Five medications are currently used to treat the cognitive problems of AD: four are acetylcholinesterase inhibitors (tacrine, rivastigmine, galantamine and donepezil) and the other (memantine) is an NMDA receptor antagonist. The benefit from their use is small. No medication has been clearly shown to delay or halt the progression of the disease.

Reduction in the activity of the cholinergic neurons is a well-known feature of Alzheimer's disease. Acetylcholinesterase inhibitors are employed to reduce the rate at which acetylcholine (ACh) is broken down, thereby increasing the concentration of ACh in the brain and combating the loss of ACh caused by the death of cholinergic neurons. There is evidence for the efficacy of these medications in mild to moderate Alzheimer's disease, and some evidence for their use in the advanced stage. The use of these drugs in mild cognitive impairment has not shown any effect in a delay of the onset of AD. The most common side effects are nausea and vomiting, both of which are linked to cholinergic excess. These side effects arise in approximately 10–20% of users, are mild to moderate in severity, and can be managed by slowly adjusting medication doses. Less common secondary effects include muscle cramps, decreased heart rate (bradycardia), decreased appetite and weight, and increased gastric acid production.

Glutamate is an excitatory neurotransmitter of the nervous system, although excessive amounts in the brain can lead to cell death through a process called excitotoxicity which consists of the overstimulation of glutamate receptors. Excitotoxicity occurs not only in Alzheimer's disease, but also in other neurological diseases such as Parkinson's disease and multiple sclerosis. Memantine is a noncompetitive NMDA receptor antagonist first used as an anti-influenza agent. It acts on the glutamatergic system by blocking NMDA receptors and inhibiting their overstimulation by glutamate. Memantine has been shown to have a small benefit in the treatment of Alzheimer's disease. Reported adverse events with memantine are infrequent and mild, including hallucinations, confusion, dizziness, headache and fatigue. The combination of memantine and donepezil has been shown to be "of statistically significant but clinically marginal effectiveness".

Atypical antipsychotics are modestly useful in reducing aggression and psychosis in people with Alzheimer's disease, but their advantages are offset by serious adverse effects, such as stroke, movement difficulties or cognitive decline. When used in the long-term, they have been shown to associate with increased mortality. Stopping antipsychotic use in this group of people appears to be safe.

Huperzine A while promising, requires further evidence before its use can be recommended.

There is no cure for Alzheimer's disease; available treatments offer relatively small symptomatic benefit but remain palliative in nature. Current treatments can be divided into pharmaceutical, psychosocial and caregiving.

Tolcapone inhibits the activity COMT, an enzyme which degrades dopamine. It has been used to complement levodopa; however, its usefulness is limited by possible complications such as liver damage. A similarly effective drug, entacapone, has not been shown to cause significant alterations of liver function. Licensed preparations of entacapone contain entacapone alone or in combination with carbidopa and levodopa.

The motor symptoms of PD are the result of reduced dopamine production in the brain's basal ganglia. Dopamine does not cross the blood-brain barrier, so it cannot be taken as a medicine to boost the brain's depleted levels of dopamine. However a precursor of dopamine, levodopa, can pass through to the brain where it is readily converted to dopamine, and administration of levodopa temporarily diminishes the motor symptoms of PD. Levodopa has been the most widely used PD treatment for over 40 years.

Only 5–10% of levodopa crosses the blood–brain barrier. Much of the remainder is metabolized to dopamine elsewhere in the body, causing a variety of side effects including nausea, vomiting and orthostatic hypotension. Carbidopa and benserazide are dopa decarboxylase inhibitors which do not cross the blood-brain barrier and inhibit the conversion of levodopa to dopamine outside the brain, reducing side effects and improving the availability of levodopa for passage into the brain. One of these drugs is usually taken along with levodopa, often combined with levodopa in the same pill.

Levodopa use leads in the long term to the development of complications: involuntary movements called dyskinesias, and fluctuations in the effectiveness of the medication. When fluctuations occur, a person can cycle through phases with good response to medication and reduced PD symptoms ("on" state), and phases with poor response to medication and significant PD symptoms ("off" state). Using lower doses of levodopa may reduce the risk and severity of these levodopa-induced complications. A former strategy to reduce levodopa-related dyskinesia and fluctuations was to withdraw levodopa medication for some time. This is now discouraged since it can bring on dangerous side effects such as neuroleptic malignant syndrome. Most people with PD will eventually need levodopa and will later develop levodopa-induced fluctuations and dyskinesias.

