sugar with retinyl palmitate as a form of vitamin A has been used extensively throughout Central America. Cereal flours, milk powder, and liquid milk are also used as food vehicles for vitamin A fortification. Genetic engineering is another method of food fortification, and this has been achieved with golden rice, but opposition to genetically modified foods has prevented its use as of July 2012.

- Dietary diversification can also control VAD. Nonanimal sources of vitamin A which contain preformed vitamin A account for greater than 80% of intake for most individuals in the developing world. The increase in consumption of vitamin A-rich foods of animal origin in addition to fruits and vegetables has beneficial effects on VAD. Researchers at the U. S. Agricultural Research Service have been able to identify genetic sequences in corn that are associated with higher levels of beta-carotene, the precursor to vitamin A. They found that breeders can cross certain variations of corn to produce a crop with an 18-fold increase in beta-carotene. Such advancements in nutritional plant breeding could one day aid in the illnesses related to VAD in developing countries.

Sufficient vitamin D levels can also be achieved through dietary supplementation and/or exposure to sunlight. Vitamin D (cholecalciferol) is the preferred form since it is more readily absorbed than vitamin D. Most dermatologists recommend vitamin D supplementation as an alternative to unprotected ultraviolet exposure due to the increased risk of skin cancer associated with sun exposure. Endogenous production with full body exposure to sunlight is approximately 250 µg (10,000 IU) per day.

According to the American Academy of Pediatrics (AAP), all infants, including those who are exclusively breast-fed, may need vitamin D supplementation until they start drinking at least of vitamin D-fortified milk or formula a day.

Walker–Warburg syndrome (WWS), also called Warburg syndrome, Chemke syndrome, HARD syndrome (Hydrocephalus, Agyria and Retinal Dysplasia), Pagon syndrome, cerebroocular dysgenesis (COD) or cerebroocular dysplasia-muscular dystrophy syndrome (COD-MD), is a rare form of autosomal recessive congenital muscular dystrophy. It is associated with brain (lissencephaly, hydrocephalus, cerebellar malformations) and eye abnormalities. This condition has a worldwide distribution. The overall incidence is unknown but a survey in North-eastern Italy has reported an incidence rate of 1.2 per 100,000 live births. It is the most severe form of congenital muscular dystrophy with most children dying before the age of three years.

There is no cure for EEE. Treatment consists of corticosteroids, anticonvulsants, and supportive measures (treating symptoms) such as intravenous fluids, tracheal intubation, and antipyretics. About four percent of humans known to be infected develop symptoms, with a total of about six cases per year in the US. A third of these cases die, and many survivors suffer permanent brain damage.

Treatment involves increasing dietary intake of calcium, phosphates and vitamin D. Exposure to ultraviolet B light (most easily obtained when the sun is highest in the sky), cod liver oil, halibut-liver oil, and viosterol are all sources of vitamin D.

A sufficient amount of ultraviolet B light in sunlight each day and adequate supplies of calcium and phosphorus in the diet can prevent rickets. Darker-skinned people need to be exposed longer to the ultraviolet rays. The replacement of vitamin D has been proven to correct rickets using these methods of ultraviolet light therapy and medicine.

Recommendations are for 400 international units (IU) of vitamin D a day for infants and children. Children who do not get adequate amounts of vitamin D are at increased risk of rickets. Vitamin D is essential for allowing the body to uptake calcium for use in proper bone calcification and maintenance.

The cat must have a supply of niacin, as cats cannot convert tryptophan into niacin like dogs. However, diets high in corn and low in protein can result in skin lesions and scaly, dry, greasy skin, with hair loss. Another B vitamin, biotin, if deficient causes hair loss around the eyes and face. A lack of B vitamins can be corrected by supplementing with a vitamin B complex, and brewers yeast.

