Depression

Depression is a very common psychological disturbance people of all age groups face. Some of the features are

• Not deriving pleasure from the usual pleasurable activities (Anhedonia)
• Sadness or low mood (most of the time, most of the days ) and mood changes frequently
• Tiredness – People become fatigue even with minimal work
• Decreased interest and involvement in worldly activities and interaction with other people (isolation/ social withdrawal)
• Decreased sleep& poor quality of sleep or increase in sleep
• Decrease/ Increase in appetite
• Decreased attention and concentration
• Feeling helpless and hopeless
• Having death wishes or suicidal ideations

Depression may vary from mild- severe and at times recur (recurrent depressive disorder) or remain long standing (dysthymia). Sometimes depression may result from brain damage (organic depression) or following delivery of child (postpartum depression).

Anxiety

Fear, nervousness, apprehension, How to name it? It could be with all these names and many more, i.e. a sense of uneasiness and jitteriness (which includes both psychological and physical unrest).

There are so many types of anxiety disorders

• (i) Generalized anxiety disorder
• (ii) Panic Disorder
• (iii) Different kinds of phobias including social phobia agarophobia specific phobias etc

The individual may be aware that his thoughts are irrational but is unable to control/resist it by himself/herself

Somatoform And Dissociative Disorders

An unresolved painful psychological conflict may be experienced as bodily symptoms which are somatization disorders. The same conflicts make the person to experience different conscious states physical disorders.

Dissociative disorders are conditions that involve disruptions or breakdowns of memory, awareness, identity or perception. People with dissociative disorders use dissociation, a defense mechanism, pathologically and involuntarily. Dissociative disorders are thought to be primarily caused by psychological trauma.

Schizophrenia

One of the major mental illnesses the human beings suffer. It is a disorder of one’s, perception, thinking, emotions and behavior. People with this illness will lose touch with reality. They will start experiencing things which are not perceived by others. They hear unreal voices, see unreal things, become suspicious, fearful, paranoid, aggressive, assume odd postures, etc. There are many varieties of schizophrenia including paranoid, catatonic, hebephrenic subtypes. They need intense treatment.

Personality Disorder
Every person has a certain character and tendency to behave in a certain way in a certain situation. This is constructed by one’s genetic maker and from his learning all through his life. The individual may, or may not recognize himself as the cause of the problems and usually has difficulty in adjusting. If the personality is deviant it will result in interpersonal and social adjustments. This is called personality disorder.

Other Disorders

Eating disorders
Due to neurological, endocrine and psychological factors,  people develop different kind of eating disorders, including anorexia nervosa, bulimia nervosa, binge eating, etc

Sleep disorders
Sleep is a biological mechanism which involves many stages, which is associated with different psychological states. Depending upon the disturbance occurring at different stages, one will experience a variety of sleep disorders. It may include insomnia, hypersomnia , narcolepsy, cataplexy, nightmares,  sleep terror, sleep paralysis, sleep walking, sleep talking, bruxism ,etc.

Sexual dysfunction
Human sexual response cycle includes four interlinked stages- desire, arousal, orgasm and resolution.  People may have difficulty in any one of the above mentioned stages resulting in dysfunctions - including sexual desire disorder, sexual aversion disorder which is common to both male and female. Erectile dysfunction and premature ejaculation is predominant among men. Anorgasmia or lack of sexual desire, vaginismus, and disperunia are commonly reported among women. 
There is another dimension of sexual problem which is called sexual deviation including pedophilia, voyeurism, fetishism, sadism and masochism, etc.

Geriatric/Old-age Psychiatric conditions
Elderly people are vulnerable to a variety of psychological disturbances such as: depression, anxiety, psychosis and so on. The most important problem is memory disturbances that range from mild cognitive impairment to different types of Dementias.