There are controlled-release versions of levodopa. Older controlled-release levodopa preparations have poor and unreliable absorption and bioavailability and have not demonstrated improved control of PD motor symptoms or a reduction in levodopa-related complications when compared to immediate release preparations. A newer extended-release levodopa preparation does seem to be more effective in reducing fluctuations but in many patients problems persist. Intestinal infusions of levodopa (Duodopa) can result in striking improvements in fluctuations compared to oral levodopa when the fluctuations are due to insufficient uptake caused by gastroparesis. Other oral, longer acting formulations are under study and other modes of delivery (inhaled, transdermal) are being developed.

Pharmaceutical management, as with Parkinson's disease, involves striking a balance between treating the motor, emotive, and cognitive symptoms. Motor symptoms appear to respond somewhat to the medications used to treat Parkinson's disease (e.g. levodopa), while cognitive issues may improve with medications for Alzheimer's disease such as donepezil. Medications used in the treatment of ADHD (e.g. methylphenidate) might improve cognition or daytime sleepiness; however, medications for both Parkinson's disease and ADHD increase levels of the chemical dopamine in the brain, so increase the risk of hallucinations with those classes of pharmaceuticals.

Treatment of the movement and cognitive portions of the disease may worsen hallucinations and psychosis, while treatment of hallucinations and psychosis with antipsychotics may worsen parkinsonian or ADHD symptoms in DLB, such as tremor or rigidity and lack of concentration or impulse control. Physicians may find the use of cholinesterase inhibitors represents the treatment of choice for cognitive problems and donepezil (Aricept), rivastigmine (Exelon), and galantamine (Reminyl) may be recommended as a means to help with these problems and to slow or prevent the decline of cognitive function. DLB may be more responsive to donepezil than Alzheimer's disease. Memantine also may be useful. Levocarb may help with movement problems, but in some cases, as with dopamine agonists, may tend to aggravate psychosis in people with DLB. Clonazepam may help with rapid eye movement behavior disorder; table salt or antihypotensive medications may help with fainting and other problems associated with orthostatic hypotension. Botulinum toxin injections in the parotid glands may help with sialorrhea. Other medications, especially stimulants such as the ADHD drug methylphenidate (Ritalin) and modafinil, may improve daytime alertness, but as with the antiparkinsonian drug Levocarb, antihyperkinetics such as Ritalin increase the risk of psychosis. Experts advise extreme caution in the use of antipsychotic medication in people with DLB because of their sensitivity to these agents. When these medications must be used, atypical antipsychotics are preferred to typical antipsychotics; a very low dose should be tried initially and increased slowly, and patients should be carefully monitored for adverse reactions to the medications.

Due to hypersensitivity to neuroleptics, preventing DLB patients from taking these medications is important. People with DLB are at risk for neuroleptic malignant syndrome, a life-threatening illness, because of their sensitivity to these medications, especially the older typical antipsychotics, such as haloperidol. Other medications, including medications for urinary incontinence and the antihistamine medication diphenhydramine (Benadryl), also may worsen confusion.

No medications have been shown to prevent or cure dementia. Medications may be used to treat the behavioural and cognitive symptoms but have no effect on the underlying disease process.

Acetylcholinesterase inhibitors, such as donepezil, may be useful for Alzheimer disease and dementia in Parkinson's, DLB, or vascular dementia. The quality of the evidence however is poor and the benefit is small. No difference has been shown between the agents in this family. In a minority of people side effects include a slow heart rate and fainting.

As assessment for an underlying cause of the behavior is a needed before prescribing antipsychotic medication for symptoms of dementia. Antipsychotic drugs should be used to treat dementia only if non-drug therapies have not worked, and the person's actions threaten themselves or others. Aggressive behavior changes are sometimes the result of other solvable problems, that could make treatment with antipsychotics unnecessary. Because people with dementia can be aggressive, resistant to their treatment, and otherwise disruptive, sometimes antipsychotic drugs are considered as a therapy in response. These drugs have risky adverse effects, including increasing the patient's chance of stroke and death. Generally, stopping antipsychotics for people with dementia does not cause problems, even in those who have been on them a long time.

