Effects of Drug/Alcohol Abuse
1.The immediate effects of drugs/alcohol abuse are manifested as reckless behaviour, vandalism and violence.
2.Excess doses can lead to coma and death due to cerebral haemorrhage, respiratory and heart failure.
3.A combination of drugs or their intake with alcohol leads to death.
4.The most common warning signals of drugs/alcohol abuse include:
(i)Drop in academic performance.
(ii)Lack of interest in personal hygiene.
(iii)Withdrawal and isolation from family and friends.
(iv)Aggressive and rebellious behaviour.
(v)Lack of interest in hobbies.
(vi)Change in sleeping and eating habits.
(vii)Fluctuations in weight, etc.

Major groups of psychotropic drugs,examples and effects

(i) Ascariasis
Cause. It is caused by Ascaris lumbricoides.(round worm).
Symptoms.Its symptoms include:
(a) Blockage of intestinal passage,
(b)Anaemia,
(c)Abdominal/muscular pain,
(d)Internal bleeding,
(e)Nausea and headache.
Modes of transmission. Infection is through contaminated vegetables, fruits and water as eggs of parasite excreted by the infected persons contaminate soil, plants and water
(ii) Filariasis/Elephantiasis
Cause. It is caused by wuchereria bancrofti and wuchereria malayi(filarial worms)
They normally cause inflammation of the organs in which they live for many years.
They normally affect the lymph vessels of the lower limbs (causing them to swell like that of an elephant, hence called elephantiasis).
Genital organs may also be affected leading to gross deformation.
Modes of transmission. The female culex mosquito is the vector.
(iii)Ringworms
Cause. These are caused by fungi like microsporum, Epidermophyton and Trichophyton
Symptoms. The symptoms include
(i) dry scaly lesions on skins, nails and scalp.
(ii)lesions are accompanied by itching.
Modes of transmission. Ringworms are generally acquired from soil or by direct contact with the contaminated articles used by the infected persons.

Cause.It is also called amoebic dysentery.It is caused by a protozoan known as Entamoeba histolytica. 
Mode of Transmission.In this case,the source of infection are cysts from the faecal matter of the infected person.The cysts get into food and reach the stomach.Its incubation period is five days in severe infection and several months in chronic cases.
Symptoms.Mild diarrhoea alternating with constipation.In severe cases dysentery with mucus and blood in stools.Abscesses may be formed in lungs and liver.
Prevention.Proper disposal of faecal matter.protection of sources of drinking water and field sanitation.

Common human diseases

It is true that once a person gets entangled in the deadly whirlpool of alcohol or drugs, it is very difficult to get rid of this habit because, in the absence of a continuous supply of alcohol/drugs, the person starts showing certain symptoms called withdrawal signs which are listed below:
(1) Anxiety  
(2) Shakiness
(3) Nausea  
(4)Sweating.

Treatment of cancer:
The following methods (one or in combination) can help to treat cancer.
(i) Surgery
The tumour cells are surgically removed to reduce the load of cancerous cell.
(ii) Radiotheraphy
The tumour cells are irradiated wholly (but taking care of the surrounding normal cells) with safe doses of radiations.
(iii) Chemotherapy
Certain drugs are used to kill the cancerous cells,but majority of the drugs have side effects like hair fall,anaemia,etc.
(iv) Immunotherapy
This involves the use of biological response-modifiers,like alpha-interferon,which activate the immune system and help in destroying the tumour.

Cancer-Diagnosis:
Cancer can be diagnosed/detected by:
(i) Biopsy and histopathological studies of the tissue.
(ii) Blood and bone marrow tests for increased cell counts as in leukaemia.
(iii) Use of techniques like radiography,Magnetic Resonance Imagine (MRI) and computed tomography (CT) for cancer of internal organs.
(iv) Use of antibodies against cancer specific antigens.
(v) Applying principles of molecular biology to detect genes in individuals with inherited susceptibility to certain types of cancer.

Behavioural changes in a tobacco addicted person
1. Loss of co-ordination of body parts.
2. Alteration in attitude.
3. Amnesia.
4. Restlessness.
It is true that once a person gets entangled in the deadly whirlpool of alcohol or drugs, it is very difficult to get rid of this habit because, in the absence of a continuous supply of alcohol/drugs, the person starts showing certain symptoms called withdrawal signs which are listed below:
(1) Anxiety          
(2) Shakiness
(3) Nausea            
(4) Sweating.