A mental disorder is a syndrome characterized by clinically significant disturbance in an individual’s cognition, emotion, regulation or behaviour that reflects a dysfunction in the psychological, biological or behavioral developmental processes underlying mental functioning. Mental disorders are usually associated with significant distress or disability in social, occupational or other important activities (Diagnostic and statistical manual of mental disorders: DSM-5,2013). Models can also be called approaches. A model is a concept which is frequently used by scientists to explain a process which cannot be directly observed. Psychologists have widely used models to help comprehend the causes of the abnormal behaviour, to inquire, to identify important information and the data and the interpretation of the data (Sue et al., 2010).
It is important to understand mental illness so as to be able to select the appropriate treatment methods for mental illness and models of abnormal behavior help in this function. There are various models of mental illnesses that explain and describe abnormal behaviour, the following paragraphs discusses these models.
To begin with, knowledge about the central nervous system (which is made up of the brain and the spinal cord) structure and how it works is necessary for understanding of the biological model of explaining abnormal behaviour. This model identifies different biological causes of abnormal behavior, particularly involving genetic material and the brain. The brain is made up of billions of neurons that send and receive information. The brain has the right and the left hemispheres and each of them controls the opposite side of the body. Some structures of the brain such as the thalamus, hypothalamus, reticular activating system, limbic system, and cerebrum are very important to abnormal behaviour while other structures in the midbrain and hindbrain produce chemicals that are associated with mental disorders.
Biochemical theories under the biological model are based on the assumption that mental illnesses are caused by chemical imbalances. Neurons differ in their work in the brain and are made up of dendrites and axons. The dendrites receive signals from other neurons while the axons which send the signals to other neurons. Chemical substances known as neurotransmitters are released into the synapse (gap at the end of the axon). Imbalances in specific neurotransmitters in the brain lead to abnormal behaviour. Researches have reported that specific medications have the tendency to lessen symptoms of abnormal behavior by either inhibiting or exciting neurotransmitter activity in the brain. Studies have shown that the genetic makeup plays a major part in describing and explaining how some disorders develop. The interaction between an individual’s genotype (genetic makeup) and the individual’s environment results in the individual’s phenotype which include the physical and behavioral features of that individual.
The Human Genome Project mapped the region of all genes in the nucleus of a human cell and completed its sequencing to give a basic blueprint of the whole genetic material located in each cell of the human body. ‘ The human genome is composed of all the genetic material in the chromosomes of a particular organism and is the most complex instruction manual ever conceived on how the body works’ (Sue et al,2010). Diathesis-stress theory argues that inheritance of a vulnerability to develop a disorder may be triggered by environmental factors called stressors.
The second model is the psychodynamic model also known as the psychoanalytic model. According to Ramsden (2013), the psychodynamic model was developed and revised by Sigmund Freud, is based on two important assumptions: psychic determinisms and the unconscious (Gedo, 1988). Freud was of the view that every human behaviour whether directly observable like a smile or not observable such as a fantasy, existed not by chance but rather as a result of previous mental processes. To Freud, all dimensions of an individual’s behaviour results from previous internal and external experiences and events of the individual. Another assumption of psychoanalytic thinking is the existence of the ‘ Unconscious ‘ which is made up of memories of childhood experiences and informally obtained information that are difficult to remember.
According to Carr (2001), psychoanalytic theory states that primitive sexual and aggressive desires of the unconscious ‘id’ are slowly controlled by rational ‘ego’. Superego: moral judgement, guides the ego. Conflict between sexual and aggressive desires (Id) and moral judgement (superego) result in intrapsychic conflict which are unavoidable. Such conflicts are unconsciously resolved through the use of different defence mechanisms. Defence mechanisms keeps unacceptable sexual and aggressive desires from consciousness. Human personality develops through 5 psychosexual stages each with a specific challenge. Not resolving these challenges will lead to a damaging effect on a person’s personality. Freud emphasizes on the relevance of childhood experiences as he believed that an individual’s personality was greatly determined by first five years of life.
The five stages are during the oral (first year), anal (second year of life), phallic (approximately the third and fourth years of life), latency (approximately six to twelve years of age) and genital (beginning in puberty) stages. Later development is dependent on fixation taking place during each psychosexual stage. Fixation occurs when emotional development gets stuck a particular psychosexual stage. The cognitive model of abnormal behavior assume that conscious thoughts link a person’s emotional state and behaviour in response to a particular stimulus.
Next, is the cognitive theories/ models of mental illness. They are of the view that thoughts and feelings are necessary for change in behaviour. According to this model, people have different labels and explanations to events and situations which has a great influence on their emotional reactions and behaviour. A person’s schema (interpretation given to events) is highly influenced by his experiences, values and capabilities. Cognitive theories focus on irrational and maladaptive ideas and thoughts and distortions of the actual thought process to find the causes of abnormal behavior. Aaron Beck and Albert Ellis define psychological problems as irrational thought patterns that fall outside an individual ’s belief system (Sue et al. 2010).