N-methyl-D-aspartate (NMDA) receptor blockers such as memantine may be of benefit but the evidence is less conclusive than for AChEIs. Due to their differing mechanisms of action memantine and acetylcholinesterase inhibitors can be used in combination however the benefit is slight.

While depression is frequently associated with dementia, selective serotonin reuptake inhibitors (SSRIs) do not appear to affect outcomes.

The use of medications to alleviate sleep disturbances that people with dementia often experience has not been well researched, even for medications that are commonly prescribed. In 2012 the American Geriatrics Society recommended that benzodiazepines such as diazepam, and non-benzodiazepine hypnotics, be avoided for people with dementia due to the risks of increased cognitive impairment and falls. Additionally, there is little evidence for the effectiveness of benzodiazepines in this population. There is no clear evidence that melatonin or ramelteon improves sleep for people with dementia due to Alzheimer's disease. There is limited evidence that a low dose of trazodone may improve sleep, however more research is needed.

There is no solid evidence that folate or vitamin B12 improves outcomes in those with cognitive problems. Statins also have no benefit in dementia. Medications for other health conditions may need to be managed differently for a person who also has a diagnosis of dementia. The MATCH-D criteria can help identify ways that a diagnosis of dementia changes medication management for other health conditions. It is unclear if there is a link between blood pressure medication and dementia. There is a possibility that people may experience an increase in cardiovascular-related events if these medications are withdrawn.

No cure for dementia with Lewy bodies is known. Treatment may offer symptomatic benefit, but remains palliative in nature. Current treatment modalities are divided into pharmaceutical and caregiving.

Aromatherapy and massage have unclear evidence. There have been studies on the efficacy and safety of cannabinoids in relieving behavioral and psychological symptoms of dementia.

Omega-3 fatty acid supplements from plants or fish sources do not appear to benefit or harm people with mild to moderate Alzheimer's disease. It is unclear if taking omega-3 fatty acid supplements can improve other types of dementia.

Binswanger's disease has no cure and has been shown to be the most severe impairment of all of the vascular dementias. The best way to manage the vascular risk factors that contribute to poor perfusion in the brain is to treat the cause, such as chronic hypertension or diabetes. It has been shown that current Alzheimer’s medication, donepezil (trade name Aricept), may help Binswanger’s Disease patients as well . Donepezil increases the acetylcholine in the brain through a choline esterase inhibitor which deactivates the enzyme that breaks down acetylcholine. Alzheimer as well as Binswanger patients have low levels of acetylcholine and this helps to restore the normal levels of neurotransmitters in the brain. This drug may improve memory, awareness, and the ability to function. If no medical interception of the disease is performed then the disease will continue to worsen as the patient ages due to the continuing atrophy of the white matter from whatever was its original cause.

Because the exact cause of CBD is unknown, there exists no formal treatment for the disease. Instead, treatments focus on minimizing the appearance or effect of the symptoms resulting from CBD. The most easily treatable symptom of CBD is parkinsonism, and the most common form of treatment for this symptom is the application of dopaminergic drugs. However, in general only moderate improvement is seen and the relief from the symptom is not long-lasting. In addition, palliative therapies, including the implementation of wheelchairs, speech therapy, and feeding techniques, are often used to alleviate many of the symptoms that show no improvement with drug administration.

Currently, there are no medications that have been approved specifically for prevention or treatment of vascular dementia. The use of medications for treatment of Alzheimer's dementia, such as cholinesterase inhibitors and memantine, has shown small improvement of cognition in vascular dementia. This is most likely due to the drugs' actions on co-existing AD-related pathology. Multiple studies found a small benefit in VaD treatment with: memantine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist; cholinesterase inhibitors galantamine, donepezil, rivastigmine; and ginkgo biloba extract.

The general management of dementia includes referral to community services, aid with judgment and decision-making regarding legal and ethical issues (e.g., driving, capacity, advance directives), and consideration of caregiver stress.

Behavioral and affective symptoms deserve special consideration in this patient group. These problems tend to be resistant to conventional psychopharmacological treatment and often lead to hospital admission and placement in permanent care.