The disease can be prevented in horses with the use of vaccinations. These vaccinations are usually given together with vaccinations for other diseases, most commonly WEE, VEE, and tetanus. Most vaccinations for EEE consist of the killed virus. For humans there is no vaccine for EEE so prevention involves reducing the risk of exposure. Using repellent, wearing protective clothing, and reducing the amount of standing water is the best means for prevention

Cats cannot synthesize vitamin A from plant beta-carotene, and therefore must be supplemented with retinol from meat. A deficiency in vitamin A will result in a poor coat, with hair loss, with scaly and thickened skin. However an excess of vitamin A, called hypervitaminosis A, can result from over feeding cod liver oil, and large amounts of liver. Signs of hypervitaminosis A are overly sensitive skin, and neck pain causing the cat to be unwilling to groom its self, resulting in a poor coat. Supplementing vitamin A with retinol to a deficient cat, and feeding a balanced diet to a cat with hypervitaminosis A will treat the underlying nutritional disorder.

There is no treatment necessary for any type of COD. Diagnosis is important so that the treating doctor does not confuse it for another periapical disease such as rarefying osteitis or condensing osteitis. Incorrect diagnosis could lead to unnecessary root canal treatments. It can be diagnosed by radiographic appearance. Confirming the tooth is vital, as is noting the demographic (African American females).

Cemento-osseous dysplasia (COD) is a benign condition of the jaws that may arise from the fibroblasts of the periodontal ligaments. It is most common in African-American females. The three types are periapical cemental dysplasia (common in those of African descent), focal cemento-osseous dysplasia (Caucasians), and florid cemento-osseous dysplasia (African descent). Periapical occurs most commonly in the mandibular anterior teeth while focal appears predominantly in the mandibular posterior teeth and florid in both maxilla and mandible in multiple quadrants.

For early cases, prompt treatment is usually curative. However, the severity and treatment of Lyme disease may be complicated due to late diagnosis, failure of antibiotic treatment, and simultaneous infection with other tick-borne diseases (coinfections), including ehrlichiosis, babesiosis, and immune suppression in the patient.

It is believed that less than 5% of people have lingering symptoms of fatigue, pain, or joint and muscle aches at the time they finish treatment. These symptoms can last for more than 6 months. This condition is called post-treatment lyme disease syndrome. As of 2016 the reason for the lingering symptoms was not known; the condition is generally managed similarly to fibromyalgia or chronic fatigue syndrome.

In dogs, a serious long-term prognosis may result in glomerular disease, which is a category of kidney damage that may cause chronic kidney disease. Dogs may also experience chronic joint disease if the disease is left untreated. However, the majority of cases of Lyme disease in dogs result in a complete recovery with, and sometimes without, treatment with antibiotics. In rare cases, Lyme disease can be fatal to both humans and dogs.

For the worm, humans are a dead-end host. "Anisakis" and "Pseudoterranova" larvae cannot survive in humans, and eventually die. In some cases, the infection resolves with only symptomatic treatment. In other cases, however, infection can lead to small bowel obstruction, which may require surgery, although treatment with albendazole alone (avoiding surgery) has been reported to be successful. Intestinal perforation (an emergency) is also possible.

Global efforts to support national governments in addressing VAD are led by the Global Alliance for Vitamin A (GAVA), which is an informal partnership between A2Z, the Canadian International Development Agency, Helen Keller International, Micronutrient Initiative, UNICEF, USAID, and the World Bank. Joint GAVA activity is coordinated by the Micronutrient Initiative.

Vitamin Angels has committed itself to eradicating childhood blindness due to VAD on the planet by the year 2020. Operation 20/20 was launched in 2007 and will cover 18 countries. The program gives children two high-dose vitamin A and antiparasitic supplements (twice a year for four years), which provides children with enough of the nutrient during their most vulnerable years to prevent them from going blind and suffering from other life-threatening diseases related to VAD.

About 75% the vitamin A required for supplementation activity by developing countries is supplied by the Micronutrient Initiative with support from the Canadian International Development Agency.

An estimated 1.25 million deaths due to VAD have been averted in 40 countries since 1998.

In 2008, an estimated annual investment of US$60 million in vitamin A and zinc supplementation combined would yield benefits of more than US$1 billion per year, with every dollar spent generating benefits of more than US$17. These combined interventions were ranked by the Copenhagen Consensus 2008 as the world’s best development investment.