An individual’s unpleasant emotional reaction to fear, anxiety, etc are consequences of his explanation of events not the event itself. Ellis described an A-B-C process of how an individual develops irrational thoughts where A is an event, B is a belief, and C is a consequent behavior or emotion. Ellis called it the theory of personality. According this theory, the event (A) does not result in the emotional or behavioral response (C) rather, the belief (B) about the event(A) results in (C) the emotional or behavioral response.
Again, the family system model argues that mental problems or abnormal behaviours are maintained by designs of interaction and belief systems inside the family and a more extensive social system of the patient as stated by Carr (2001). Sue et al (2010), purports that the family system model is one of the viewpoints that stress on how our behaviour is affected by other people, particularly those who are significant. The family system model of abnormal behaviour assumes that the whole family system is specifically influenced by the behaviour of one family member. Equally, individuals regularly show behaviours that are based on family impacts be it healthy or unhealthy reactions. According to Corey (2005), the family system model has three clear features (Sue et.al, 2010).
These features include (1) Personality development which is generally directed by family traits, particularly, how guardians behave towards and around their children (2) Abnormal behavior within an individual is more often a reflection or a sign of unhealthy family dynamics and, more specifically, of poor communication among family members. (3) The focus of the therapist must not be exclusively on the individual but also on the family system and endeavour to include the whole family in the treatment. Hence, the locus of disorder apparently resides not inside the individual but inside the family system. Critics have expressed worry that the family system model may have negative results. Over and over again, guardians of children who experience certain disorders have been blamed by clinicians, notwithstanding the wealth of proof that parental impact may not be a factor in those disorders. The guardians are then troubled with unnecessary guilt over a circumstance they couldn’t have in any case controlled.
Furthermore, according to Sue et al. (2010), efforts to explain the humanistic – existential model of abnormal behavior, is a big problem. The humanistic and existential models came out as a response to the first models of mental illness the humanistic existential model share a set of ideas that makes them very from other approaches. The first idea is that people have realities that results from their experiences and perceptions about the world. How a person interprets an event is more important than the events itself, hence the clinician recreates the world from the patient’s point of view in order understand why they behave the way they do. The second idea shared by both models is that the individual has free will to choose and take responsibility of his actions and decisions. This approach also believes that the will to live their lives to suit them.
For the humanistic approach, psychologists Carl Rogers and Abraham Maslow argued that people are motivated by self-actualizing tendency which makes them want to be better. Self concept is the way an individual assesses his worth and value. When society forces conditions of worth on a person, an individual develops abnormal behaviour and as such sees self-actualization tendency and self-concept as not being congruent. The existential approach is a set of attitudes. Existentialism compared to humanism is less optimistic because it focuses on the challenges and irrationalities that people face in life. The existential approach also stresses on responsibility to others.
Lastly, there is the behavioral models of mental illness. Sue et al. (2010), purports that the behavioral models of mental illness stress on the function of learning in abnormal behaviour and their explanations of how learning takes place indicates their distinctions (Corey, 2005; Kottler, 2002). The three learning theories are classical conditioning, operant conditioning and observational learning. Classical conditioning discovered by Ivan Pavlov is learning where responses to new stimuli is learnt by forming an association between old stimuli and the new stimuli by constantly and repeatedly pairing them for some time.
For classical conditioning in mental illness, JB Watson identified the relevance of associative learning in explaining abnormal behaviour. JB Watson used an experiment to prove that phobias, deviant attraction and other extreme emotional responses were learnt through classical conditioning. For instance, little Albert learnt to be afraid by linking rats to loud noises. Operant conditioning theory suggest that results that follow behaviours controls those behaviours. Operant conditioning makes use of reinforcement and Punishment concepts. Operant conditioning in psychopathy study the relationship between environmental reinforcers and mental illnesses. Principles of operant conditioning helps to explain abnormal behaviours like self-injurious behaviours, hallucinations, delusional statements and some alcohol and substance abuse (Corey &Corey, 1995) (Sue et al., 2010).
For example, the pleasure that people suffering from alcohol abuse disorders derive from consuming alcohol is what makes the learn and continue consuming alcohol, in other words pleasure(consequence) controls their alcohol consumption (the abnormal behaviour). According to Sue et al. (2010), observational learning theory is of the view that people learn new behaviours by watching others execute them (Bandura, 1997; Cormier & Cormier, 1998). Vicarious learning is learning by watching others perform a behaviour and later copying them. In observational learning reinforcement is not necessary but it plays a role in maintaining behaviour. Observational learning in psychopathy stresses on the fact that abnormal behaviours the same way normal behaviours are learnt according to James and Gillard (2003) that is a person learns abnormal behaviour that he is exposed to.
In conclusion, each model is based on a unique set of assumptions, and have each given rise to a unique set of achievements although they have their limitations. These models contribute to the explanation and understanding of mental illnesses from different point of views.