No specific treatment for CADASIL is available. While most treatments for CADASIL patients' symptoms – including migraine and stroke – are similar to those without CADASIL, these treatments are almost exclusively empiric, as data regarding their benefit to CADASIL patients is limited. Antiplatelet agents such as aspirin, dipyridamole, or clopidogrel might help prevent strokes; however, anticoagulation may be inadvisable given the propensity for microhemorrhages. Control of high blood pressure is particularly important in CADASIL patients. Short-term use of atorvastatin, a statin-type cholesterol-lowering medication, has not been shown to be beneficial in CADASIL patients' cerebral hemodynamic parameters, although treatment of comorbidities such as high cholesterol is recommended. Stopping oral contraceptive pills may be recommended. Some authors advise against the use of triptan medications for migraine treatment, given their vasoconstrictive effects, although this sentiment is not universal. As with other individuals, people with CADASIL should be encouraged to quit smoking.

In one small study, around 1/3 of patients with CADASIL were found to have cerebral microhemorrhages (tiny areas of old blood) on MRI.

L-arginine, a naturally occurring amino acid, has been proposed as a potential therapy for CADASIL, but as of 2017 there are no clinical studies supporting its use. Donepezil, normally used for Alzheimer's Disease, was not shown not to improve executive functioning in CADASIL patients.

Specific and accepted scientific treatment for PCA has yet to be discovered; this may be due to the rarity and variations of the disease. At times PCA patients are treated with prescriptions originally created for treatment of AD such as, cholinesterase inhibitors, Donepezil, Rivastigmine and Galantamine, and Memantine. Antidepressant drugs have also provided some positive effects.

Patients may find success with non-prescription treatments such as psychological treatments. PCA patients may find assistance in meeting with an occupational therapist or sensory team for aid in adapting to the PCA symptoms, especially for visual changes. People with PCA and their caregivers are likely to have different needs to more typical cases of Alzheimer's disease, and may benefit from specialized support groups such as the PCA Support Group based at University College London, or other groups for young people with dementia. No study to date has been definitive to provide accepted conclusive analysis on treatment options.

Parkinson-plus syndromes are usually more rapidly progressive and less likely to respond to antiparkinsonian medication than PD. However, the additional features of the diseases may respond to medications not used in PD.

Current therapy for Parkinson-plus syndromes is centered around a multidisciplinary treatment of symptoms.

These disorders have been linked to pesticide exposure.

Early detection and accurate diagnosis are important, as vascular dementia is at least partially preventable. Ischemic changes in the brain are irreversible, but the patient with vascular dementia can demonstrate periods of stability or even mild improvement.

Since stroke is an essential part of vascular dementia, the goal is to prevent new strokes. This is attempted through reduction of stroke risk factors, such as high blood pressure, high blood lipid levels, atrial fibrillation, or diabetes mellitus. Meta-analyses have found that medications for high blood pressure are effective at prevention of pre-stroke dementia, which means that high blood pressure treatment should be started early. These medications include angiotensin converting enzyme inhibitors, diuretics, calcium channel blockers, sympathetic nerve inhibitors, angiotensin II receptor antagonists or adrenergic antagonists. Elevated lipid levels, including HDL, were found to increase risk of vascular dementia. However, four large recent reviews showed that therapy with statin drugs was ineffective in treatment or prevention of this dementia. Aspirin is a medication that is commonly prescribed for prevention of strokes and heart attacks; it is also frequently given to patients with dementia. However, its efficacy in slowing progression of dementia or improving cognition has not been supported by studies. Smoking cessation and Mediterranean diet have not been found to help patients with cognitive impairment, however physical activity was consistently the most effective method of preventing cognitive decline.

The process of neurodegeneration is not well understood, so the diseases that stem from it have, as yet, no cures. In the search for effective treatments (as opposed to palliative care), investigators employ animal models of disease to test potential therapeutic agents. Model organisms provide an inexpensive and relatively quick means to perform two main functions: target identification and target validation. Together, these help show the value of any specific therapeutic strategies and drugs when attempting to ameliorate disease severity. An example is the drug Dimebon (Medivation). This drug is in phase III clinical trials for use in Alzheimer's disease, and also recently finished phase II clinical trials for use in Huntington's disease. In March 2010, the results of a clinical trial phase III were released; the investigational Alzheimer's disease drug Dimebon failed in the pivotal CONNECTION trial of patients with mild-to-moderate disease. With CONCERT, the remaining Pfizer and Medivation Phase III trial for Dimebon (latrepirdine) in Alzheimer's disease failed in 2012, effectively ending the development in this indication.

