MODULE 15: BIOPSYCHOLOGY OF PSYCHIATRIC DISORDERS

• Schizophrenia 

• Depressive Disorders 

• Anxiety Disorders

What are the most common mental disorders?

Positive Symptoms

• These are symptoms that seem to represent an excess of typical function 

• It include bizarre behavior, hallucinations, ambivalence, abnormal thought form, and delusions 

Negative Symptoms

• These are symptoms that seem to represent a reduction or loss of atypical function 

• It include alogia, affective flattening, anhedonia, attention impairment, avolition, asocial behavior, anergia

Disorganized Symptoms

• These are symptoms that shows disorganized behaviors 

• It includes disorganized speech, inappropriate affect, and disorganized behavior

• Genes

• Biological basis

• Early experiential factors

What are the causal factors of schizophrenia?

Chlorpromazine

• It was discovered in 1950s as the first antipsychotic drug used to treat schizophrenia

• It was originally an antihistamine given to patients before surgery 

• It was concluded that it could be given to difficult-to-handle patients with psychosis

Reserpine

• It is an active ingredient of the snakeroot plant that was discovered shortly after the discovery of chlorpromazine 

• It acts as an antipsychotic that helps alleviate psychotic symptoms among patients 

• It is no longer used as a treatment of schizophrenia as it produces a dangerous decline in the blood pressure at the doses needed for successful treatment

Atypical Antipsychotic Drug

• Also known as the second-generation antipsychotics 

• They work effectively to alleviate the psychosis symptoms without producing Parkinsonian side effects

Depressive Disorders

• common feature of these disorders is the presence of sad, empty, or irritable mood, accompanied by somatic and cognitive changes that makes an individual dysfunctional 

• It is characterized by discrete depressive episodes of at least 2 weeks duration

Iproniazid

first antidepressant drug in the market 

Monoamine Oxidase Inhibitors

It increases the levels of monoamine such as norepinephrine and serotonin by inhibiting the activity of monoamine oxidase (MAO) that breaks down monoamine neurotransmitters

Tricyclic Antidepressants

It blocks the reuptake of the norepinephrine and serotonin from synapses, thus increasing their levels in the brain

Imipramine

• first tricyclic antidepressant which initially thought to be an antipsychotic drug 

• They are safer alternative to MAO inhibitors

Selective Serotonin-Reuptake Inhibitors (SSRIs)

It blocks the reuptake of serotonin from synapses

Fluoxetine (Prozac)

first SSRI in the market

Deep Brain Stimulation

• implanted under the skin to deliver continual impulses of electrical stimulation that could not be detected by the patients

• a therapeutic effect among depressed patients who have failed to respond to other treatments

Anxiety and Anxiety Disorders

• a chronic fear that persists in the absence of any direct threat 

• a common psychological correlate of stress 

• adaptive if it motivates effective coping behaviors

Chlordiazepoxide (Librium) and Diazepam (Valium)

widely prescribed anxiolytic drug

Benzodiazepines

• also prescribed as hypnotics, anticonvulsants, and muscle relaxants

• prescribed for a short-term use only as it is highly addictive 

• act as GABA agonist that gives a calming and relaxing effect to the patient

Serotonin Agonists

• Buspirone produces anxiolytic effects without producing ataxia, sedation, and muscle relaxation unlike in benzodiazepines 

• However, it’s side effects are dizziness, nausea, and headache

Antidepressant Drugs

often effective against anxiety disorders and anxiolytic drugs are often effective against clinical depression