In another experiment using a rat model of Alzheimer's disease, it was demonstrated that systemic administration of hypothalamic proline-rich peptide (PRP)-1 offers neuroprotective effects and can prevent neurodegeneration in hippocampus amyloid-beta 25–35. This suggests that there could be therapeutic value to PRP-1.

Protein degradation offers therapeutic options both in preventing the synthesis and degradation of irregular proteins. There is also interest in upregulating autophagy to help clear protein aggregates implicated in neurodegeneration. Both of these options involve very complex pathways that we are only beginning to understand.

The goal of immunotherapy is to enhance aspects of the immune system. Both active and passive vaccinations have been proposed for Alzheimer's disease and other conditions, however more research must be done to prove safety and efficacy in humans.

there are no USFDA-approved medications for the treatment of mild cognitive impairment. Moreover, as of January 2018, there is no high-quality evidence that supports the efficacy of any pharmaceutical drugs or dietary supplements for improving cognitive symptoms in individuals with mild cognitive impairment. A moderate amount of high-quality evidence supports the efficacy of regular physical exercise for improving cognitive symptoms in individuals with MCI. The clinical trials that established the efficacy of exercise therapy for MCI involved twice weekly exercise over a period of six months. A small amount of high-quality evidence supports the efficacy of cognitive training for improving some measures of cognitive function in individuals with mild cognitive impairment. Due to the heterogeneity among studies which assessed the effect of cognitive training in individuals with MCI, there are no particular cognitive training interventions that have been found to provide greater symptomatic benefits for MCI relative to other forms of cognitive training.

The American Academy of Neurology's (AAN) clinical practice guideline on mild cognitive impairment from January 2018 stated that clinicians "should" identify modifiable risk factors in individuals with MCI, assess functional impairments, provide treatment for any behavioral or neuropsychiatric symptoms, and monitor the individual's cognitive status over time. It also stated that medications which cause cognitive impairment "should" be discontinued or avoided if possible. Due to the lack of evidence supporting the efficacy of cholinesterase inhibitors in individuals with MCI, the AAN guideline stated that clinicians who choose to prescribe them for the treatment of MCI "must" inform patients about the lack of evidence supporting this therapy. The guideline also indicated that clinicians "should" recommend that individuals with MCI engage in regular physical exercise for cognitive symptomatic benefits; clinicians "may" also recommend cognitive training, which appears to provide some symptomatic benefit in certain cognitive measures.

As MCI may represent a prodromal state to clinical Alzheimer's disease, treatments proposed for Alzheimer's disease, such as antioxidants and cholinesterase inhibitors, could potentially be useful; however, there is no evidence to support the efficacy of cholinesterase inhibitors for the treatment of mild cognitive impairment. Two drugs used to treat Alzheimer's disease have been assessed for their ability to treat MCI or prevent progression to full Alzheimer's disease. Rivastigmine failed to stop or slow progression to Alzheimer's disease or to improve cognitive function for individuals with mild cognitive impairment; donepezil showed only minor, short-term benefits and was associated with significant side effects.

In a two-year randomized trial of 168 people with MCI given either high-dose vitamins or placebo, vitamins cut the rate of brain shrinkage by up to half. The vitamins were the three B vitamins folic acid, vitamin B6, and vitamin B12, which inhibit production of the amino acid homocysteine. High blood levels of homocysteine are associated with increased risk of cognitive decline, dementia, and cardiovascular disease. A single study from 2012 showed a possible connection between macronutrient intake and development of MCI. It is also suggested that a dietary pattern with relatively high caloric intake from carbohydrates and low caloric intake from fat and proteins may increase the risk of MCI or dementia in elderly persons

Experimental non-pharmacological treatments for MCI include transcranial magnetic stimulation and transcranial direct current stimulation; the efficacy of these interventions for the treatment of MCI has not yet been established.

There is no FDA-approved treatment for agitation in dementia.

Medical treatment may begin with a cholinesterase inhibitor, which appears safer than other alternatives although evidence for its efficacy is mixed. If this does not improve the symptoms, atypical antipsychotics may offer an alternative, although they are effective against agitation only in the short-term while posing a well-documented risk of cerebrovascular events (e.g. stroke). Other possible interventions, such as traditional antipsychotics or antidepressants, are less well studied for this condition.

There is no known cure for PSP and management is primarily supportive. PSP cases are often split into two subgroups, PSP-Richardson, the classic type, and PSP-Parkinsonism, where a short-term response to levodopa can be obtained. Dyskinesia is an occasional but rare complication of treatment. Amantadine is also sometimes helpful. After a few years the Parkinsonian variant tends to take on Richardson features. Other variants have been described. Botox can be used to treat neck dystonia and blephrospasm, but this can aggravate dysphagia.

Two studies have suggested that rivastigmine may help with cognitive aspects, but the authors of both studies have suggested a larger sampling be used. There is some evidence that the hypnotic zolpidem may improve motor function and eye movements, but only from small-scale studies.

In a confirmed medical diagnosis, therapy is used to isolate and begin treating the cause of the disorder. Thereafter, psychiatric medication is used a secondary step in treatment. Medications include antipsychotic, antidepressant, or sedation-inducing, varying on the patients severity.

Treatment of psychorganic syndrome is directed at the main disease. Nootropics like piracetam, have had positive effects on patients. Vitamin therapy, antioxidants, neurotropic, and cerebroprotective have also found to be effective when put on a repeat course.

Currently, there is no cure for FTD. Treatments are available to manage the behavioral symptoms. Disinhibition and compulsive behaviors can be controlled by selective serotonin reuptake inhibitors (SSRIs). Although Alzheimer's and FTD share certain symptoms, they cannot be treated with the same pharmacological agents because the cholinergic systems are not affected in FTD.

Because FTD often occurs in younger people (i.e. in their 40's or 50's), it can severely affect families. Patients often still have children living in the home. Financially, it can be devastating as the disease strikes at the time of life that often includes the top wage-earning years.

Personality changes in individuals with FTD are involuntary. Managing the disease is unique to each individual, as different patients with FTD will display different symptoms, sometimes of rebellious nature.

As of 2015 there was no cure for CJD; some of the symptoms like twitching can be managed but otherwise treatment is palliative care.

Exercise is a promising mechanism of prevention and treatment for various diseases characterized by neuroinflammation. Aerobic exercise is used widely to reduce inflammation in the periphery. Exercise has been shown to decreases proliferation of microglia in the brain, decrease hippocampal expression of immune-related genes, and reduce expression of inflammatory cytokines such as TNF-α.

Patients with PSP usually seek or are referred to occupational therapy, speech-language pathology for motor speech changes typically a spastic-ataxic dysarthria, and physical therapy for balance and gait problems with reports of frequent falls. Evidence-based approaches to rehabilitation in PSP are lacking, and currently the majority of research on the subject consists of case reports involving only a small number of patients.

Case reports of rehabilitation programs for patients with PSP generally include limb-coordination activities, tilt-board balancing, gait training, strength training with progressive resistive exercises and isokinetic exercises and stretching of the neck muscles. While some case reports suggest that physiotherapy can offer improvements in balance and gait of patients with PSP, the results cannot be generalized across all patients with PSP as each case report only followed one or two patients. The observations made from these case studies can be useful, however, in helping to guide future research concerning the effectiveness of balance and gait training programs in the management of PSP.

Individuals with PSP are often referred to occupational therapists to help manage their condition and to help enhance their independence. This may include being taught to use mobility aids. Due to their tendency to fall backwards, the use of a walker, particularly one that can be weighted in the front, is recommended over a cane. The use of an appropriate mobility aid will help to decrease the individual’s risk of falls and make them safer to ambulate independently in the community.

Due to their balance problems and irregular movements individuals will need to spend time learning how to safely transfer in their homes as well as in the community. This may include rising from and sitting in chairs safely.

Due to the progressive nature of this disease, all individuals eventually lose their ability to walk and will need to progress to using a wheelchair. Severe dysphagia often follows, and at this point death is often a matter of months.

There is a wide range of treatments for central nervous system diseases. These can range from surgery to neural rehabilitation or prescribed medications.